Re: [Elecraft] OT: Wiring A Continent : The U.S. Transcontinental Telegraph Line

[Alan Bloom]

And the line was completed while the Civil War was raging.  Amazing!

Alan N1AL


On 11/21/23 13:43, Wayne Burdick wrote:

I highly recommend this fascinating first-person account. You might want to 
skim over the parts about political infighting to get to descriptions of the 
route, procurement of poles, Indian encounters, and inclement weather.

(And we thought Field Day setup was challenging.)

http://www.telegraph-history.org/transcontinental-telegraph/index.html

73,
Wayne
N6KR


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Re: [Elecraft] OT: The day I found out I was going to be an engineer

[Alan Bloom]

On 9/17/23 23:05, John Gay wrote:

...
  Not much later I’d taught myself to solder and built a Knightkit Star Roamer.


Ah yes, the Star Roamer, my first "real" receiver.  (The actual first 
was a homebrew 1-tube regen.)


I feel like one of the Old Timers when I was young talking about their 
spark transmitters.  :-)


Alan N1AL

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Re: [Elecraft] CM-500 Question

[Alan Bloom]

Thanks Jim.  Unfortunately I'm several thousand miles away from home so 
I can't do that test right now.  I'm pretty sure it's an electret, but 
I'll check when I get home.


Alan N1AL


On 8/7/2023 11:00 PM, Jim Brown wrote:

On 8/7/2023 12:44 PM, Alan Bloom wrote:
I also use it for recording a radio show on a computer sound card. 
Again, I have to set the gain to near maximum to get proper levels.


Alan,

The CM500 has always had an electret mic, which requires bias, 
although the data sheet has always called it a dynamic mic. As a test, 
turn off bias and see if that changes anything. If it is a dynamic, 
turning off bias should make it work better.


My WAG is that what you bought might be a counterfeit. My experience 
buying all sorts of things in the last 5 years (kitchen tools, shoes, 
etc.) has been seeing lots of what appear to be either counterfeit or 
cheapened versions of stuff I'd previously owned and wanted a second one.


73, Jim K9YC



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Re: [Elecraft] CM-500 Question

[Alan Bloom]

I bought a CM-500 not too long ago.  (I think it was late last year.)  I 
don't have any way to compare it to earlier production, but this one 
does seem to have low microphone sensitivity.  On the K4 I have to turn 
on the preamp and set the mic gain to maximum to get 5 on the ALC meter 
at normal speaking levels.


I also use it for recording a radio show on a computer sound card. 
Again, I have to set the gain to near maximum to get proper levels.


By the way, for the radio show I use the equalizer in Audacity to boost 
the bass.  Apparently the CM-500 is meant for communications use so 
doesn't have as good bass response as the mic I used to use.


Alan N1AL


On 8/7/2023 7:46 PM, Larry Martin wrote:

I purchased a CM-500 over 10 years ago when I first got my K3.  K3 is still 
going strong but the headset died a couple of years ago and has since been 
discarded.  I've read several comments that the current CM-500's don't have as 
good of a microphone as the earlier ones.  Does anyone have any experience on 
the latest batch of them?  I always received great audio reports on my old 
setup and need to purchase another headset.  Just wanted some feedback before 
buying another CM500.

Much appreciated



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Re: [Elecraft] K4 and Yamaha CM-500 Mic?

[Alan Bloom]

I had never used my CM-500 on a K3 so I can't do that comparison. But on 
the K4 I had to turn on the internal mic preamp and set the mic gain all 
the way to maximum.  That seemed to give about the correct level - I 
could talk at normal loudness to get 5 on the ALC.


I also use the CM-500 on my laptop to record a radio show.  I had to 
turn up the gain close to max on the computer as well.  I think 
late-production CM-500s just tend to have low microphone sensitivity.


Alan


On 7/31/2023 1:40 AM, Oscar Staudt wrote:

When I got my K4D a month ago, I unplugged my Yamaha CM-500 mic and
headphones from my K3, and plugged them into the back of my K4.  I set the
mic input to rear, and mic bias on.  I expected the mic to perform
like it had in the K3.


I attempted to get 3-5 bars of ALC by turning up the mic gain control.  Even
with the gain up to 80, I’d have to speak *very* loudly to just get a
flicker on the ALC meter.


I then went back into the mic configuration and turned on the preamp (14dB).
After that I could get  some ALC bars with the mic gain around 65 or more.  But
I still  had to talk much louder than I had to with the same mic on the K3.
(note:  mic level on the K3 was set around 7).


Question:  Is it reasonable to expect that I’d have to have the mic gain at
such a high level - and still have to talk louder than my normal (K3)
level?


BTW, I can hook up the MH-4, switch to front mic, and all works smooth with
mic gain around 12.
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Re: [Elecraft] [OT] A dumb question about lightning

[Alan Bloom]

Hi Al,

The "Bible" on this subject that has been used for many years by the 
telecommunications industry is Motorola's "R56, Standards and Guidelines 
for Communications Sites":


https://www.blm.gov/sites/blm.gov/files/Lands_ROW_Motorola_R56_2005_manual.pdf

It's kind of complicated, but it's what you have to do if you really 
want to protect your site.  Of special interest are Chapter 4 "External 
Grounding (Earthing)", Chapter 5 "Internal Grounding (Earthing)", and 
Chapter 7 "Surge Protective Devices".


Alan N1AL


On 7/28/2023 10:31 PM, Al Lorona wrote:

Please don't laugh at me; I'm a transplant from a region of the country with 
essentially no lightning to a region where you have to worry about it quite a 
bit.

We had a doozy of a storm last night, with lots of lightning overhead. I felt 
like a sitting duck, even though I had grounded both sides of the balanced 
feedline of the antenna, switched the antenna switch to the middle (grounded) 
position, and even disconnected the coax leading to the K3's rear-panel antenna 
port.

Whenever lightning happens, I always wonder if it really is in fact better to 
ground everything. Because, doesn't that essentially make a lightning rod of 
the antenna? If I simply disconnected the antenna and left it floating, 
wouldn't it be less likely to attract a lightning bolt?

I'm of the belief that it's better to try to avoid a direct hit than to attract 
one and trust your grounding system to do its thing. I'm of the belief that no 
grounding system is perfectly effective.

Al  W6LX/4

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[Elecraft] Friedrichshafen

[Alan Bloom]

Since I found  myself less than a 6-hour drive away from 
Friedrichshafen, Germany this weekend, I decided to cross something off 
my bucket list and attend the world-famous amateur radio convention.


Several people told me that the event was smaller than in previous 
years, but it still was impressive.  The Elecraft booth seemed to have a 
constant crowd around it.  Eric and the others manning the booth were 
busy all weekend.


Eric's Elecraft update presentation Friday at noon was standing-room 
only.  He reviewed the K4 and upcoming new firmware and products.  I 
should have taken notes.  I remember him discussing the VHF/UHF module 
and several firmware enhancements.


The flea market filled a large hall.  I am told that last year is was a 
hall and a half.  It took me almost two hours to go through it  The 
items on display were mostly familiar from US ham flea markets I have 
attended.  I was surprised to see a fair amount of old Collins gear - 
e.g. a complete Collins S-line in very good condition for 1600 Euros.  I 
noticed a lot more microwave equipment and parts than is usual in the 
US.  I think that microwave operation is more common in EU.


Alan N1AL




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Re: [Elecraft] P3 error

[Alan Bloom]

It's the MENU:CenterEn function.  When OFF, the center key does not 
adjust the center frequency when in tracking mode.


Alan N1AL


On 4/25/23 08:06, ROBERT GARCEAU wrote:

When i press the Center button on my P3, I get a "center key disabled" message.
I have been trying to find the problem. No success.
Bob, W1EQ
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Re: [Elecraft] Where to put the wattmeter

[Alan Bloom]

There's no reason the P3 can't display it if you have a way to generate 
the trapezoidal pattern from the transmitter.  I think feeding a 
triangle wave from a function generator into the mic input would do it.


Alan N1AL



On 4/19/23 16:38, Fred Jensen wrote:
and I'd buy one if it would do a trapezoidal pattern.  Judging TX 
signal quality looking at the time-domain envelope is pretty hard, but 
I can judge straight sides on the T-pattern


73,

Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County


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Re: [Elecraft] Where to put the wattmeter

[Alan Bloom]

I changed the Subject line since this is a new topic.

If the wattmeter (in this case the P3 sensor) is placed after the tuner 
then it will read the SWR of the antenna.  To determine the net forward 
power, just subtract the reflected power from the forward power.


To calculate reflected power, use the equation:

P(ref) = P(fwd) * [(SWR-1)/(SWR+1)]^2

Since the K3 and K4 already have a built-in wattmeter located before the 
tuner, it makes sense to me to put the P3 sensor (or external wattmeter) 
after the tuner so you can see what is going on with the antenna.


Alan N1AL



On 4/10/23 09:02, Bob McGraw wrote:


My question would be "where is the sensor for the P3 located in the 
feed system?"  It should be between the KPA500 output and the KAT500 
input.   Therefore, when the KAT500 resolves a match, then the line 
between the KPA500 output and KAT500 input is nominally 50 ohms.


If the sensor is located after the KAT500, thus in the feedline to the 
antenna, the impedance and thus the voltage on the line, will impact 
the the indicated value.   Most all power reading sensors are voltage 
reading devices, referenced to 50 ohms nonreactive and should be 
located in a 50 ohm line which has a nonreactive load. Most power 
indicating devices are calibrated for 50 ohms.   There are some 
exceptions.


As example;  if the impedance of the antenna is reactive ( most are ) 
and about 200 ohms Z  being fed though 50 ohm coax for the feedline 
and the power is 500 watts, the voltage is about 316 volts.    If the 
impedance were 50 ohms and the power is 500 watts the voltage would be 
about 158 volts.   Here it is easy to see, using a voltage sensing 
circuit, the power indication would be incorrect by some significant 
magnitude.


I've considered adding a power/SWR monitor to my P3 but it would be in 
the coax to the antenna.  I use the internal tuner in my K3S to 
resolve a match, thus the power measurement would be after the ATU in 
the radio and the actual load Z is really unknown.   The only way to 
determine if the power indication is correct with the P3 is to use a 
50 ohm dummy load or place it in the RF path which is 50 ohms 
nonreactive.


73

Bob, K4TAX


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Re: [Elecraft] [P3] P3 woes - repaired but now claims my K3s puts out 873W!

[Alan Bloom]

Hi Dave,

There is a "SensorCal" entry in the Transmit Monitor Menu, but I don't 
think it has enough range to correct such a large error.


There is also a "MtrScale" entry to set the full-scale power on the 
meter display.  Does the reading change when you change the scale?


In addition to the I/O board, the problem could also be on the Sensor 
board (the small board that connects the sensor RJ45 connector to the 
I/O board).  If one of the resistors on this board went open or shorted 
it could cause a power error.  Is the reverse power reading way off as 
well?  (i.e. does the SWR read wrong for SWR not close to 1:1?)  If so, 
that could be due to a resistor problem on the Sensor board.


> I'm wondering if the new revision I/O board is somehow incompatible 
with the older TX Monitor board,


No I don't think so.  There was a minor change in the sensor design at 
one point but it was just a capacitor change to improve the detected 
bandwidth so the envelope would display correctly.  (The same sensors 
are used for the W2 wattmeter.)


73,

Alan N1AL



On 4/7/23 12:12, Dave New, N8SBE wrote:

So, I was the guy that had a P3 display/boot problem recently.

I sent it to the mother ship for repair, and they found that (get 
this) the 12V supply was shorted to the 3.3V supply (eep!).
So, a new(er) I/O board (which contains the supplies) and a 
replacement blown 3.3V LCD controller later, I have an (almost) fully 
functional P3 again.


EXCEPT, the TX Monitor function is now funky.  It claims that my K3s 
is putting out 873 (or so) watts!  I've tried both sensors (I had a 
200W HF sensor on the shelf since I added a KPA500 and changed to a 
2KW HF sensor), and although the scale max changes on the P3 display 
when I change sensors, it still way overstates my output power.  The 
KPA500 is showing 1360 watts on the P3!


I unplugged/re-plugged everything, did a visual inspection of the TX 
Monitor adapter board under a lighted magnifying glass, looking for 
missing/broken SMD resistors or caps, but so far no soap.


I'm wondering if the new revision I/O board is somehow incompatible 
with the older TX Monitor board, or maybe there is a missing 1M-ohm 
resistor to ground on the I/O board at the sensor connector, or an 
incorrect series resistor value there.


And yes, I sent a note to support, but I haven't heard back, yet. 
Wondering if anyone (Alan?) has any ideas where this behavior is 
coming from.  The wattmeter in both my K3s and KPA500 are working 
normally.  It's just the P3 wattmeter that's gone off the deep end, now.


Thanks, and 73,
-- Dave, N8SBE
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[Elecraft] OT: Hiram Maxim in the news

[Alan Bloom]

Hiram Maxim, inventor of the Maxim machine gun, was the father of Hiram 
Percy Maxim, a founder of ARRL:


https://news.yahoo.com/ukraines-troops-fight-off-massive-214437031.html

Alan N1AL

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[Elecraft] Vertical antennas Was: KX3 and KPA1500 compatibility

[Alan Bloom]

On 3/6/23 15:08, Jim Brown wrote:
Most (but not all) verticals need radials to transmit a decent signal. 
A vertical that needs radials is a lousy TX antenna without them.


Right.

I use a 6BTV, which is a 6-band trap vertical about 24 ft tall. With a 
barefoot K4 at 100W I get out quite well.  Obviously I can't compete 
with the "big guns" running kilowatt amplifiers and beams at 120 feet, 
but I do work lots of DX.  I can crack most pileups with enough patience.


The trick is that the antenna has 40 radials, each one 32 ft long buried 
an inch or two in the sand at my desert location.


The old joke that a vertical is an antenna that radiates equally poorly 
in all directions is only true if you have a poor radial system.


Alan N1AL

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Re: [Elecraft] [P3] P3 woes - internal display inop

[Alan Bloom]

By the way, I no longer have a K3 or P3 (lost in a house fire) so this 
is from memory...


> Since the internal display seems to show OK, no matter how briefly,
> I'm thinking this is not an internal display connection issue.

Agreed.

> This seems to be a power on reset issue of some sort.

Can you send/receive RS-232 commands to the P3?  If so, then the power 
must be on.


If you haven't already, I would try moving the power-on jumper (on the 
rear-panel I/O board at the back of the P3) to the "always on" position 
(jumper pins 1 and 2).


> I take it that the 3.3V supply is 'on' as long as 12V external is 
supplied to the P3?


No, it's only on when the P3 is on.

What happens is that when the P3 CPU wakes up, one of the first things 
it does is to enable the PWON signal to the I/O board which holds the 
power on.  If that is not working for some reason, then moving the 
power-on jumper to "always on" should force the P3 to stay on.


Alan N1AL




On 2/26/23 12:22, Dave New, N8SBE wrote:

Alan,

Before I got the chance to look into your idea of possibly bad display 
connection,
I DID reload a saved configuration into the P3 using the P3 Utility, 
and it restored

the high-res setting on the external display.

After power cycling (the generator quit unexpectedly due to a low oil 
sensor),
now I can't get the external display on at all, but interestingly, the 
internal
display comes up briefly with the P3 Boot Loader and Checksum Test 
messages, and
if it's been a while since I've tried to power up, I get a brief 
spectrum display
with the message, Waiting for SVGA, then it goes blank, apparently 
with an internal
power fail, since every time I push the Power button, I get the same 
sequence.


Since the internal display seems to show OK, no matter how briefly, 
I'm thinking this

is not an internal display connection issue.

This seems to be a power on reset issue of some sort.  I note from the 
schematic that
that Power button feeds SW_ON which is tied to INT4/A15 on the PIC33F 
chip.  I'm assuming
the PIC has that pin programmed for INT4, so pushing the Power button 
is 'waking up' the PIC33F
with INT4, and it goes partially through the start up, and then fails 
apparently failing to

latch 'on' from the momentary push button press.

I take it that the 3.3V supply is 'on' as long as 12V external is 
supplied to the P3?


Thanks,
-- Dave, N8SBE

On 2023-02-24 13:23, Alan Bloom wrote:

Hi Dave,

Another possibility is that perhaps one of the display connectors has
come loose or is making a bad connection.

I normally wouldn't recommend this since these tiny connectors are
kind of tricky, but since the P3 isn't working anyway, there's nothing
to lose.

There are two surface-mount connectors located underneath the display
on the front-panel board: a 4-pin connector for the display backlight
and a 40-pin connector for the rest of the display electronics.

To access them, remove the front-panel board from the P3 and then
remove the LCD display by gently prying it free from the rubber
holder.  Be careful so as not to put stress on the flex circuits going
to the two connectors.

Examine each of the connectors to see if it looks like the flex
circuits are properly seated in them.  To re-seat one, open the
connector by using a fingernail to pop open the top.  After
re-positioning the flex circuit, press the connector top down again
until it clicks.

As I say, this is a rather delicate operation (which is why the front
panel came pre-assembled in P3 kits).  So you might want to consider
sending the P3 in for service and let the experienced Elecraft techs
handle it.

Alan N1AL



On 2/24/23 10:51, Dave New, N8SBE wrote:

Mike,

Thanks for the idea!  I hadn't considered that mitigation.

Anyone else have ideas for a permanent corrective action?

73,
-- Dave, N8SBE

On 2023-02-24 09:13, Mike Flowers wrote:

Hi Dave,

If you have a way of sending P3 control commands to the P3, there 
may be a

chance that you could the resolution of the external display set to a
useable value.

I've attached my copy of the P3 Programmer's Reference.

- 73 and good DX de Mike, K6MKF, NCDXC Life Member



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Re: [Elecraft] [P3] P3 woes - internal display inop

[Alan Bloom]

Hi Dave,

Another possibility is that perhaps one of the display connectors has 
come loose or is making a bad connection.


I normally wouldn't recommend this since these tiny connectors are kind 
of tricky, but since the P3 isn't working anyway, there's nothing to lose.


There are two surface-mount connectors located underneath the display on 
the front-panel board: a 4-pin connector for the display backlight and a 
40-pin connector for the rest of the display electronics.


To access them, remove the front-panel board from the P3 and then remove 
the LCD display by gently prying it free from the rubber holder.  Be 
careful so as not to put stress on the flex circuits going to the two 
connectors.


Examine each of the connectors to see if it looks like the flex circuits 
are properly seated in them.  To re-seat one, open the connector by 
using a fingernail to pop open the top.  After re-positioning the flex 
circuit, press the connector top down again until it clicks.


As I say, this is a rather delicate operation (which is why the front 
panel came pre-assembled in P3 kits).  So you might want to consider 
sending the P3 in for service and let the experienced Elecraft techs 
handle it.


Alan N1AL



On 2/24/23 10:51, Dave New, N8SBE wrote:

Mike,

Thanks for the idea!  I hadn't considered that mitigation.

Anyone else have ideas for a permanent corrective action?

73,
-- Dave, N8SBE

On 2023-02-24 09:13, Mike Flowers wrote:

Hi Dave,

If you have a way of sending P3 control commands to the P3, there may 
be a

chance that you could the resolution of the external display set to a
useable value.

I've attached my copy of the P3 Programmer's Reference.

- 73 and good DX de Mike, K6MKF, NCDXC Life Member



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Re: [Elecraft] Checking out Elecraft on ChatGPT

[Alan Bloom]

On 2/17/23 14:14, kevin via Elecraft wrote:
If you want to copy and paste from the web it helps to add another 
step to the process.


Paste the selected text into a text processor such as WordPad on a 
Microsoft system or gedit on a Linux system.  Then copy the text 
again.  This will eliminate any formatting, fonts, or colors which 
don't fit your email application.


Paste that second copy into your email application and it should look 
much better.


OK, maybe third time's the charm:



Compare an Elecraft K3 with an Elecraft K4.

The Elecraft K3 and Elecraft K4 are both high-end Amateur Radio 
transceivers designed for performing radio operations in both the HF and 
VHF/UHF bands. The K3 is the predecessor to the K4, but both models 
offer top-of-the-line performance for their respective classes.


The K3 is an HF/VHF transceiver that offers up to 100 watts of power 
output. It features a dual-channel receiver, an optional roofing filter, 
and a built-in antenna tuner. It is a modular design, allowing users to 
customize their set up with additional modules, such as a digital voice 
recorder, remote control, and CW decoder.


The K4 is an HF/VHF/UHF transceiver that offers up to 200 watts of power 
output. It features a dual-channel receiver, roofing filters, and an 
integrated antenna tuner. It also includes a built-in digital voice 
recorder and a CW decoder. It also supports an optional remote control.


In terms of performance, the K4 is the superior of the two models, as it 
provides more power output, a broader range of frequencies, and 
additional features. However, the K3 is still a capable transceiver, and 
depending on the user’s needs, it may be the better option.


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Re: [Elecraft] Checking out Elecraft on ChatGPT

[Alan Bloom]

On 2/17/23 12:48, Dave New, N8SBE wrote:

Alan,

For starters where are all the spaces? :-)  Makes it hard to read, 
that's for sure.


That's weird.  The spaces were there in the sent message - they somehow 
disappeared in the reflected copy.;  Let's try again:


CompareanElecraftK3withanElecraftK4.

TheElecraftK3andElecraftK4arebothhigh-endAmateurRadiotransceiversdesignedforperformingradiooperationsinboththeHFandVHF/UHFbands.TheK3isthepredecessortotheK4,butbothmodelsoffertop-of-the-lineperformancefortheirrespectiveclasses.

TheK3isanHF/VHFtransceiverthatoffersupto100wattsofpoweroutput.Itfeaturesadual-channelreceiver,anoptionalroofingfilter,andabuilt-inantennatuner.Itisamodulardesign,allowinguserstocustomizetheirsetupwithadditionalmodules,suchasadigitalvoicerecorder,remotecontrol,andCWdecoder.

TheK4isanHF/VHF/UHFtransceiverthatoffersupto200wattsofpoweroutput.Itfeaturesadual-channelreceiver,roofingfilters,andanintegratedantennatuner.Italsoincludesabuilt-indigitalvoicerecorderandaCWdecoder.Italsosupportsanoptionalremotecontrol.

Intermsofperformance,theK4isthesuperiorofthetwomodels,asitprovidesmorepoweroutput,abroaderrangeoffrequencies,andadditionalfeatures.However,theK3isstillacapabletransceiver,anddependingontheuser’sneeds,itmaybethebetteroption.
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[Elecraft] Checking out Elecraft on ChatGPT

[Alan Bloom]

The latest fad in AI (Artificial Intelligence) is ChatGPT, now supported 
on Google and other platforms.  I think of it as a "super Google" where 
you can ask questions and get detailed answers.  Just for grins I 
entered the following request with the following answer.  The response 
"sounds" very authoritative, but see if you can spot all the errors. :=)


Alan N1AL

CompareanElecraftK3withanElecraftK4.

TheElecraftK3andElecraftK4arebothhigh-endAmateurRadiotransceiversdesignedforperformingradiooperationsinboththeHFandVHF/UHFbands.TheK3isthepredecessortotheK4,butbothmodelsoffertop-of-the-lineperformancefortheirrespectiveclasses.

TheK3isanHF/VHFtransceiverthatoffersupto100wattsofpoweroutput.Itfeaturesadual-channelreceiver,anoptionalroofingfilter,andabuilt-inantennatuner.Itisamodulardesign,allowinguserstocustomizetheirsetupwithadditionalmodules,suchasadigitalvoicerecorder,remotecontrol,andCWdecoder.

TheK4isanHF/VHF/UHFtransceiverthatoffersupto200wattsofpoweroutput.Itfeaturesadual-channelreceiver,roofingfilters,andanintegratedantennatuner.Italsoincludesabuilt-indigitalvoicerecorderandaCWdecoder.Italsosupportsanoptionalremotecontrol.

Intermsofperformance,theK4isthesuperiorofthetwomodels,asitprovidesmorepoweroutput,abroaderrangeoffrequencies,andadditionalfeatures.However,theK3isstillacapabletransceiver,anddependingontheuser’sneeds,itmaybethebetteroption.
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Re: [Elecraft] [Elecraft-KX] Peter Martinez And The CW-To-PSK31 Feature

[Alan Bloom]

Some would argue there's no activity in ham radio, or perhaps life itself,
more rewarding than making RTTY contest QSOs using a 1 pound radio with a
whip and an attached keyer paddle


You mean I no longer need my 75-pound Model 15 Teletype machine to 
send/receive RTTY?


:=)

Alan N1AL


On 2/5/2023 6:30 PM, Wayne Burdick wrote:

Hi Tony,

I, too, am an avid user of the CW-to-PSK31 feature, which is available on the 
K3 and K4 as well as the KX line. I've even used it during Field Day, which is 
a hoot, especially with a tiny KX2 and its paddle being all the gear you need 
(no computer or keyboard required). All of these rigs also do CW-to-RTTY with 
the keyer paddle.

Some would argue there's no activity in ham radio, or perhaps life itself, more 
rewarding than making RTTY contest QSOs using a 1 pound radio with a whip and 
an attached keyer paddle while operating pedestrian mobile :)

Of course I may be biased, being the nut-case who dreamed this up and wrote the 
MCU firmware. But I'd also like to give credit where it's due: the DSP code for 
this was written by Lyle Johnson, KK7P.

One tip for those using PSK31 as a casual operating mode: you may need to use 
RIT or XIT to fine-tune the offset and obtain the best copy.

73,
Wayne
N6KR



On Feb 4, 2023, at 9:57 PM, Tony <73gu...@gmail.com> wrote:

All:

I spoke with Peter Martinez about a video I posted that shows how the Elecraft 
CW-to-Data mode works with PSK31. Peter developed the mode some 25 years ago so 
I thought it would be interesting to ask if he ever imagined it being used in 
such a unique way. To my surprise, he wasn't aware it existed!

He mentioned that it could be difficult for some to send fast enough to keep up 
at PSK31 speeds, but I assured him that slower speeds are adequate to make 
contacts and that I've used it many times when operating QRP portable.

I'm not sure how often it's used among the group, but I find it useful to 
switch from CW to PSK31 after the contacts dry up and I always get a kick out 
of the reaction I get when I mention how I'm sending PSK31. I suspect there's a 
slight advantage in weak-signal performance over CW as well which doesn't hurt 
when running QRP.

Here's the video link: https://www.youtube.com/watch?v=-9uoSbYhe00

Tony -K2MO
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Re: [Elecraft] HW-16

[Alan Bloom]

Its long-term utility was limited by the one-year non-renewable Novice license 
of that era.



It actually was a pretty good CW rig.  I used it long after I upgraded 
from Novice.  W1AW used one for their Novice station for awhile.


It had true full break-in that worked perfectly.  The receiver came 
standard with a 500 Hz crystal filter.  With the external HG-10 VFO you 
had separate stable transmit and receive VFOs so working split was not a 
problem.


Alan N1AL


On 7/3/22 14:54, Mike Morrow wrote:

I don't know what an HW-16 is.

The HW-16 is a vacuum tube, 90-watt (maximum) input, crystal-controlled CW-only 
Novice-band transmitter and receiver kit with built-in AC power supply.  It covered the 
CW portion of only 80m, 40m, and 15m.  It was sold by Heath from 1967 to 1976.  Its 1967 
kit price was "only" $110, but that's equivalent to almost $1000 in 2022.  
Adjusted for inflation my full-house KX2 50 years later was less expensive.
  
The HW-16 was popular when I was WN5WGJ in 1968, but at age 16 I could never have afforded one. :-)  Its long-term utility was limited by the one-year non-renewable Novice license of that era.
  
Mike / KK5F


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Re: [Elecraft] I/Q details for the KX3.

[Alan Bloom]

But I think that SDRs that digitize at the VFO frequency itself (I believe
this is generally called "direct sampling" on RX and "direct digital
synthesis" on TX?) can get away with a single channel, since there's no
mixer to cause the "you mix A and B and get both A + B and A - B even
though you only wanted one of them" problem.


Yes, but...  You still need to reduce the sample rate to a lower value 
that the DSP can handle.  Either you need to mix down to a low-frequency 
IF or all the way down to an I/Q signal at a zero Hz center frequency.  
Either way, the mixer needs to be quadrature to avoid the image.


The output of the ADC goes to a quadrature digital downconverter (DDC), 
which consists of two digital mixers (that multiply the ADC signal times 
the digital local oscillator), with the local oscillator to each mixer 
90 degrees out of phase.  In this P3 this is done in an ASIC 
(application-specific IC) and in the K4 it is done in an FPGA.


Alan N1AL


On 6/22/22 20:45, Julia Tuttle wrote:

Mike,

I think you're right that SDRs that digitize at a zero IF (like the KX3)
need I and Q channels to distinguish the AF sidebands. That is, if the
radio mixes 7030.4 kHz down to a sidetone of 0.4 kHz, it also catches
signals at 7029.6 kHz.

And I think that SDRs that digitize at a non-zero and 'properly
intermediate' IF (that is, neither 0 nor the VFO frequency) also need I and
Q channels to distinguish the IF 'sidebands'. That is, if the radio mixes
7030 kHz down to an IF of 455 kHz, it also catches signals at 6120 kHz.

But I think that SDRs that digitize at the VFO frequency itself (I believe
this is generally called "direct sampling" on RX and "direct digital
synthesis" on TX?) can get away with a single channel, since there's no
mixer to cause the "you mix A and B and get both A + B and A - B even
though you only wanted one of them" problem.

Does this match your understanding?

Thanks,

Julie

On Wed, Jun 22, 2022 at 2:04 PM Mike Markowski  wrote:


Jerome,

This answer is for generic SDRs, since I don't have a KX3.

An SDR always must use both I and Q, even for CW.  I and Q are two
streams of samples of the same signal.  One of many advantages to i/q
sampling is the ADC's can run slower (cheaper).  In the extreme and
ignoring the intrusion of real life components on sampling, a 10 kHz
wide signal could be sampled with I and Q ADCs running at 10 kHz.
Nyquist is satisfied because you have 2 streams, or 20 kHz sampling in
this example.  Aliasing prevents you from using just I in that case.

The fact that Q is 90 deg from I, means we can plot them on axes 90 deg
apart.  That allows re-appropriating the entire field of complex
mathematics to work with the samples.  I and Q are both physical -
trying to avoid the word 'real'! - streams of samples, but I can be
called real and Q can be called imaginary.  Using Euler's Formula, they
can be bundled into a concise exp(j phi) formulation to work with.

I/Q imbalance is always a concern.  Maybe others can quantify it better
than me saying smaller is better.  :-)

73 es GL!
Mike ab3ap

On 6/21/22 11:08 PM, JEROME SODUS wrote:

Hello,

Although I have asked some of these questions on another forum, here I

have expanded on them a bit.

When the KX3 transmits a CW-signal, are both I and Q used?
If so, why would that be necessary?
(My guess is only the I is needed.)

Same questions too for a SSB-signal.

But, for any digital transmission like RTTY, FT8, or Olivia, wouldn't

both I and Q would be active?

The LO is used for the "In Phase" and is delayed by 90 degrees for the

"Quadrature"; how is that delay done?

How much can the delay deviate from 90 degrees and still be useful?

My reason for asking is that I'm to give a talk to the Radio Club in

August about how a KX3 works and want to mention these details.

TIA for any replies.
73 jerry km3kKX3#6088
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Re: [Elecraft] KX3/KPA100/Powerwerx Question

[Alan Bloom]

Dein Englisch ist viel besser als mein Deutsch!


On 6/10/22 15:44, df...@darc.de wrote:

Or this. While vacuuming it’s recommended to block the fan so it cannot rotate. 
In some cases, when the blades are driven bei the airflow too fast, the fan 
works as a generator and sends some voltage into the unit - which can be 
harmless but also can destroy sensitive electronics (if there is any inside the 
supply).


73
Hans, DF3DD

(Please forgive my english, it was 50something years ago when I learned it at 
school. And forgive if I write naturalnesses instead of real hints.)



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Re: [Elecraft] I need a Sherlock Holmes (weird spurs on 40m) [resolution]

[Alan Bloom]

Mystery solved!  The spurs appear to be coming from a solar installation 
on a house about 1/2 mile (3/4 km) from my house.


One interesting point is that the spurs do not go away at sundown, but 
continue until fairly late in the evening.  Apparently that solar 
installation must have some kind of battery to store the energy.


Solar panels are DC devices and do not themselves generate 
interference.  Rather it is the inverter(s) and other electronics that 
are the problem.  There are two kinds of solar systems -- the ones with 
all the panels in series feeding a single inverter and the kind with a 
separate inverter for each panel.  The latter is the kind I had on my 
house in California before it was destroyed in a fire and I never had a 
noise problem.  I have heard that the single-inverter systems are more 
troublesome from an RFI standpoint.  There was an article in April 2016 
QST magazine about how to mitigate RFI from solar systems.  ("Can Solar 
Power and Ham Radio Coexist?" by Tony Brock-Fisher K1KP)


--

The story:  I finally go around to walking around the neighborhood with 
my KX2.  I only have the AX1 antenna for it, which is not resonant on 
the 40 meter band, and I was not using a counterpoise so I could barely 
hear the signal from in front of my house.


I started walking south down the street but the signal seemed to be 
getting weaker.  So I turned around and walked north.  The signal was 
getting slightly stronger the farther I went.  I turned right at the end 
of the street onto another street and it kept gradually getting a little 
stronger.  At one point I suspected it might be coming from a Montessori 
school, but when I walked down the access street toward it it didn't get 
any stronger.  Plus with everything in the news these days I didn't 
think it would be a good idea for a strange man holding a strange 
contraption to be walking around the school grounds.  :=)


So I kept walking down the main street and within a couple blocks the 
signal started to rapidly increase in strength.  It peaked in front of a 
certain house, strongest at the right side of the house. Sure enough 
there are solar panels on that side of the roof.  The signal was peaking 
about S4 or S5 on the KX2 S-meter.  Again, this is with a non-resonant 
antenna with no counterpoise.


As I mentioned, the spurs are about S6 on the ground-mounted trap 
vertical at my house and they are almost buried in the noise when the 
band opens up at night.  So I'm not going to bug the neighbor about it.  
But I bet they would have trouble trying to listen to AM radio at their 
house.


Alan N1AL



On 6/7/22 17:21, Alan Bloom wrote:
As part of christening my new QTH/antenna/rig here at N1AL, today I 
did the test where I recorded all off-the-air spurious signals on all 
bands and then threw the main circuit  breaker for the house and did 
the measurement again, powering the K4 from a battery.  This is to 
identify any spurs that are coming from my house so I can do further 
sleuthing to figure out what is causing them.


One spur (or set of spurs) has me mystified.  It is a series of 
harmonics, with very stable frequencies, spaced at precisely 24 kHz, 
that extend from roughly 6.6 MHz to 7.4 MHz.  Each spur consists of a 
main carrier and a secondary carrier approximately 150 Hz lower in 
frequency and approximately 8 dB lower in amplitude.  The spurs are 
all the same amplitude, around -90 dBm (S6), dropping off as you 
approach 6.6 or 7.4 MHz.  I don't see these spurs on any other band.


The spur amplitudes did not change when I turned off AC power, so it 
can't be the rig's switching power supply or any other electronic 
device in the house.  It's nothing internal to the radio because if I 
switch to a dummy antenna the spurs go away.


So it's coming in through the antenna.  The antenna is a 6-band trap 
vertical about 30 feet from the house, with the coax coming 
underground to the shack.  We're on a large lot, there is a canyon 
(i.e. no houses) behind the property, and there is a vacant lot on the 
side where the antenna is located so the nearest houses in the 
neighborhood are about 150 feet away from the antenna.


The electric utility power lines switch from overhead to underground 
at our property line, about 150 feet away from the antenna. Internet 
is via cable, which is underground also.  Both power and Internet 
enter at the far end of the main house, which is over 100 feet from 
the shack, located in a granny unit.


I believe the exact fundamental frequency is 7007.03 kHz / 292 = 
23.9967 kHz, in case that's a clue.


Anyone have any ideas of what could be causing this?

Alan N1AL


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Re: [Elecraft] I need a Sherlock Holmes (weird spurs on 40m)

[Alan Bloom]

That's the strange thing about this.  It doesn't have a grinding sound 
or anything other than a clean carrier.  Actually two carriers, the 
weaker one about 150 Hz lower than the main one.  That pretty much rules 
out any kind of switching power supply, for example.


Maybe tomorrow I'll take my KX2 pedestrian mobile and walk around the 
neighborhood to see if the signal level changes.


Alan N1AL




On 6/7/22 19:36, jerry wrote:
On 40M I see noise every 15 kHz.  It's constant.  Sometimes stronger, 
sometimes
weaker, but it's always there.  The pattern is obvious on the 
waterfall display.

When I tune in one of the peaks, it sounds like a rhythmic grinding.

    - Jerry KF6VB



On 2022-06-07 16:59, Alan Bloom wrote:

The weird thing about these spurs is how clean and stable they are.
Switching power supply noise is generally not frequency-stable and it
is not a clean CW carrier.  This one is actually TWO clean carriers,
separated by about 150 Hz.

Alan N1AL


On 6/7/22 17:43, Fred Jensen wrote:
I did the "Main Breaker 2-Step" and nothing went away.  My noise on 
80 and 40 on the K3/P3 is highly varied ...


1.  Narrow discrete carriers [that appear linked, 25-35 kHz apart] 
come and go, sometimes within seconds


2.  Broad [5-10 kHz] bands of noise, often without any harmonic 
brethren [that I can find] that come in pulses that look like 
wide-band AMTOR


3. "Rope-like" noise on the WF, with and without harmonic brethren 
that often changes in character but mainly a primary signal 
oscillating back and forth in frequency over maybe 5 kHz.


Underground utilities, but we do have a 345 kV transmission line 
about two miles away that runs from a large power plant 5 or 6 miles 
east to somewhere up in OR near the Columbia. Sources are a mystery, 
but I've suspected harmonics of transmission line carrier-current 
signaling ... they really look like sometimes it's just idling, and 
then a burst of information.


73,

Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

Alan Bloom wrote on 6/7/2022 4:21 PM:
As part of christening my new QTH/antenna/rig here at N1AL, today I 
did the test where I recorded all off-the-air spurious signals on 
all bands and then threw the main circuit  breaker for the house 
and did the measurement again, powering the K4 from a battery.  
This is to identify any spurs that are coming from my house so I 
can do further sleuthing to figure out what is causing them.


One spur (or set of spurs) has me mystified.  It is a series of 
harmonics, with very stable frequencies, spaced at precisely 24 
kHz, that extend from roughly 6.6 MHz to 7.4 MHz.  Each spur 
consists of a main carrier and a secondary carrier approximately 
150 Hz lower in frequency and approximately 8 dB lower in 
amplitude.  The spurs are all the same amplitude, around -90 dBm 
(S6), dropping off as you approach 6.6 or 7.4 MHz.  I don't see 
these spurs on any other band.


The spur amplitudes did not change when I turned off AC power, so 
it can't be the rig's switching power supply or any other 
electronic device in the house.  It's nothing internal to the radio 
because if I switch to a dummy antenna the spurs go away.


So it's coming in through the antenna.  The antenna is a 6-band 
trap vertical about 30 feet from the house, with the coax coming 
underground to the shack.  We're on a large lot, there is a canyon 
(i.e. no houses) behind the property, and there is a vacant lot on 
the side where the antenna is located so the nearest houses in the 
neighborhood are about 150 feet away from the antenna.


The electric utility power lines switch from overhead to 
underground at our property line, about 150 feet away from the 
antenna. Internet is via cable, which is underground also.  Both 
power and Internet enter at the far end of the main house, which is 
over 100 feet from the shack, located in a granny unit.


I believe the exact fundamental frequency is 7007.03 kHz / 292 = 
23.9967 kHz, in case that's a clue.


Anyone have any ideas of what could be causing this?

Alan N1AL






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Re: [Elecraft] I need a Sherlock Holmes (weird spurs on 40m)

[Alan Bloom]

Hi John,

In this case the Internet is not via DSL, it's via cable.  The coax 
comes out of the ground and then to the modem/router and from there via 
a 150-foot Ethernet LAN cable to the granny unit, where there is an 
additional router with its own Wi-Fi.


Anyway, that entire system was turned off when I threw the main breaker 
to the house.  I assume it could be caused by Internet from some 
neighbor, but as I said, the nearest neighbor's house is about 150 feet 
away and all services are underground.


It's a puzzlement...

Alan N1AL



On 6/7/22 19:23, John Oppenheimer wrote:

Hi Alan,

I've had issues with the service from street to modem. As I understand,
there's a VDSL band which overlaps 7MHz band.

In my case, it was reversed, any transmission on 7MHz would disable TV
and Internet service.

John KN5L

On 6/7/22 7:54 PM, Alan Bloom wrote:

The ISP is TDS.  They offer up to 1 Gbps internet (I only pay for 200
Mbps) via cable.

Just as a sanity check, I just walked down to the main house and
unplugged the 150-foot LAN cable from the modem/router that feeds the
router in the granny unit here where the shack is.  As expected, the
spurs are still there.  There is no wired connection from the K4 or the
desktop computer to the LAN (Wi-Fi only).

Alan N1AL


On 6/7/22 18:29, John Oppenheimer wrote:

Hi Alan,

What is your TV/Internet provider?

John KN5L

On 6/7/22 6:59 PM, Alan Bloom wrote:

The weird thing about these spurs is how clean and stable they are.

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Re: [Elecraft] I need a Sherlock Holmes (weird spurs on 40m)

[Alan Bloom]

The ISP is TDS.  They offer up to 1 Gbps internet (I only pay for 200 
Mbps) via cable.


Just as a sanity check, I just walked down to the main house and 
unplugged the 150-foot LAN cable from the modem/router that feeds the 
router in the granny unit here where the shack is.  As expected, the 
spurs are still there.  There is no wired connection from the K4 or the 
desktop computer to the LAN (Wi-Fi only).


Alan N1AL


On 6/7/22 18:29, John Oppenheimer wrote:

Hi Alan,

What is your TV/Internet provider?

John KN5L

On 6/7/22 6:59 PM, Alan Bloom wrote:

The weird thing about these spurs is how clean and stable they are.

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Re: [Elecraft] I need a Sherlock Holmes (weird spurs on 40m)

[Alan Bloom]

The weird thing about these spurs is how clean and stable they are. 
Switching power supply noise is generally not frequency-stable and it is 
not a clean CW carrier.  This one is actually TWO clean carriers, 
separated by about 150 Hz.


Alan N1AL


On 6/7/22 17:43, Fred Jensen wrote:
I did the "Main Breaker 2-Step" and nothing went away.  My noise on 80 
and 40 on the K3/P3 is highly varied ...


1.  Narrow discrete carriers [that appear linked, 25-35 kHz apart] 
come and go, sometimes within seconds


2.  Broad [5-10 kHz] bands of noise, often without any harmonic 
brethren [that I can find] that come in pulses that look like 
wide-band AMTOR


3. "Rope-like" noise on the WF, with and without harmonic brethren 
that often changes in character but mainly a primary signal 
oscillating back and forth in frequency over maybe 5 kHz.


Underground utilities, but we do have a 345 kV transmission line about 
two miles away that runs from a large power plant 5 or 6 miles east to 
somewhere up in OR near the Columbia.  Sources are a mystery, but I've 
suspected harmonics of transmission line carrier-current signaling ... 
they really look like sometimes it's just idling, and then a burst of 
information.


73,

Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

Alan Bloom wrote on 6/7/2022 4:21 PM:
As part of christening my new QTH/antenna/rig here at N1AL, today I 
did the test where I recorded all off-the-air spurious signals on all 
bands and then threw the main circuit  breaker for the house and did 
the measurement again, powering the K4 from a battery.  This is to 
identify any spurs that are coming from my house so I can do further 
sleuthing to figure out what is causing them.


One spur (or set of spurs) has me mystified.  It is a series of 
harmonics, with very stable frequencies, spaced at precisely 24 kHz, 
that extend from roughly 6.6 MHz to 7.4 MHz.  Each spur consists of a 
main carrier and a secondary carrier approximately 150 Hz lower in 
frequency and approximately 8 dB lower in amplitude.  The spurs are 
all the same amplitude, around -90 dBm (S6), dropping off as you 
approach 6.6 or 7.4 MHz.  I don't see these spurs on any other band.


The spur amplitudes did not change when I turned off AC power, so it 
can't be the rig's switching power supply or any other electronic 
device in the house.  It's nothing internal to the radio because if I 
switch to a dummy antenna the spurs go away.


So it's coming in through the antenna.  The antenna is a 6-band trap 
vertical about 30 feet from the house, with the coax coming 
underground to the shack.  We're on a large lot, there is a canyon 
(i.e. no houses) behind the property, and there is a vacant lot on 
the side where the antenna is located so the nearest houses in the 
neighborhood are about 150 feet away from the antenna.


The electric utility power lines switch from overhead to underground 
at our property line, about 150 feet away from the antenna. Internet 
is via cable, which is underground also.  Both power and Internet 
enter at the far end of the main house, which is over 100 feet from 
the shack, located in a granny unit.


I believe the exact fundamental frequency is 7007.03 kHz / 292 = 
23.9967 kHz, in case that's a clue.


Anyone have any ideas of what could be causing this?

Alan N1AL






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Re: [Elecraft] [Elecraft-K4] I need a Sherlock Holmes (weird spurs on 40m)

[Alan Bloom]

Yes, the modem router and a second router in the granny unit both run on 
AC power, so they were off.  There is no wired LAN to either the 
computer or the K4 -- both connect to the Internet via Wi-Fi.


Alan N1AL


On 6/7/22 17:41, Ron wrote:

Sounds like wired LAN noise.  Did you shut down your router and any switches as 
well as any device connected to the LAN?

Ron
   N6IE
www.N6IE.com

Member:
   ARRL
  Redwood Empire DX Assn.
Northern California Contest Club
Northern California DX Foundation
 DXCC Honor Roll - 337/345
   Society of Broadcast Engineers

-Original Message-
From: elecraft...@groups.io  On Behalf Of Al N1AL
Sent: Tuesday, June 7, 2022 4:22 PM
To: Elecraft Discussion List ; elecraft...@groups.io
Subject: [Elecraft-K4] I need a Sherlock Holmes (weird spurs on 40m)

As part of christening my new QTH/antenna/rig here at N1AL, today I did the 
test where I recorded all off-the-air spurious signals on all bands and then 
threw the main circuit  breaker for the house and did the measurement again, 
powering the K4 from a battery.  This is to identify any spurs that are coming 
from my house so I can do further sleuthing to figure out what is causing them.

One spur (or set of spurs) has me mystified.  It is a series of harmonics, with 
very stable frequencies, spaced at precisely 24 kHz, that extend from roughly 
6.6 MHz to 7.4 MHz.  Each spur consists of a main carrier and a secondary 
carrier approximately 150 Hz lower in frequency and approximately 8 dB lower in 
amplitude.  The spurs are all the same amplitude, around -90 dBm (S6), dropping 
off as you approach
6.6 or 7.4 MHz.  I don't see these spurs on any other band.

The spur amplitudes did not change when I turned off AC power, so it can't be 
the rig's switching power supply or any other electronic device in the house.  
It's nothing internal to the radio because if I switch to a dummy antenna the 
spurs go away.

So it's coming in through the antenna.  The antenna is a 6-band trap vertical 
about 30 feet from the house, with the coax coming underground to the shack.  
We're on a large lot, there is a canyon (i.e. no houses) behind the property, 
and there is a vacant lot on the side where the antenna is located so the 
nearest houses in the neighborhood are about
150 feet away from the antenna.

The electric utility power lines switch from overhead to underground at our 
property line, about 150 feet away from the antenna. Internet is via cable, 
which is underground also.  Both power and Internet enter at the far end of the 
main house, which is over 100 feet from the shack, located in a granny unit.

I believe the exact fundamental frequency is 7007.03 kHz / 292 = 23.9967 kHz, 
in case that's a clue.

Anyone have any ideas of what could be causing this?

Alan N1AL



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[Elecraft] I need a Sherlock Holmes (weird spurs on 40m)

[Alan Bloom]

As part of christening my new QTH/antenna/rig here at N1AL, today I did 
the test where I recorded all off-the-air spurious signals on all bands 
and then threw the main circuit  breaker for the house and did the 
measurement again, powering the K4 from a battery.  This is to identify 
any spurs that are coming from my house so I can do further sleuthing to 
figure out what is causing them.


One spur (or set of spurs) has me mystified.  It is a series of 
harmonics, with very stable frequencies, spaced at precisely 24 kHz, 
that extend from roughly 6.6 MHz to 7.4 MHz.  Each spur consists of a 
main carrier and a secondary carrier approximately 150 Hz lower in 
frequency and approximately 8 dB lower in amplitude.  The spurs are all 
the same amplitude, around -90 dBm (S6), dropping off as you approach 
6.6 or 7.4 MHz.  I don't see these spurs on any other band.


The spur amplitudes did not change when I turned off AC power, so it 
can't be the rig's switching power supply or any other electronic device 
in the house.  It's nothing internal to the radio because if I switch to 
a dummy antenna the spurs go away.


So it's coming in through the antenna.  The antenna is a 6-band trap 
vertical about 30 feet from the house, with the coax coming underground 
to the shack.  We're on a large lot, there is a canyon (i.e. no houses) 
behind the property, and there is a vacant lot on the side where the 
antenna is located so the nearest houses in the neighborhood are about 
150 feet away from the antenna.


The electric utility power lines switch from overhead to underground at 
our property line, about 150 feet away from the antenna. Internet is via 
cable, which is underground also.  Both power and Internet enter at the 
far end of the main house, which is over 100 feet from the shack, 
located in a granny unit.


I believe the exact fundamental frequency is 7007.03 kHz / 292 = 23.9967 
kHz, in case that's a clue.


Anyone have any ideas of what could be causing this?

Alan N1AL

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Re: [Elecraft] OT: 15 meters last night

[Alan Bloom]

About 8 pm here in southern Utah I was listening to W1AW code practice 
on 10 meters.   Good strong signal - received on a ground-mounted trap 
vertical antenna.  And I could hear a bunch of 10 meter beacon stations.



Alan N1AL


On 5/26/22 17:46, Wayne Burdick wrote:

Amazing is the only word for it. I haven't heard an opening to EU like that on 
15 m at close to midnight PST for...about 11 years.

I just happened to be testing new firmware on the K4. Thought I'd wrap it up 
and get to bed. (Not. Much DX worked on CW.)

Anyone else notice?

Wayne
N6KR

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Re: [Elecraft] K4 Firmware Updating

[Alan Bloom]

Yes, a WiFi extender works for me as well.  The one I'm using is $39 on 
Amazon:


https://www.amazon.com/gp/product/B0118SPFCK/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8=1

Alan N1AL


On 4/26/22 07:01, Dave wrote:

As someone who doesn’t have a wired Ethernet connection in the shack, I can
assure anyone concerned about updating a K4 via wireless, that an ordinary
WiFi extender with an RJ45 Ethernet port works fine.

I use a Netgear AC1200 (EX6120) with a 5 metre Cat6 fully shielded patch
cable. It works fine. The extender is 30 GBP from Amazon UK.

73 Dave G4AON
K4D #286

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Re: [Elecraft] Elecraft Service

[Alan Bloom]

There is a 52 year old Drake B-line in my shack



In those days, radios were easily field-repairable.  If one quit 
working, you replaced a tube or perhaps a burned-up resistor or 
dried-out electrolytic capacitor.  Almost all the parts were standard 
devices that you could order from a parts distributor.



Component-level repair is almost a thing of the past.  For one thing, 
modern radios include microprocessors, application-specific ICs, and 
other very useful parts that unfortunately can become unobtanium once 
they become obsolete.



Another problem is that surface-mounted parts are harder to work on.  
For example, if a ball-grid array IC fails, you need highly-specialized 
equipment to remove it and install a new one.



And then there is the problem of programmable devices such as 
microprocessors and gate arrays.  Even if you replace the part, you 
still have to figure out how to program it somehow.



Modern amateur radio transceivers are marvels of technology that run 
rings around the radios of yore, but the price we pay is they are not as 
easy to repair.



Alan N1AL



On 4/21/22 14:40, K9ZTV wrote:

No radio is ever "toss and replace" if it is cared for.

There is a 52 year old Drake B-line in my shack that has never been back to 
Miamisburg, and a Hallicrafters T.O. keyer of the same vintage that has never 
revisited Chicago.

There is a 46 year old KWM-2A that has never taken a trip back to Cedar Rapids, 
and a 23 year old FT-1000D that has never taken a flight to Tokyo.

None are software upgradeable, all are obsolete.  None have fully obtainable 
parts, yet all are fully functional and occasionally on the air.

Moreover, my own 15 year old $4000 K3 has somehow survived operator miscues of 
a dozen or more Field Days and I trust it will survive those of the upcoming 
one as well.

In my experience, amateur radio equipment does not self-destruct.  They need 
our help.

Which would imply that maybe the fraternity's first obligation to a new ham is 
to inform him of those things that will harm whatever he is eager to buy.  And 
perhaps its second obligation is to remind him again when he is eager to spend 
real money.

73,

Kent  K9ZTV


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Re: [Elecraft] [POSSIBLE SPAM] Re: Cleaning solder flux

[Alan Bloom]

There are some components that can be damaged by water and/or cleaning 
detergent.  For example, you may need to re-lubricate the bearings of 
variable capacitors and other components with moving parts.


If water gets inside a power transformer it can be hard to dry it out.  
A method some use is to power up the transformer with low voltage, 
perhaps from a variable-voltage (Variac) transformer.  Make sure the 
power transformer has a big enough load to cause some self-heating 
(perhaps the filaments of the equipment that the transformer is 
powering) and leave it for a few days to dry out before applying full 
voltage.  Place the equipment in a safe spot (concrete floor) and make 
sure it is well-fused in case a short does occur.


Alan N1AL


On 1/2/2022 12:20 PM, Fred Jensen wrote:
My S-Line acquired some tropical fungus that lived in the IF cans and 
would creep out onto the chassis in fuzzy little splotches.  I found 
that a trip to the DIY car wash followed by a hair dryer worked 
wonders.  Never seemed to bother the operation or calibration of the 
RX and TX either.


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Re: [Elecraft] Cleaning solder flux

[Alan Bloom]

I believe that water-soluble flux does indeed need to be washed off to 
prevent corrosion.  That's what HP used (probably still uses) on 
production PC boards.


However, RA (rosin activated) or RMA (rosin mildly-activated) fluxes 
that are used in repair and rework (or homebrew projects) may be left in 
place.  They only need to be removed for cosmetic purposes. In fact, 
attempting to remove the flux with alcohol or another solvent can 
actually cause problems if the removal process is not complete.


Alan N1AL


On 1/2/2022 11:16 AM, Ray wrote:

I worked at a large Computer Company in Cupertino, and we used Water Soluble 
Flux,
Then washed the Boards in a Dishwasher, with Water.
Open Air Drying to keep water from Wicking into any Parts.

Ray WA6VAB  Engineering.  K3



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Re: [Elecraft] Cleaning Solder Flux, Redux

[Alan Bloom]

Kester specifically says that rosin residue removal is for cosmetic 
considerations.    Here's the exact quote:


"Rosin flux residues are non-conductive and non-corrosive. Under normal 
circumstances they do not have to be removed from a printed circuit 
assembly. Rosin residue removal would be for cosmetic considerations. In 
an environment where the working temperature of the assembly will exceed 
200°F the rosin residues will melt and become conductive, in these 
situations flux removal is required."


https://www.kester.com/knowledge-base/faq#46137-rosin-flux-removal-the-question-that-frequently-comes-up-is-do-rosin-flux-residues-need-to-be-removed

Again I recommend that you not attempt to remove the flux residue unless 
you have the technical means to ensure that all traces of it are 
completely removed.


Alan N1AL


On 1/1/2022 2:01 PM, Eric Garner wrote:

>The only reason for removing flux is purely cosmetic

That isn't accurate. Even modern no-clean fluxes can cause corrosion 
and current leakage if left in place under certain conditions If 
leakage is a concern, you can specify a surface resistivity level and 
the boards can be ultrasonic washed or double DI washed to meet that 
criteria.


Eric KI7LTT

On Sat, Jan 1, 2022, 11:16 AM Alan Bloom  wrote:

Another problem with cleaning flux is ionic contamination.  The
activator in the flux, which is necessary to get the solder to
stick, is
acidic.  As long as the flux is left alone, the ionic
contamination is
trapped in the rosin where it can do no harm.  But when you
dissolve it
with alcohol or another solvent is is spread over the surface of the
board, unless you do a VERY thorough job of cleaning it off.  That
can
cause electrical leakage between circuit nodes and potentially
corrosion.

The only reason for removing flux is purely cosmetic. When I was at
HP/Agilent the rule in production and service was that any flux
remaining on the board due to re-work or repair was just left in
place.

Alan N1AL


On 1/1/2022 3:25 AM, CUTTER DAVID via Elecraft wrote:
> Ted
> If the residue is clear, don't bother, you might create more
damage than you realise (ESD).  If the residue is brown, you've
been using the wrong solder.  If you really feel the desire for
aesthetics then you can can brush it with IPA, but beware ESD if
there are sensitive components on board.  Also beware some
components can dissolve in some cleaners, eg old style polystyrene
capacitors.
>
> 73 and HNY
> David G3UNA
>
>> On 31 December 2021 at 20:52 eda...@aya.yale.edu wrote:
>>
>>
>>
>>
>> Is there a consensus among builders of the traditional kits
(K1, K2, etc)
>> about the best way to remove solder flux from a completed
circuit board?
>> Some Internet sites recommend acetone, others say isopropyl
alcohol. A few
>> tout their own product without saying exactly what it is.  I
remember
>> reading someplace that one or the other of those will clean the
flux but
>> could also cause damage by being absorbed into components. 
Yes, I know this
>> is all purely cosmetic but if it can be done safely I'd like to
try it on
>> the next kit.  Suggestions?
>>
>>
>>
>> Thanks,
>>
>>
>>
>> Ted, KN1CBR
>>
>>
>>
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Re: [Elecraft] Cleaning Solder Flux, Redux

[Alan Bloom]

Another problem with cleaning flux is ionic contamination.  The 
activator in the flux, which is necessary to get the solder to stick, is 
acidic.  As long as the flux is left alone, the ionic contamination is 
trapped in the rosin where it can do no harm.  But when you dissolve it 
with alcohol or another solvent is is spread over the surface of the 
board, unless you do a VERY thorough job of cleaning it off.  That can 
cause electrical leakage between circuit nodes and potentially corrosion.


The only reason for removing flux is purely cosmetic.  When I was at 
HP/Agilent the rule in production and service was that any flux 
remaining on the board due to re-work or repair was just left in place.


Alan N1AL


On 1/1/2022 3:25 AM, CUTTER DAVID via Elecraft wrote:

Ted
If the residue is clear, don't bother, you might create more damage than you 
realise (ESD).  If the residue is brown, you've been using the wrong solder.  
If you really feel the desire for aesthetics then you can can brush it with 
IPA, but beware ESD if there are sensitive components on board.  Also beware 
some components can dissolve in some cleaners, eg old style polystyrene 
capacitors.

73 and HNY
David G3UNA


On 31 December 2021 at 20:52 eda...@aya.yale.edu wrote:


  


Is there a consensus among builders of the traditional kits (K1, K2, etc)
about the best way to remove solder flux from a completed circuit board?
Some Internet sites recommend acetone, others say isopropyl alcohol. A few
tout their own product without saying exactly what it is.  I remember
reading someplace that one or the other of those will clean the flux but
could also cause damage by being absorbed into components.  Yes, I know this
is all purely cosmetic but if it can be done safely I'd like to try it on
the next kit.  Suggestions?

  


Thanks,

  


Ted, KN1CBR

  


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Re: [Elecraft] “ELECRAFT NVIS field day”

[Alan Bloom]

but having a low antenna goes a long
way toward limiting the contacts you make to NVIS propagation.



I suspect you could accomplish the same result simply by reducing 
transmitter power.


A dipole 1/4 wavelength high has a nearly identical radiation pattern to 
one close to the ground.  It just has less loss.


Alan N1AL


On 12/18/2021 10:28 AM, John Harper wrote:

You might want to consider doing this within the Winter Field Day event.

That's a great suggestion.

Those are correct who say that an antenna (dipole) doesn't have to be low
to the ground to make use of NVIS - but having a low antenna goes a long
way toward limiting the contacts you make to NVIS propagation.

John AE5X
https://ae5x.blogspot.com/2021/12/nvis-my-own-brief-experience.html
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Re: [Elecraft] HELP! XFINITY SHUT OFF INTERNET DUE TO HAM ANTENNAS

[Alan Bloom]

On 10/21/2021 9:43 AM, Drew AF2Z wrote:

Dump Comcast at the soonest opportunity.


There may be more options than you realize that avoid having to deal 
with the cable company and have no potential for interference to/from 
the amateur station.


I recently bought a house here (near St. George Utah).  There is no 
cable in my neighborhood so at first it appeared that the only option 
was DSL (via the telephone line) at 3 Mbps for $50/month.


But a quick Internet search found three local companies that offer 
"Fixed Wireless" Internet service.  This is where they beam the Internet 
to you via microwave from stations on nearby mountains. Costs range from 
$40 to $200/month for 25 to 300 Mbps.


I had a similar setup back at my house in California that had no DSL or 
cable available in the neighborhood.  Once I got the antenna properly 
located it worked reliably and of course there was no QRM to/from the 
HF/2 meter ham gear.


Alan N1AL

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[Elecraft] Parts availability

[Alan Bloom]

Recently I tried to order some electronic parts for a project I am 
working on.  In the old days (like, a year ago) I would just get on the 
Digi-Key web site, order what I want, and it would arrive in the mail in 
a few days.


These days, there are a LOT of parts on the Digi-Key web site that show 
no availability.  I wanted to buy 10 standard, run-of-the-mill LM358 
op-amps in an 8-pin DIP package.  This is a 25 cent part that has been 
around for decades.  They had none in stock in that quantity, from any 
manufacturer.  I ended up ordering a couple in the old-fashioned TO-5 
metal can package for *10 bucks each*. At least they did have some of 
those in stock.


I also wanted to buy a ceramic capacitor assortment.  They listed 6 
assortments that would have worked for me, but all were out of stock.


Manufacturers with "just in time" parts ordering systems are in a world 
of hurt these days.  Fortunately I don't think Elecraft ever went down 
that path.


Alan N1AL
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Re: [Elecraft] K4 operating manual now available as both .pdf and .html

[Alan Bloom]

NOTE:  The operating manual has a black background


I can make the manual (K4 Built-In Operating Manual, rev C9.pdf) look 
the way I want on the screen (black text on a white background with 
images rendered in correct colors) in Adobe Reader by selecting:


Edit > Preferences > Accessibility

and then:

select "Replace Document Colors"
select "Use High-contrast colors"
unselect "Only change the color of black text or line art."
unselect "Change the color of line art as well as text."
select "High-contrast color combination:" = "Black text on white".

However, although it looks correct on the screen, when I print it it 
still comes out with the black background.


I'm just using the free version of Adobe Reader.  Perhaps someone with a 
paid-up version can get it to print correctly (print to a printer or 
print to another PDF file).


Alan N1AL




On 8/5/2021 4:08 PM, Wayne Burdick wrote:

Rev. C9 of the K4 operating manual can be found here:

   https://elecraft.com/pages/k4-high-performance-direct-sampling-sdr-manuals

In addition to the .html version, we're now providing a .pdf, as requested.

NOTE:  The operating manual has a black background, consistent with the color 
scheme used for all text boxes on the K4's LCD. Obviously, printing a hard copy 
wouldn't be advised, as you would consume the entire ink supply at your local 
Office Depot. It cannot be easily converted to a white background given all of 
the text styles used, so this isn't likely to happen in the short term.

73,
Wayne
N6KR



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Re: [Elecraft] Broke my K2 :(

[Alan Bloom]

Don is exactly right about this.  When I was at HP/Agilent, the company 
directive was generally not to try to clean the rosin with alcohol.  
(Rosin-core solder was used only in rework.)  The rosin contains an acid 
to help with the soldering, but the acid is locked up inside the rosin 
where it does no harm.  Once you dissolve the rosin with the alcohol it 
spreads out and can cause leakage paths between connections.  Just leave 
the rosin there; it does no harm


HP did clean production boards after going through the wave solder 
machine.  But that used a water-soluble flux and the cleaning process 
was thorough enough to completely remove all traces of flux.  That's 
basically not possible using alcohol and cotton swabs on rosin.


Alan N1AL


On 7/14/2021 5:20 PM, Don Wilhelm wrote:
When I have cleaned boards with IPA or other cleaners, I apply the IPA 
only in a small spot with a q-tip and then blot it with a paper towel 
to help dry it - do not flood the board.
I generally do not recommend cleaning boards, solder flux is 
non-conductive and will normally not cause a problem.
I only clean when the solder flux residue is really nasty as might 
occur with Kester 44 solder.
Use of a solder with a mildly reactive flux (Kester 385) will reduce 
the need for cleaning the board - there is almost no residue.


If you do choose to clean the board, make sure your cleaning work is 
complete.  While solder flux is non-conductive, the flux plus the 
cleaner may be conductive leading to resistive leakage paths. If you 
can see any white stuff on the board, you have not done a complete job.


73,
Don W3FPR

On 7/14/2021 6:41 PM, Peter Eijlander (PA0PJE) wrote:

Yes Jerry, isopropyl alcohol does this!
I once cleaned a working print of a GPS receiver with isopropyl 
alcohol and it stopped working. Letting it be and trying it again 
next day turned out it worked perfectly again.


 From then on I leave a PCB to rest after cleaning to have the IPA 
dry out completely...


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Re: [Elecraft] Question about antenna matching

[Alan Bloom]

The Drake tuners used a Pi-L circuit topology in which the circulating 
current in the inductor is independent of the load impedance.  Assuming 
almost all the loss is in the inductor, that means that the loss is 
independent of the load impedance.


(Another advantage of that topology is you get good harmonic suppression 
for all load impedances.)


So when I was designing the Drake MN-2700 I just measured the loss into 
a 50 ohm load and made sure it was less than the 0.5 dB spec with some 
margin.  That won't work when using most topologies (such as the L 
networks used in the Elecraft tuners) because the loss does change 
drastically depending on the load impedance.  For those, you can use two 
identical tuners back to back, both adjusted for the same load 
impedance.  The loss for each tuner is approximately half the measured 
loss.  (I think I did do a few tests like that on the MN-2700 just as a 
sanity check.)


I found that the hardest band to get to meet all specs (5:1 SWR, 0.5 dB 
loss, 1000W average, 2000W PEP) was 160 meters.  That's partly because 
it is hard to get a high-inductance, super high-Q coil small enough to 
fit in the cabinet and partly because of the large capacitances 
required.  (The MN-2700 has 3-position switches to add fixed capacitance 
to each tuning capacitor.)


To measure the matching capability at different phase angles, I just 
connected a 50-ohm load to the input and an HP impedance analyzer to the 
output.  By adjusting each tuning capacitor throughout its range and 
plotting the results on a Smith chart you can see the (complex conjugate 
of the) matching range.  Actually the output impedance of the tuner and 
the antenna impedance it matches are not exactly conjugates, but are 
close as long as the tuner insertion loss is low.


As suggested by Dave, I chose typical Q values of 100 for the inductor


The coils in the MN-2700 have much higher Q than that.  To such an 
extent that it was difficult to get accurate readings on an HP Q-meter.  
But by tightening the connecting bolts down as hard as possible and 
making sure there were no absorbing objects (like human hands) in the 
near field of the inductor I was getting values in the 700-800 range on 
some bands as I recall.  (These were all air-wound solenoidal inductors.)


Alan N1AL


On 7/13/2021 10:32 AM, Al Lorona wrote:

Thanks to Al N1AL, Jack W6FB, and Dave AB7E for great information that helped 
me a lot.

I'm in the circuit simulation business, after all, and I confess that I was 
just being lazy, so I ran some simulations that confirmed what Dave, in 
particular, had said.

As suggested by Dave, I chose typical Q values of 100 for the inductor and 1000 
for the capacitor. Then I simulated as many points as I could on the entire 
Smith Chart to see 1/ if the tuner could tune each point to 50 ohms, and 2/ 
what the power loss was in the tuner at each of those points. Then, I 
discovered that K6JCA had already done this on his excellent blog at:  
https://k6jca.blogspot.com/2015/03/notes-on-antenna-tuners-l-network-and.html . 
The guy is totally professional and exhaustive in his discussions. I really 
admire his work.

Anyway, it turns out you can make a graph of power lost in the tuner versus 
phase angle of the load. As you might suspect, 'easy' loads of 5 or 500 ohms 
resistive (SWR = 10:1) don't tax a tuner as much as reactive loads do. In fact, 
they're near (but interestingly, not at) the areas of *minimum* power loss.

Whenever an antenna tuner is reviewed in QST, resistive mismatched loads are 
usually used. I'd like to see tuners tested with reactive loads, but the number 
of loads required to do this from 160 to 10 meters would be enormous. I see why 
resistive loads are preferred, because you can re-use the loads on every band.

I'm frustrated by imprecise statements like, "This tuner will tune an 8:1 
mismatch." What does that mean? There has to be a better way for manufacturers to 
spec the exact impedance ranges that their tuners will tune. I like the method that I 
used, which shades a Smith Chart in color based on the two criteria I listed above. One 
picture would tell you all about a tuner's effectiveness. No real tuner can tune the 
entire Smith Chart, but the more of the chart that is covered, the better the tuner. And 
if you can shade the areas of higher tuner loss in red, then that would also tell you an 
important piece of information. (However, to generate such a plot through measurement 
you'd probably need a very expensive load-pull setup, which is a totally separate 
discussion.)

For the L-network I simulated, a particularly difficult 10:1 load was near the 7 - 
 j30 ohm point, which is toward the bottom edge of the Smith Chart at a phase 
angle of 282 degrees (or -77 degrees), and a similar point near the top edge. The 
lower impedances with capacitive reactance were definitely the most difficult 
(using power loss as the measure of 'difficulty') for the tuner to handle, which 

Re: [Elecraft] Question about antenna matching

[Alan Bloom]

I can't speak directly about Elecraft tuners, but I did design an 
antenna tuner when I was at Drake many years ago.


We specified the Drake MN-2700 at 5:1 SWR.  I made sure it would match 
that SWR at all phase angles on all specified bands.


Typically the low-impedance end tends to be the hardest to match, at 
least on the low bands.  So 50/5 = 10 ohms resistive is harder to match 
than 50*5 = 250 ohms resistive even though the SWR is 5:1 in both 
cases.  That's because the low impedances need larger tuning 
capacitors.  The Drake tuner would typically match well above 5:1 into a 
high impedance but only barely meet spec into a low impedance.  I 
suspect the Elecraft tuners are similar.


Alan N1AL


On 7/11/2021 12:58 PM, Al Lorona wrote:

This question is about how manufacturers spec the matching range of their 
antenna tuners.

If an antenna system presents an impedance of 5 + j0 ohms to the antenna tuner, 
that's an SWR = 10 to 1.

But, an antenna impedance of 50 - j143 ohms is also SWR = 10. So is 110 - j200 
ohms.

When a manufacturer like Elecraft says, "Our antenna tuner can match a 10:1 
mismatch," does that mean the tuner can match the first case above, the second case, 
the third case, or all three?

I guess what I'm asking is, are all of the impedances above equally difficult 
for the same tuner to match? Or is one 'harder' than the others? It would 
depend on the values of the L and C in the tuner, wouldn't it? Which implies 
that certain 10:1 mismatches are not tunable?

Thanks,

Al  W6LX/4

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Re: [Elecraft] Funny K4 Story

[Alan Bloom]

I believe the SWR meter in the transceiver is at the input of the 
internal tuner, not the output.  Since it always reads close to 1:1 when 
the tuner is engaged you may not notice if the antenna has a high SWR.


Alan N1AL


On 5/16/2021 5:10 PM, Wayne Burdick wrote:

The K4 shows all four TX bar graphs simultaneously:  power, SWR, ALC, and 
compression. In addition you can select numeric display of power, SWR, supply 
voltage and current drain for the status area, which defaults to date/time.

Wayne
N6KR


elecraft.com


On May 16, 2021, at 12:18 PM, Ray  wrote:

My K3 has a SWR display next to the RF Power meter in the Display.
So it Sounds like the K4 Does Not have that type of Display ?

WA6VAB  K3



On May 16, 2021, at 11:04 AM, Tom Doligalski via Elecraft 
 wrote:

...
I normally would have noticed the change in SWR, and realized that I had an 
antenna problem. But, of course, I had tuned the K4 for the first time on 80M 
when I received it!

A learning moment (operator error?). Gonna try to check the antennas out a bit 
more frequently!

73, Tom W4KX



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Re: [Elecraft] P3 Newbie needs help.

[Alan Bloom]

If the frequency display at the top center of the P3 screen is reading 
zero, then that implies there is something wrong with the RS-232 
connection between the K3 and the P3.  Recheck the connections on page 5 
of the P3 manual:


https://ftp.elecraft.com/P3/Manuals%20Downloads/E740152%20P3%20Owner's%20man%20Rev%20H1.pdf

The two-headed cable should plug into the two RS-232 connectors on the 
P3 in the order shown.  Make sure all the connectors are well-seated.


Alan N1AL


On 3/31/2021 2:49 PM, Richard Hayman wrote:

Just picked up K3s and P3 combo. The K3s had just been returned from Elecraft 
service and seems to be working perfectly. I am replacing my old K3.

Anyway, in my rush to set everything up, I can’t figure out why I have no 
frequency display on the P3. Using USB connection to communicate to the both 
the P3 and K3s using the firmware utilities. All appears normal. So I assume 
RS-232 between the K3s and P3 is fully functional.

Gotta be something simple. Right?

73, Dick, WN3R
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Re: [Elecraft] Where are the K4 reviews?

[Alan Bloom]

Best Buy has been totally out of laser printers for months.

Alan N1AL


On 3/31/2021 12:16 PM, Walter Underwood wrote:

Just not true. The Ford F-150 production is limited by parts availability. In 
November, our order for a new fridge was canceled and the model is still not 
available. If huge industries like autos and appliances can’t get parts 
sourced, little guys like Elecraft have to wait or redesign.

https://www.nbcnews.com/business/autos/chips-seating-foam-plastics-parts-shortages-continue-cripple-auto-industry-n1261773



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Re: [Elecraft] PX3 Fuse Issue

[Alan Bloom]

The PX3 should draw no more than about 200 mA from the 12V supply.

When power is first applied, there will be some inrush current due to 
the filter capacitors but I'm surprised that's enough to blow a 1A fuse.


Is it a fast-blow type fuse?  Perhaps a slow-blow type would solve the 
problem.


Alan N1AL


On 3/23/2021 3:37 PM, Jim Borowski wrote:

My PX3 Is fused with a 1amp ATC fuse once in a while the fuse blows. I believe 
the fuse blows when the power is first turned on. What does Elecraft 
recommends? Nothing else is connected to this fused line except the PX3. What 
does Elecraft recomends?Jim K9TFSent from my T-Mobile 4G LTE Device
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Re: [Elecraft] Are external tuners really needed with Chamaeleon antennas?

[Alan Bloom]

On 3/23/2021 11:51 AM, Jim Rhodes wrote:

I am often amazed at how well my tuners match some really outlandish antennas.


My KX2 loads up the aluminum rain gutter outside my window just fine on 
80 through 10 meters.  (I do have 1/4-wave counterpoise wires for 40, 20 
and 10 meters.)


Alan N1AL

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Re: [Elecraft] PSK31 with a KX2

[Alan Bloom]

I just tried out DigiPan with my KX2 for the first time earlier today.  
At first I thought it wasn't working because I couldn't decode any 
signals on PSK31.  Then I happened to stumble on a W1AW bulletin on 
RTTY.  Then they switched over to PSK31 and it decoded perfectly.


I guess the answer is that a lot of the signals on the air that sound 
like PSK31 are actually something else.


By the way, PSK31 is symmetrical in frequency so it doesn't matter 
whether you select LSB or USB.   That's why the Reverse function in 
DigiPan is disabled for PSK31.


When W1AW first switched from RTTY to PSK31, the KX2 was still in FSK 
mode with the narrow filter.  It decoded the PSK31 just fine. Then I 
switched to LSB and it continued to decode perfectly.


Alan N1AL


On 3/9/2021 6:11 PM, Bob Liesen wrote:

All,
   Pulling my hair out here.  I have been trying to get my KX2 to work on
PSK31.  After many attempts I got it working perfectly with DigiPan, but
I'm not sure how.   Then something happened that I have found is a problem
for me with this radio.  I must have turned a knob, hit a key or some such
thing as it stopped decoding.  I find the knobs and buttons are too close
to one another for these old eyes and fingers.
   I am using DATA A mode, I have the BW at 4kHz and center freq of 1.5  AGC
is off, RF gain is 0dB.  NB and NR is off.  I suspected I might have
screwed up the USB/LSB setting somehow, but HamScope has a "reverse"
function which does not help.
  Is there anyone who could walk me through the settings that might be
screwing this up?
Tnx es 73
Bob  WB0POQ



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Re: [Elecraft] Buyer Beware ...

[Alan Bloom]

This is nothing new.  Over 40 years ago I sold a Drake 4-line to a guy 
who saw my ad in QST.  The rig was in good operating condition, but he 
decided to send it in to Drake for a complete overhaul/tuneup, new 
tubes, etc. and subtracted the cost from what he sent me.  Basically he 
got a new radio for the cost of a used one.


That's actually the only bad experience I have had buying/selling ham 
gear.  Most hams are pretty honest.


Alan N1AL


On 2/28/2021 10:27 AM, j...@kk9a.com wrote:

... The ham classified sites also have scammers
familiar with our hobby so you really have to be careful these days.




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Re: [Elecraft] K3 assembly issue

[Alan Bloom]

Unassembled Heathkits have sold for amazing amounts of money.  (I use 
the past tense because I doubt there any of those treasures left these 
days.)


I have even heard of people "making" an unassembled kit by  buying a 
built one, taking it apart, unsoldering all the components, and 
replacing the soldered parts with new ones.  Apparently it is 
financially worthwhile to do that.   :=)


Alan N1AL


On 2/14/2021 4:20 PM, John Oppenheimer wrote:

Hi Adrian, welcome to the hobby and to the Elecraft list,

Wow, that's quite a collector's item! I'd consider asking Elecraft what
they'd charge to assemble and align for you.

John KN5L

On 2/14/21 3:32 PM, KJ7SOY wrote:

Hi everyone! I’m new to the list and to Elecraft radios and HAM in general. 
Thanks for bearing with me while I learn!

I picked up an unassembled K3 at an auction three weeks ago. It’s been sitting 
in a box with most of the boards sealed in their anti-static bags since 2009. 
I’ve hit a snag and I’m hoping someone here can help.



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Re: [Elecraft] P3 span changing

[Alan Bloom]

If you return to a band but at a different K3 VFO frequency, the new 
frequency may be outside the P3's span.  If that happens, the P3 will 
re-tune using an algorithm determined by the MENU > FixMode setting.


If you want to be sure the P3 frequency doesn't change you can set 
FixMode to "Static".  Then the P3 frequency range will not change even 
if the K3 VFO frequency is out of range.


It may be that some logging programs do not retain the old frequency 
upon a band change.  Even if the frequency is "wrong" only for an 
instant, that would be enough to confuse the P3 if not in "Static" mode.


It would be interesting to see what N1MM and other logging programs are 
sending to the P3/K3 on band changes.  There is a little-known serial 
debug monitor in the P3 that shows the traffic on the two RS-232 ports.  
You activate the function by simultaneously holding the DISPLAY/AVERAGE 
and FN1/FN5 buttons.  The P3 screen changes to show RS-232 traffic 
color-coded to show on which port and in which direction the traffic is 
going.


The data can fly by awfully fast when using a logging program.  You can 
freeze the screen immediately after a band change by tapping the FN2 
key.  Tap it again to unfreeze the screen.  If you want to show more 
data you can choose a smaller font size with the MENU > Font feature.


I'm pretty sure that feature still exists in current P3 code.  I can't 
check this myself since all my ham equipment was recently lost in a fire.


Alan N1AL


On 2/8/2021 4:05 PM, Jim McDonald wrote:

I use the Fixed Tune Mode too but the center frequency sometimes isn't 
remembered when returning to a previously-used band.  If it makes any 
difference, I'm usually using N1MM+ (often with Win4K3Suite) to control the 
radio.

73,  Jim N7US

-Original Message-
From: elecraft-boun...@mailman.qth.net  On 
Behalf Of Fred Jensen
Sent: Monday, February 8, 2021 16:45
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] P3 span changing

Don't understand your "follow option" question.  I run mine in Fixed Tune Mode 
which holds the span [i.e. edge frequencies] constant and the two VFO's show up as two 
vertical cursors in the spectrum display.  The cursors move as I tune, and when I go 
beyond the edge, the span shifts by the amount I've set in the menu ... I use a full 
span.  In the Tracking Mode, your receive frequency is always centered and the spectrum 
moves past it as you tune.

73,

Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

On 2/8/2021 2:34 PM, Dave Cole wrote:

How does one set the follow option, I just looked through the menu of
the P3, and don't see it.

73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist, RFI
ARRL Asst. Director, NW Division, Technical Resources

On 2/8/21 12:39 PM, Fred Jensen wrote:

Yes, it has been discussed, and yes, that is the case.  It seems to
be most prevalent when returning to a band after moving off for a Q,
such as in NAQP's when the return is being commanded via CAT command.
In fairness to the Elecraft developers, it /*appears*/ that it is
attempting to put the frequency you are returning into the center-ish
part of the display which is not totally unreasonable.

73,

Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

On 2/7/2021 12:28 PM, Jim McDonald wrote:

I know this has been asked before but I don't remember the answer.
Isn't the P3 supposed to remember the span and center frequency from
band to band?  It seems to change center frequency even if the band
hasn't changed, but that may not be the case.

73,  Jim N7US


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Re: [Elecraft] Efficiency of MFJ remotely-tuned loop antennas

[Alan Bloom]

I love to see people doing serious homebrew.  Bravo!

I wonder if the SWR runaway at 150W could be due to the PVC pipe used as 
the insulator for the variable capacitor?  PVC is quite lossy at RF.  
Perhaps when it gets hot it detunes the capacitor.  It would be easy to 
check by simply feeling the cap to see if it gets warm.


Alan N1AL


On 1/19/2021 5:39 PM, Andy Durbin wrote:

"although I saw a design not long ago that used two coaxial copper pipes with a PVC 
pipe as the insulator.  The inside conductor was mounted to a long threaded rod moving it 
in and out of the outer conductor."

Not my original idea but that's what I have on my loop (PEX insulator not PVC). 
 Works fine up to 100 W on 30 m but has SWR runaway at 150 W.   Capacitor is 
driven by a geared DC motor and is tuned from the shack.  Home brew is far more 
fun than buying commercial.

I'll post a link to a presentation if there is any interest.

Andy, k3wyc
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Re: [Elecraft] Efficiency of MFJ remotely-tuned loop antennas

[Alan Bloom]

I've been convinced that AEA's specification of 72% efficiency for the 
Isoloop at 14 MHz is too high, certainly too high for the MFJ antennas.  
So I re-did the calculations using the 59% efficiency figure calculated 
below.  The new results can be downloaded here:


https://www.dropbox.com/s/ve1v49b3gjvmt64/MFJ-1786-1788_2.pdf?dl=0

If you don't want to download the (1-page) document with the pretty 
graph, here's a synopsis of the results:


Freq      Eff. Gain with respect to a 1/2-wavelength dipole
MHz      dB  dBd
7.0         -9.5    -9.9
10.1       -5.1    -5.5
14.0       -2.3    -2.7
18.068   -1.1    -1.5
21.0   -0.7    -1.1
24.89 -0.4    -.8
28.0   -0.26  -0.65

My basic conclusions still stand.  With almost minus 10 dBd of gain on 7 
MHz, the 40 meter coverage of the MFJ-1788 doesn't seem very useful.  
That is confirmed by some of the reviews I have seen.  I think you'd get 
better results by just loading up the coax feedline as a random-wire 
antenna with a tuner.


The 10 MHz performance is a little better.  Good enough to at least 
allow you to get on the 30 meter band.


On the higher bands, the gain is within less than 3 dB of a full-sized 
dipole, which seems a useful trade-off for its small size and wide-band 
continuous coverage.


Disclaimer:  Again, I have never seen one of these things so this is all 
based on theory and on the many reviews I have read.  Even if my figures 
are off a bit, at least this gives an idea of the relative performance 
on the various bands.


Alan N1AL



On 1/18/2021 5:38 PM, Alan Bloom wrote:

Well let's see...

Radiation resistance of a small loop is 31,171 * (Area / wavelength^2)^2

For a loop with a 91cm diameter at 14 MHz, I believe that comes out to 
0.064 ohms.


Assuming the loss is due to the RF resistance of the loop:

From the internet I get the volume resistivity and skin depth for 6063 
aluminum is 0.03 microohms-meter and 23.3 micrometers respectively, so 
the surface resistivity is 0.03/23.3 = 0.0013 ohms per square.  The 
outside circumference of the tubing is PI * 1.05" = 3.3" and the loop 
length is PI * 36" = 113" so the loss resistance is .0013 * 113/3.3 = 
0.045 ohms.


So I calculate an efficiency of 0.064 / (0.064 + 0.045) = 59%

So worse than AEA claimed, but in the ballpark.

Alan N1AL




On 1/18/2021 3:39 PM, Wayne Burdick wrote:

Hi Alan,

72% sounds a bit high. Is this number based on loop size alone ("in 
theory")? Or are they taking conductor geometry and other losses into 
account?


Wayne
N6KR



On Jan 18, 2021, at 2:05 PM, Alan Bloom  wrote:

MFJ makes a pair of small, remotely-tuned loop antennas, the 
MFJ-1786 that covers 10-30 MHz and the MFJ-1788 that covers 7 to 21+ 
MHz.  As far as I can tell, the two antennas are identical except 
for the size of the tuning capacitor.  Each consists of a 3 foot (91 
cm) diameter loop made of aluminum tubing and a plastic housing that 
contains the tuning capacitor, motor, and coupling loop.  No control 
cable is required since the control voltage is sent from the control 
box in the shack to the motor in the antenna via the coaxial cable.


Before I purchase one of these I wanted to get an idea of the 
efficiency of such a small loop.  MFJ is silent on the subject so I 
did my own calculations.  The calculations and results are on a 
1-page document that I uploaded to Dropbox and can be downloaded here:


https://www.dropbox.com/s/l8mv67cjrck2ssn/MFJ-1786-1788.pdf?dl=0

My calculations are based on the assumption that the efficiency of 
the MFJ antennas is similar to the (no longer manufactured) AEA 
Isoloop (my reasoning for that is in the document) and that AEA's 
specification of 72% efficiency at 14 MHz is correct.  From that 
number I can calculate the efficiency and gain on all the other bands.


If you don't want to download the document, here is a summary of the 
results:


Freq  Eff  Gain with respect to a half-wave dipole
MHz  dB  dBd
7.0    -7.3    -7.7
10.1      -3.5    -3.9
14.0      -1.4    -1.8
18.068  -0.6    -1.0
21.0      -0.4    -0.8
24.89    -0.2    -0.6
28.0  -0.15  -0.5

I'd be interested in any comments people may have on the accuracy of
my assumptions and calculations in the document.

Alan N1AL


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Re: [Elecraft] Efficiency of MFJ remotely-tuned loop antennas

[Alan Bloom]

> That doesn't sound like they are welded, and given the cost 
difference for welded air variables I doubt MFJ used them.


As I said, I don't have one so I can't say for sure.  I got my 
information from the MFJ web site:  "All welded construction, no 
mechanical joints, welded butterfly capacitor with no rotating contacts 
... Each plate in MFJ's tuning capacitor is welded for low loss and 
polished to prevent high voltage arcing, welded to the radiator ...".  
https://mfjenterprises.com/products/mfj-1786


Also, for what it's worth, some of the reviews on eham.com and qrz.com 
mention that it has a welded tuning capacitor.


I got the impression that one reason people often receive units with 
bent capacitor plates is that they got bent in the welding process.


It would be interesting to look at one and see what they actually mean 
by "welded".


Alan N1AL



On 1/18/2021 10:10 PM, David Gilbert wrote:


According to another ham who recently posted here, he had to "tighten" 
the plates on the MFJ capacitor to get it to work properly.  That 
doesn't sound like they are welded, and given the cost difference for 
welded air variables I doubt MFJ used them.


I sincerely doubt that an actual practical small loop is only down 3 
dB from a full size antenna.  That makes no sense to me at all. If 
that were the case everyone would be using one, because they are not 
that difficult to make ... at least for manually tuned ones.


But you seem determined to believe differently, and it's not my place 
to convince you otherwise.  You asked for inputs and I have made 
mine.  Hopefully you are right and I am wrong.


73,
Dave   AB7E



On 1/18/2021 9:54 PM, Alan Bloom wrote:
> There is a reason why top quality variable capacitors often use 
welded plates.


I believe they do weld the capacitor plates and also weld the loop to 
the capacitor.  (I don't have one, but that's what I've read.)


> Yours is a limited theoretical analysis ... not a practical one.

A number of reviews I have read (including the QST review of August 
1994) have reported comparable performance to full-sized wire 
antennas located on the same site.  If the loop is down by, say, 3 
dB, that's only half an S unit, which would hardly  be noticeable in 
the QSB of a typical amateur band.



As I see it, the advantages of the MFJ-1786 10-30 MHz loop are:

- Continuous coverage on 6 amateur bands.  A convenient way to cover 
all the WARC bands.

- Small and light.
- Omni-directional (when mounted horizontally)  so does not need a 
rotor.

- No control cable required - control voltage is fed through the coax.
- Narrow bandwidth provides excellent RF selectivity.  Might be good 
on Field Day to reduce inter-station QRM.
- Users have reported lower receiver noise compared to wire 
antennas.  No doubt that is because the isolated pickup loop prevents 
feedline radiation/pickup.


And the disadvantages:

- Expensive ($500 list price)
- Less gain than a simple dipole (although you would theoretically 
need 6 of them).

- Fiddly to tune.  If you QSY too far you have to re-tune.
- MFJ quality control leaves something to be desired.  (You may have 
to open it up when you get it and  make minor repairs.)
- You have to pay attention to the problem of entry of water and/or 
bugs into the housing.
- The controller can be damaged by a DC short in the coax e.g. from 
an shorting-type antenna switch.  (I don't understand why MFJ didn't 
include a fuse or some other way to protect the controller.)


I probably wouldn't buy the 7-21 MHz MFJ-1788 because of the poor 
efficiency at 7 MHz.  I think you'd have a better signal just using 
the coax as a random end-fed wire (with a tuner).


Alan N1AL


On 1/18/2021 8:17 PM, David Gilbert wrote:


You are neglecting the losses in various connections in the system 
... including possibly the construction of the capacitor itself. I 
don't believe that they are insignificant.  There is a reason why 
top quality variable capacitors often use welded plates.


I would also guess that contact resistance is worse for dissimilar 
materials, such as a copper wire to an aluminum tube.


Yours is a limited theoretical analysis ... not a practical one.

Dave   AB7E



On 1/18/2021 5:38 PM, Alan Bloom wrote:

Well let's see...

Radiation resistance of a small loop is 31,171 * (Area / 
wavelength^2)^2


For a loop with a 91cm diameter at 14 MHz, I believe that comes out 
to 0.064 ohms.


Assuming the loss is due to the RF resistance of the loop:

From the internet I get the volume resistivity and skin depth for 
6063 aluminum is 0.03 microohms-meter and 23.3 micrometers 
respectively, so the surface resistivity is 0.03/23.3 = 0.0013 ohms 
per square.  The outside circumference of the tubing is PI * 1.05" 
= 3.3" and the loop length is PI * 36" = 113" so the loss 
resistance is .0013 * 113/3.3 = 0.045 ohms.


So I calculate an efficiency of 0.064 / (0.064 + 0.045) = 59%

So worse

Re: [Elecraft] Efficiency of MFJ remotely-tuned loop antennas

[Alan Bloom]

> There is a reason why top quality variable capacitors often use 
welded plates.


I believe they do weld the capacitor plates and also weld the loop to 
the capacitor.  (I don't have one, but that's what I've read.)


> Yours is a limited theoretical analysis ... not a practical one.

A number of reviews I have read (including the QST review of August 
1994) have reported comparable performance to full-sized wire antennas 
located on the same site.  If the loop is down by, say, 3 dB, that's 
only half an S unit, which would hardly  be noticeable in the QSB of a 
typical amateur band.



As I see it, the advantages of the MFJ-1786 10-30 MHz loop are:

- Continuous coverage on 6 amateur bands.  A convenient way to cover all 
the WARC bands.

- Small and light.
- Omni-directional (when mounted horizontally)  so does not need a rotor.
- No control cable required - control voltage is fed through the coax.
- Narrow bandwidth provides excellent RF selectivity.  Might be good on 
Field Day to reduce inter-station QRM.
- Users have reported lower receiver noise compared to wire antennas.  
No doubt that is because the isolated pickup loop prevents feedline 
radiation/pickup.


And the disadvantages:

- Expensive ($500 list price)
- Less gain than a simple dipole (although you would theoretically need 
6 of them).

- Fiddly to tune.  If you QSY too far you have to re-tune.
- MFJ quality control leaves something to be desired.  (You may have to 
open it up when you get it and  make minor repairs.)
- You have to pay attention to the problem of entry of water and/or bugs 
into the housing.
- The controller can be damaged by a DC short in the coax e.g. from an 
shorting-type antenna switch.  (I don't understand why MFJ didn't 
include a fuse or some other way to protect the controller.)


I probably wouldn't buy the 7-21 MHz MFJ-1788 because of the poor 
efficiency at 7 MHz.  I think you'd have a better signal just using the 
coax as a random end-fed wire (with a tuner).


Alan N1AL


On 1/18/2021 8:17 PM, David Gilbert wrote:


You are neglecting the losses in various connections in the system ... 
including possibly the construction of the capacitor itself. I don't 
believe that they are insignificant.  There is a reason why top 
quality variable capacitors often use welded plates.


I would also guess that contact resistance is worse for dissimilar 
materials, such as a copper wire to an aluminum tube.


Yours is a limited theoretical analysis ... not a practical one.

Dave   AB7E



On 1/18/2021 5:38 PM, Alan Bloom wrote:

Well let's see...

Radiation resistance of a small loop is 31,171 * (Area / wavelength^2)^2

For a loop with a 91cm diameter at 14 MHz, I believe that comes out 
to 0.064 ohms.


Assuming the loss is due to the RF resistance of the loop:

From the internet I get the volume resistivity and skin depth for 
6063 aluminum is 0.03 microohms-meter and 23.3 micrometers 
respectively, so the surface resistivity is 0.03/23.3 = 0.0013 ohms 
per square.  The outside circumference of the tubing is PI * 1.05" = 
3.3" and the loop length is PI * 36" = 113" so the loss resistance is 
.0013 * 113/3.3 = 0.045 ohms.


So I calculate an efficiency of 0.064 / (0.064 + 0.045) = 59%

So worse than AEA claimed, but in the ballpark.

Alan N1AL




On 1/18/2021 3:39 PM, Wayne Burdick wrote:

Hi Alan,

72% sounds a bit high. Is this number based on loop size alone ("in 
theory")? Or are they taking conductor geometry and other losses 
into account?


Wayne
N6KR



On Jan 18, 2021, at 2:05 PM, Alan Bloom  wrote:

MFJ makes a pair of small, remotely-tuned loop antennas, the 
MFJ-1786 that covers 10-30 MHz and the MFJ-1788 that covers 7 to 
21+ MHz.  As far as I can tell, the two antennas are identical 
except for the size of the tuning capacitor.  Each consists of a 3 
foot (91 cm) diameter loop made of aluminum tubing and a plastic 
housing that contains the tuning capacitor, motor, and coupling 
loop.  No control cable is required since the control voltage is 
sent from the control box in the shack to the motor in the antenna 
via the coaxial cable.


Before I purchase one of these I wanted to get an idea of the 
efficiency of such a small loop.  MFJ is silent on the subject so I 
did my own calculations.  The calculations and results are on a 
1-page document that I uploaded to Dropbox and can be downloaded here:


https://www.dropbox.com/s/l8mv67cjrck2ssn/MFJ-1786-1788.pdf?dl=0

My calculations are based on the assumption that the efficiency of 
the MFJ antennas is similar to the (no longer manufactured) AEA 
Isoloop (my reasoning for that is in the document) and that AEA's 
specification of 72% efficiency at 14 MHz is correct.  From that 
number I can calculate the efficiency and gain on all the other bands.


If you don't want to download the document, here is a summary of 
the results:


Freq    Eff    Gain with respect to a half-wave dipole
MHz    dB    dBd
7.0    -7.3    -7

Re: [Elecraft] Efficiency of MFJ remotely-tuned loop antennas

[Alan Bloom]

Well let's see...

Radiation resistance of a small loop is 31,171 * (Area / wavelength^2)^2

For a loop with a 91cm diameter at 14 MHz, I believe that comes out to 
0.064 ohms.


Assuming the loss is due to the RF resistance of the loop:

From the internet I get the volume resistivity and skin depth for 6063 
aluminum is 0.03 microohms-meter and 23.3 micrometers respectively, so 
the surface resistivity is 0.03/23.3 = 0.0013 ohms per square.  The 
outside circumference of the tubing is PI * 1.05" = 3.3" and the loop 
length is PI * 36" = 113" so the loss resistance is .0013 * 113/3.3 = 
0.045 ohms.


So I calculate an efficiency of 0.064 / (0.064 + 0.045) = 59%

So worse than AEA claimed, but in the ballpark.

Alan N1AL




On 1/18/2021 3:39 PM, Wayne Burdick wrote:

Hi Alan,

72% sounds a bit high. Is this number based on loop size alone ("in theory")? 
Or are they taking conductor geometry and other losses into account?

Wayne
N6KR



On Jan 18, 2021, at 2:05 PM, Alan Bloom  wrote:

MFJ makes a pair of small, remotely-tuned loop antennas, the MFJ-1786 that 
covers 10-30 MHz and the MFJ-1788 that covers 7 to 21+ MHz.  As far as I can 
tell, the two antennas are identical except for the size of the tuning 
capacitor.  Each consists of a 3 foot (91 cm) diameter loop made of aluminum 
tubing and a plastic housing that contains the tuning capacitor, motor, and 
coupling loop.  No control cable is required since the control voltage is sent 
from the control box in the shack to the motor in the antenna via the coaxial 
cable.

Before I purchase one of these I wanted to get an idea of the efficiency of 
such a small loop.  MFJ is silent on the subject so I did my own calculations.  
The calculations and results are on a 1-page document that I uploaded to 
Dropbox and can be downloaded here:

https://www.dropbox.com/s/l8mv67cjrck2ssn/MFJ-1786-1788.pdf?dl=0

My calculations are based on the assumption that the efficiency of the MFJ 
antennas is similar to the (no longer manufactured) AEA Isoloop (my reasoning 
for that is in the document) and that AEA's specification of 72% efficiency at 
14 MHz is correct.  From that number I can calculate the efficiency and gain on 
all the other bands.

If you don't want to download the document, here is a summary of the results:

FreqEff Gain with respect to a half-wave dipole
MHz dB  dBd
7.0 -7.3-7.7
10.1-3.5-3.9
14.0-1.4-1.8
18.068  -0.6-1.0
21.0-0.4-0.8
24.89   -0.2-0.6
28.0-0.15   -0.5

I'd be interested in any comments people may have on the accuracy of
my assumptions and calculations in the document.

Alan N1AL
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[Elecraft] Efficiency of MFJ remotely-tuned loop antennas

[Alan Bloom]

MFJ makes a pair of small, remotely-tuned loop antennas, the MFJ-1786 
that covers 10-30 MHz and the MFJ-1788 that covers 7 to 21+ MHz.  As far 
as I can tell, the two antennas are identical except for the size of the 
tuning capacitor.  Each consists of a 3 foot (91 cm) diameter loop made 
of aluminum tubing and a plastic housing that contains the tuning 
capacitor, motor, and coupling loop.  No control cable is required since 
the control voltage is sent from the control box in the shack to the 
motor in the antenna via the coaxial cable.


Before I purchase one of these I wanted to get an idea of the efficiency 
of such a small loop.  MFJ is silent on the subject so I did my own 
calculations.  The calculations and results are on a 1-page document 
that I uploaded to Dropbox and can be downloaded here:


https://www.dropbox.com/s/l8mv67cjrck2ssn/MFJ-1786-1788.pdf?dl=0

My calculations are based on the assumption that the efficiency of the 
MFJ antennas is similar to the (no longer manufactured) AEA Isoloop (my 
reasoning for that is in the document) and that AEA's specification of 
72% efficiency at 14 MHz is correct.  From that number I can calculate 
the efficiency and gain on all the other bands.


If you don't want to download the document, here is a summary of the 
results:


FreqEff Gain with respect to a half-wave dipole
MHz dB  dBd
7.0 -7.3-7.7
10.1-3.5-3.9
14.0-1.4-1.8
18.068  -0.6-1.0
21.0-0.4-0.8
24.89   -0.2-0.6
28.0-0.15   -0.5

I'd be interested in any comments people may have on the accuracy of
my assumptions and calculations in the document.

Alan N1AL
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Re: [Elecraft] Any value in using a Microkeyer III with a K3S or K4?

[Alan Bloom]

On 1/5/2021 2:17 PM, Jim Brown wrote:
You've got to be in the middle of NOWHERE with a 50dB over S9 neighbor 
to need more than a 16-bit sound card.


And that assumes the 50 dB over S9 signal is within the receiver 
passband.  Otherwise the receiver AGC will increase the volume of the 
weak signal to the point where sound card dynamic range is totally not 
an issue.


However, as Jim mentions on his web site, it is important to set audio 
levels so as not to over-drive the sound card input.  And apparently 
with some software it is important to set the sound card to the correct 
sample rate.


Alan N1AL

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Re: [Elecraft] Bad Form

[Alan Bloom]

I'm also using Thunderbird, but when I chose "Reply List" it puts my own 
email address in the "To" field instead of the list address.


I have to select "Reply All", in which case it does the right thing - 
reply to the sender as well as the list.


I'm using Firefox 78.6.0 (32-bit) on a Windows 10 laptop.  As I recall, 
the Linux version of Thunderbird did the same thing when I was using a 
Linux computer to access the Internet.


Alan N1AL


On 12/28/2020 1:42 PM, Jim Brown wrote:
That depends on your email software. I've long used Thunderbird, which 
gives me the choice of list or sender.


73, Jim K9YC

On 12/28/2020 12:20 PM, Gwen Patton wrote:

The reason for this happening is simple. The list is configured so that
when you REPLY to someone's post, it only puts that person's email 
address

in the TO: line.


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Re: [Elecraft] P3 question

[Alan Bloom]

480 x 272

On 12/18/2020 6:56 PM, Douglas Zwiebel wrote:

Anyone know what the screen resolution is?

Thanks
de Doug KR2Q
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Re: [Elecraft] Arecibo antenna collapses

[Alan Bloom]

On 12/2/2020 9:06 AM, j...@kk9a.com wrote:
I concur, it is sad that Arecibo will not be rebuilt. The director of 
operations is WP3R.  I worked him in the Sweepstakes contest a couple 
of weeks ago.


Yes, I met Sr. Vazquez WP3R when I visited Arecibo during a bicycle tour 
5 years ago.  A really nice guy.  He gave me a guided tour of the facility:


http://n1al.net/bike/pr_tour/day11.htm

So sad that the Arecibo dish is no more!

Alan N1AL


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Re: [Elecraft] P3 Transmit Display Failure

[Alan Bloom]

My first thought is there might be an intermittent RS-232 connection 
between the K3 and the P3.  That would prevent the P3 receiving the TX 
and RX commands from the K3 so that the P3 gets hung up in TX or RX 
mode.  If you can lay your hands on a spare RS-232 cable, I would try it 
to see if that fixes the problem.


If the RS-232 connection is confirmed OK and the problem still occurs, then:

Have you tried cycling power without restoring the config file?  If it 
really does require the config file restoration to restore proper 
operation then it must be some setting that is accidentally getting 
changed.  That can sometimes be caused by some computer software sending 
commands to the P3 via RS-232.  Try running the K3/P3 with no RS-232 
connection to the computer and see if you still see the problem.


If the problem occurs with no connection between the K3/P3 and the 
computer and you can confirm that it does require a config restore to 
get back to normal operation, then it sounds like the EEPROM in the P3 
must be going bad.  I have never heard of that happening, but I guess 
it's possible.


Alan N1AL


On 11/18/2020 12:19 PM, hawley, charles j jr wrote:

I have a reoccurring issue with the P3 display of the transmit cw display. 
Occasionally, the P3 doesn't display the TX waveform ( I have never noticed if 
this happening on SSB...probably not since I have never had to fix it). The fix 
is loading a config file stored when the problem was not happening.
I have tried to store a config file when it was happening just to see and then 
restore using that file. What happens then is the P3 display locked up with a 
dit and could not be unlocked.
After this test, I had to turn off the K3s and unpower the P3, restore power 
and turn the K3s on, and restore with a copy of the config which was taken when 
the display was showing transmit cw.
I'm thinking stray RF somehow causing this but never happened on SSB...and I 
have no clue what is getting flipped in the rig or P3 to have this happen.
Since I can restore the config and fix it, I guess I'm mostly curious why it's 
happening, any ideas?

Chuck Hawley
  c-haw...@illinois.edu

  Amateur Radio, KE9UW
  aka Jack, BMW Motorcycles



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Re: [Elecraft] [K3] Wetting current and CW paddles

[Alan Bloom]

Another solution is to use hermetically-sealed contacts.  I built a 
light-weight, single-lever key paddle using microswitches for the 
contacts.  It worked very well and never had problems with scratchy 
contacts.


http://n1al.net/ham/paddle.htm

Alan N1AL


On 10/15/2020 11:42 AM, Bill Frantz wrote:
When I built a single level paddle, I decided to use silver for the 
contacts

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Re: [Elecraft] P3 info

[Alan Bloom]

I believe that means that there is no RS-232 connection between the K3S 
and P3.  Check the K3S manual for the correct hookup.


Alan N1AL


On 10/8/2020 11:37 AM, Thaire Bryant wrote:

I have just noticed that after replacing my K3 with a K3S my P3 no longer
shows the center frequency of VFO A (7.234, 14.234, etc,).

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[Elecraft] OT: How to automatically delete OT (or other) posts in Thunderbird

[Alan Bloom]

I'm the guilty party who started the original off-topic thread. Sorry 
about that!



If you're using the Thunderbird email client, the following is the 
easiest way to automatically remove unwanted messages:



1. Click on the message.

2. Click on the menu icon (three horizontal lines) in the upper right of 
the window.


3. Click on "Message" then "Create Filter from Message".

4. Change the "From" field to "Subject". (Or leave it at "From" if you 
want to flag the sender rather than the subject.)


5. Change the "Is" field to "Contains"

6. In the next field, enter "OT" or whatever text you want to flag in 
the subject line.


7. In the sub-window below that, choose the folder you want to send the 
message to.  (Perhaps "Trash"?)


8. Click "OK"


Alan N1AL



On 10/7/2020 8:42 AM, Bill Frantz wrote:
Given that this thread very plainly contains "OT", for Off Topic, in 
the subject line, anyone wanting only information about Elecraft 
equipment should have already filtered it out.


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Re: [Elecraft] K4 Pricing Posted

[Alan Bloom]

Plus the K4 has a large, full-color, touchscreen display, Ethernet LAN, 
several USB ports, flexible antenna switching, etc. And it's all 
integrated in one box.



Alan N1AL


On 10/4/2020 9:31 AM, Gary J Ferdinand wrote:

Well, let’s think about this one a bit.  I for one was not disappointed with 
the pricing; I think they did a super job.

I have a K4D on first-group order for $4700.  The new price adds $300.  I’m ok 
with that due to the extreme circumstances involved with getting parts, etc.  
But there’s another way to look at it.

To get a rig from Elecraft pre-K4 such as the K3S, compared with the K4D, you 
would have to add a K3S SUB RX, synthesizer board, at least one CW or narrow 
SSB filter (or both), the I/O board for all the antenna connections, a P3, a P3 
SVGA option, a P3 TX monitor option, a digital voice recorder.  And, I’ve 
probably forgotten a few, such as the K4’s ethernet connection and all that 
implies.

Throw in the extras offered by the K4D and man this is a great deal.  For 
example the P3 cannot compare with the display on the K4(D).

Throw in performance and it’s even better.

Enjoy the hobby whatever you choose to get.  Fun is the name of the game.

73,

Gary W2CS




On Oct 3, 2020, at 12:09 AM, Dave  wrote:

I was disappointed to see the pricing for the K4. I thought the base K4 would 
be in or around $3500 to $3700 and perhaps $500 or so to go to the K4D. As it 
turns out, another $900 for the K4D. These prices do not include the ATU ($400) 
or even a hand-held Mic. The total for the K4D that I was thinking of 
purchasing would have been almost $5470. (+shipping ??) it’s out of my price 
range. It will be interesting to see what the K4HD goes for. I’m glad that I 
had my $1500 deposit refunded several months ago. I have to wonder if one will 
really be able to tell the difference between any K4 and the FTDX101D which can 
be purchased for under $3000 and includes the ATU and a Mic

I hope you folks enjoy the K4 as I’m sure it will be a great radio. I will 
continue to use my K3s as the price for that fine radio is dropping like crazy 
and has allowed me to pick up a second one for a surprisingly low price.

73,
Dave N8AG

Sent from Mail for Windows 10

From: elecraft-requ...@mailman.qth.net
Sent: Thursday, October 1, 2020 7:20 AM
To: elecraft@mailman.qth.net
Subject: Elecraft Digest, Vol 198, Issue 1

S

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Re: [Elecraft] Fire report

[Alan Bloom]

And it's not just in California.  Here where I'm staying in southern 
Utah there have been a number of wildfires recently.  In the middle of 
the desert!  Almost no trees here but with the heat we've been having 
there are lots of brush fires.



Alan N1AL


On 9/29/2020 2:35 PM, Fred Jensen wrote:


All we get in N. NV is dense smoke when the wind is from the SW, which 
is pretty much most of the time.  We have kids and grandkids in N. CA, 
all OK right now.  It isn't just the fires and evacuations however, 
the magnitude of these fires is disrupting things all over the state 
bigly.  It's a ripple effect and it takes awhile to subside even after 
the flames are out [which they are not, yet].  It normally starts to 
rain around Halloween or Veterans' Day.

elivered to a...@elecraft.com

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[Elecraft] Cheap keyer paddle?

[Alan Bloom]

I am currently "sheltering in place" far from home and would like to set
up a station here.  I'm an 11-hour drive from home so I need to buy all
new accessories. 

I already have a good Vibroplex key paddle at home so I don't need
another high-quality one.  The good ones seem to start at around $175,
which is way more than I want to pay for temporary use.  I once made a
homebrew paddle made out of bent aluminum sheet metal and a pair of
micro switches for the dot and dash contacts. ("A Lightweight Homemade
Keyer Paddle", QST, July 2009).  I was satisfied with that paddle, so
you can see that I am not obsessive about "feel". 

So who makes a decent, inexpensive key paddle?  (By the way, I don't
need the iambic feature, so a single-lever model would be fine.) 

Alan N1AL
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Re: [Elecraft] CW rise time setting

[Alan Bloom]

In the "good old days" key shaping was done simply by adding a capacitor
to the key line or equivalent.  That results in an exponential rise
and/or fall time, which is not optimum, so the time constant had to be
set pretty slow to avoid key clicks.  Typically 5-10 ms.  10 ms results
in "mushy" keying, especially at high CW speeds. 

Raised-cosine key shaping is close to optimum and is easy to implement
with a DSP.  It allows faster rise/fall times without key clicks.  I
assume Elecraft is using something like that. 

Alan N1AL 

On 2020-06-08 12:51, E.H. Russell wrote:

> I'm used to CW rise times in th 4-7ms range. Is this 2.5ms arrived at by a
> different metric? Is the curve added by sigmoidal shaping somehow excluded
> from the measurement?
> 
> Ed / w2rf
> 
> -Original Message-
> From: elecraft-boun...@mailman.qth.net  On
> Behalf Of Richard Stutsman
> Sent: Monday, June 8, 2020 1:31 PM
> To: David Gilbert 
> Cc: Elecraft Reflector 
> Subject: Re: [Elecraft] CW rise time setting
> 
> Yes, I would regard a 2.5 msec rise time (using appropriate sigmoid
> 
> shaping) to probably be ideal, in which case I would have no desire to
> modify or shorten it. I'll bet it will sound even better than a Drake or a
> Ten-Tec!
> 
> I hereby withdraw my previous request/opinion.
> 
> Rick N6IET
> 
> On Mon, Jun 8, 2020 at 10:27 AM David Gilbert < 
> ab7e...@gmail.com> wrote:
> 
>> You don't need to generate clicks to have a crisp CW tone.  Elecraft
> 
>> uses a pretty much optimally shaped waveform (some version of a cosine
> 
>> function) and if I remember correctly the rise time is only about 2.5
> 
>> msec, although I could be wrong about that last part.  And while you
> 
>> may be careful not to use short rise/fall times when the band is
> 
>> active, in the past there have been folks on the contesting reflector
> 
>> who openly admitted they purposely generate clicks by shortening the
> 
>> rise/fall times to give themselves elbow room.  I will always
> 
>> appreciate that Elecraft doesn't give those miscreants the means to
> pollute the band.
> 
>> 73,
> 
>> Dave   AB7E
> 
>> On Mon, Jun 8, 2020 at 9:23 AM Richard Stutsman <
>  rast...@gmail.com> wrote:
> 
> I for one would like to have some control over the rise/fall times.

> 

>> You want the cleanest (narrowest) of CW signals when operating on a

>> crowded band or in a contest - unless you're a rare DX station. Most

>> of my operations are 22wpm rag chews on very uncrowded bands. We're

>> often the only discernible signals on an entire CW band. And

>> conditions are often noisy with deep QSB. Why not allow those of us

>> operating in those circumstances to shorten the rise times a bit,

>> which makes it easier to copy in noisy conditions, when any close-in

>> clicks or thumps aren't going to bother anybody? Copying a 'soft'

>> weak CW signal is like trying to read a 'crisp' signal that's an

>> entire S-unit weaker, IMO.

> 

>> My TS-590sg let's me do that, and I love it!

> 

>> Will the K4 sound as good as a Drake T4C? (Just askin'.)

> 

>> Rick N6IET

> 

> N4ZR wrote:

> 

> Will the K4 have options for setting CW rise and fall times...?

> Hi Pete,

> Probably not. We've always been very careful to ensure our rigs

> have an exceptional clean, click-free CW signal. (Third-party

> testing bears this

> out.) Minimizing the bandwidth requires a very specific rise/fall

> time

>> and

> a hand-crafted sigmoidal shaping function in DSP.

> Colonel Sanders closely guards his fried chick recipe, Mrs. Fields

> won't reveal what's in her chocolate-chip cookies, and only

> selected firmware monks--sworn to secrecy--are privy to Elecraft's

> keying envelope coefficients :) 73, Wayne N6KR

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>>  ab7e...@gmail.com

> 

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Re: [Elecraft] P3 Beep off

[Alan Bloom]

Of course, that's for the K3.  The P3 doesn't have beep tones. 

Alan N1AL

On 2020-04-26 20:02, M. George wrote:

> Go to the CONFIG SW TONE setting and change it to ON (the default).
> 
> Max NG7M
> 
> On Sun, Apr 26, 2020 at 7:32 PM Mike March  wrote:
> 
>> On my P3, the beep function has been disabled.  I cannot find a reference
>> to this in the manual.  Has anyone else had this happen?  Thanks.
>> 
>> --
>> Michael March K4QU
>> 242 Clay Hill Dr.
>> Winchester, VA  22602
>> mikek...@gmail.com
>> 540-662-4279 home
>> 540-539-8500 cell
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Re: [Elecraft] Frequency display on P3?

[Alan Bloom]

The P3 has a menu entry to calibrate its frequency  MENU:Ref Cal 

The calibration prodedure is on page 37 of the manual.  I like to use an
AM broadcast station (preferably near the top of the band) for
calibration because these frequencies are highly accurate and AM mode
puts the carrier right at the center of the P3 display. 

Alan N1AL 

On 2020-04-24 19:13, Frank O'Donnell wrote:

> Here's what I'm sure is a beginner question.
> 
> If I feed an accurate signal from a waveform generator into my K3S, on the P3 
> it appears right about 120 Hz higher than the actual frequency. This seems to 
> be independent of the mode the K3S is in. What causes that?
> 
> I noticed this when I had my K3S/P3 running while working the ARRL Frequency 
> Measurement Test with other gear, and was curious about it.
> 
> Thanks much,
> 
> Frank K6FOD
> 
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Re: [Elecraft] K3s/P3 noise comparisons

[Alan Bloom]

> Since noise power scales with the square root of the bandwidth

That may be the source of the error.  Noise power scales directly with
the bandwidth.  (Noise *voltage* scales as the square root of the
bandwidth.) 

Since the P3's effective bandwidth is 11 Hz and the K3 sensitivity is
specified for 500 Hz, the P3 should be showing 

10 * log (500/11) = 16.5 dB lower than the P3. 

If the P3 is reading -162 dBm, then that corresponds to -145.5 dBm on
the K3, close to the -145 dBm spec. 

Alan N1AL 

On 2020-04-18 12:33, Jim Miller wrote:

> I'm doing some work on measuring RFI levels on 6m at my QTH.
> 
> One tool I'm using is the P3 with averaging set to 20 to make for easier
> reading.
> 
> With the K3s preamp 2 engaged I read -162dbm on the P3 scale when connected
> to a 50ohm dummy load.
> 
> I'm trying to correlate that to the MDS numbers for the K3s.
> 
> The K3s specification with Pre2 engaged is -145dbm measured in a 500hz
> bandwidth.
> 
> The effective bandwidth of the P3 per the P3 manual is Scale/450 which for
> 5K that I'm using is 11hz.
> 
> Since noise power scales with the square root of the bandwidth that
> should result in a ratio of SQRT(45) or 6.7. 10*log(6.7) = 8.2
> 
> Adding -162 to 8.2 only brings me to -153db.
> 
> So it seems I'm missing something. The P3 is telling me the K3s is 8db more
> sensitive than its specification.
> 
> What am I missing?
> 
> Thanks
> 
> JIm ab3cv
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Re: [Elecraft] P3 TX Monitor Question

[Alan Bloom]

In the TX Monitor Menu, check that  "Mod En" is enabled.  

Alan N1AL 

On 2020-04-10 21:48, Tom and Karen Norris wrote:

> I've been almost 2 years getting to this point of assembling the P3 Kit.
> The K3s I got to right away. Now that I have the P3 together and working
> the only problem I have is I cannot get the CW Split signal to show on the
> P3 display. I've gone through the Fred Cady (what a life saver! We will
> miss him and his way of saying things that even I can understand!) K3s/P3
> manual and duplicated his TXMonMenu settings, the PEP and SWR meters work
> (Fred said they may not match the K3s meters and they don't) but the CW
> Transmit signal does not appear on the display at all, either with Split
> enabled or disabled. Is there another setting someplace that I'm missing or
> a setting that I have wrong? Any help would be greatly appreciated!
> Tom NB5Q
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Re: [Elecraft] Question for California Hams

[Alan Bloom]

It sounds like one guy's rant to me.  He refers to a letter supposedly
sent by CAL FIRE, but gives no reference to back up the claim. 

In Sonoma County, California we have a 146.13/73 repeater system at the
County site on Sonoma Mountain that has been there for years.  I'm a
member of the local ACS (Auxiliary Communications Service, basically
RACES) but I have heard nothing about any changes to the repeater
status. 

CAL FIRE's Volunteers In Prevention (VIP) program uses specially-trained
Amateur Radio operators to assist CAL FIRE's efforts during wildland
fires and other emergencies.  It's been many years since I was involved,
but the program is still going strong as far as I know: 

https://www.fire.ca.gov/programs/communications/volunteers-in-prevention/


Alan N1AL 

On 2019-10-12 10:58, l...@ka7ftp.com wrote:

> Wondering if this is true:
> 
> https://halturnerradioshow.com/index.php/en/news-page/news-nation/california-officials-declare-ham-radio-no-longer-a-benefit-demands-ham-radio-repeater-infrastructure-to-be-removed
> 
> A friend sent me this.
> 
> Len
> 
> 73
> 
> KA7FTP
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Re: [Elecraft] Has anyone tried UBUNTU (Linux

[Alan Bloom]

Yes I have been using Ubuntu for years. I used to have probllems with it
 Every once in awhile something would break after an update.  But since
I upgraded to version 16.04 LTS (Long Term Support version introduced in
2016) it has been stable. 

At first I just used it for email and surfing the Internet - all my
iimportant software was on a separate Windows computer.  As time goes by
there are more and ore applications available for Linux and now I even
run some sophisticated engineering software on that computer. 

The main problem I have had is that installing drivers can be a pain  I
bought a certain printer model specifically because they claimed they
had a driver for Linux  Turned out yes they had a driver but it didn't
work.  (I should have Googled it before I bought it to find that out.) 
I had to use the printer on a Windows machine instead. 

Alan N1AL 

On 2019-07-31 20:41, riese-k3...@juno.com wrote:

> when it was introduced i had a machine that would double boot
> worked well, stable but not much written for it
> 
> Bob K3DJC
> 
> On Wed, 31 Jul 2019 22:49:03 -0400 Steve Boles  writes: 
> 
>> Has anyone tried UBUNTU (Linux)...  73 - Steve (ARS: WB4SED)
> 
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Re: [Elecraft] P3 Not Zeroed

[Alan Bloom]

Re: choice of test signal for calibrating the P3 

> I am not certain why Alan prefers using a BCB signal, but WWV is an AM signal 

> with defined frequency and tone frequencies. 

Two reasons.  The main one is that the local AM station's signal doesn't
depend on propagation.  It is always there, day or night, with no
fading.  The other reason is that the relatively low frequency is less
affected by the K3 calibration.  For calibrating the P3 that gives a
slight advantage. 

But WWV works fine also. 

Alan
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Re: [Elecraft] P3 Not Zeroed

[Alan Bloom]

You could be right.  I'm out of town right now so I can't check it.  But
I think I remember that in some of the digital modes the definition of
VFO A frequency is different. 

Alan N1AL 

On 2019-07-23 11:36, Joe Subich, W4TV wrote:

> On 2019-07-23 12:47 PM, Alan Bloom wrote: 
> 
>> Also be aware that the center frequency differs depending on mode.
> 
> The P3 *should be able to account for that* by using the FI get:
> 
>> FI * (I.F. Center Frequency; GET only)
>> RSP format: Fi; where  represents the last 4 digits of the K3's 
>> present I.F. center frequency in Hz.  Example: If  = 5000, the I.F. 
>> center frequency is 8215000 Hz.  Intended for use with panadapters, which 
>> need to keep track of the exact I.F. center frequency as filter bandwidths 
>> and shifts are changed by the
>> operator.
> 
> 73,
> 
> ... Joe, W4TV
> 
> On 2019-07-23 12:47 PM, Alan Bloom wrote: 
> 
>> Good advice.
>> 
>> Also be aware that the center frequency differs depending on mode.  For
>> example, it is the supressed carrier frequency on SSB but is offset by
>> typically 600 Hz on CW.
>> 
>> I like to use AM mode for frequeny calibration.  After doing a frequency
>> calibration on the K3, tune to a signal on the AM broadcast band and
>> adjust the P3 frequency calibration.  (MENU:RefCal.  Cal procedurre is
>> on page 39 of the manual)  As I recall, AM broadcast stations are
>> required to be within 20 Hz of nominal frequency but are typically much
>> closer than that.
>> 
>> Alan N1AL
> 
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Re: [Elecraft] P3 Not Zeroed

[Alan Bloom]

Good advice. 

Also be aware that the center frequency differs depending on mode.  For
example, it is the supressed carrier frequency on SSB but is offset by
typically 600 Hz on CW. 

I like to use AM mode for frequeny calibration.  After doing a frequency
calibration on the K3, tune to a signal on the AM broadcast band and
adjust the P3 frequency calibration.  (MENU:RefCal.  Cal procedurre is
on page 39 of the manual)  As I recall, AM broadcast stations are
required to be within 20 Hz of nominal frequency but are typically much
closer than that.

Alan N1AL 

On 2019-07-23 08:20, Bob McGraw K4TAX wrote:

> First make sure the radio is correct on all WWV frequencies.   I use CW mode 
> and Auto Spot.  That will get to within 2 Hz or better. Adjust the Ref freq 
> to calibrate. 
> 
> Then you can calibrate the P3 to the radio. 
> 
> No tuning or listening for zero beat required. 
> 
> Bob, K4TAX
> 
> Sent from my iPhone
> 
> On Jul 23, 2019, at 9:54 AM, Kevin, N4TT  wrote:
> 
> Hi Jim:
> 
> I thought I had the right adjustment on the P3 but it seems global. I can't
> figure out why WWV can be spot on and then another signal off. I can't even
> be sure if it is the radio or the P3 (or me) at this point. I'll keep
> digging.
> 
> Kev
> 
> On Tue, Jul 23, 2019 at 3:57 AM Jim Brown  wrote:
> 
> It's been a while since I looked at the manuals for my K3 and P3, but I
> do recall that there are calibration procedures for both.
> 
> 73, Jim K9YC
> 
> On 7/22/2019 9:28 PM, Kevin, N4TT wrote:
> I noticed my P3 doesn't seem to be zeroed with the K3s. When I tune in a CW 
> signal with a 600 Hz pitch the P3 is off by 71 Hz. Not much but, I
> expected  - zero.
> 
> In AM - WWV at 5 MHz the P3 seems spot on. 
> 
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Re: [Elecraft] P3 center frequency

[Alan Bloom]

I'm out of town right now so I can't test this out.  But when it came up
before, as I recall the problem turned out to be as Tom says, some
software programs send frequency and band commands in an order that
causes the P3 to temporarily be tuned outside the span window. 

Normally, the P3 tries to keep the VFO A frequency within the span, so
when the "wrong" frequency appears, the P3 re-tunes itself.  When the
frequency returns to the correct value, the P3 retunes again to put that
frequency somewheree within the span, using rules determined by the MENU
FixMode selection. 

A think a workaround for this is to set FixMode to "Static".  As I say,
I am not able to test that right now since I'm out of town, but I think
that will force the frequency range to be corrrect even after a
software-initiated band change. 

Alan N1AL

On 2019-07-22 08:23, Tom wrote:

> Hi,
> Sorry, I forgot my signature.  It's Tom va2fsq.
> I've tried this out quite a bit with Win4K3Suite, and in fixed mode changing 
> bands always results in the correct behavior.  The left frequency in the P3 
> display is always where it was left the last time you were on that band.
> Win4K3Suite issues the BN command when it switches bands.  It's possible that 
> other packages where you see this behavior do not.
> For example, N1MM, DXLab, actually sends the last frequency that was on the 
> previous band.  It does not issue a BN command.  Other packages might do 
> similar things.  
> However, is this intermittent?  Or does it always occur.  Which application?  
> Is it possible that you QSY'd outside the span at some point?  The left 
> frequency will then be different.
> So unless this is intermittent, or caused by the application, it would seem 
> that the P3 is operating correctly.
> 73 Tom
> Va2fsq.com
> 
> -Original Message-
> From: elecraft-boun...@mailman.qth.net  On 
> Behalf Of Fred Jensen
> Sent: July 21, 2019 8:04 PM
> To: elecraft@mailman.qth.net
> Subject: Re: [Elecraft] P3 center frequency
> 
> Not sure who I'm talking to here, no signature, no call.  It's a little hard 
> to explain but ...
> 
> Assume you set SPAN=100 KHz and put the left edge at the bottom of each band. 
>  Changing bands back and forth using the BAND ^/v switch will preserve these 
> settings, and every time you come back to a previous band, they will appear 
> ... so long as you don't touch any of the P3 controls.  However, using CAT 
> commands [e.g. from a logger], you can change to a new band and the settings 
> will hold, however returning to the previous band, the SPAN will still be 100 
> KHz but the center frequency will have moved and the left edge will no longer 
> be at the bottom of the band.  Admittedly, it's a bit hard to duplicate but 
> the circumstances that cause it are common in contesting and it has been 
> duplicated by several folk, including me.
> 
> The issue has been raised here on the list more than once.  I think it first 
> came up several years ago, which could be 1 or 6, even Apollo 11 seems like 
> yesterday to me these days. [:-)  It has some of the earmarks of an 
> intentional attempt to "do something good" in the firmware which turned out 
> to be not so good, but I really don't know.  For whatever the reason, I 
> expect it to come back to the settings it had when I left that band.
> 
> As Randy said, it is really annoying.  I, and I think most, use the P3 
> visually instead of looking at the K3.  If I set the left edge at the bottom 
> of the band and the SPAN at 100 KHz, I automatically visualize the 1st 100 
> KHz directly from the screen. If it's changed as a result of band changes, my 
> mental picture of that band segment is wrong.
> 
> 73,
> Fred ["Skip"] K6DGW
> Sparks NV DM09dn
> Washoe County
> 
> On 7/21/2019 4:20 PM, Tom wrote: Hi,
> What exactly do you mean?
> It is always set to whatever you send.  If you explain this a little more 
> perhaps I can help.
> 73
> 
> -Original Message-
> From: elecraft-boun...@mailman.qth.net  On 
> Behalf Of Randy Farmer
> Sent: July 21, 2019 2:44 PM
> To: elecraft@mailman.qth.net
> Subject: Re: [Elecraft] P3 center frequency
> 
> It's been brought up several times in the last two or three years. No 
> response from the P3 software guys. It's EXTREMELY annoying that the P3 won't 
> respect the center frequency setting if the radio is tuned via any CAT 
> command. I've given up on hoping it will ever be fixed. My guess is that it's 
> all hands and the cooks working on K4 software these days.
> 
> 73...
> Randy, W8FN
> 
> On 7/21/2019 12:45 PM, Fred Jensen wrote: Jim: In general, yes, if you change 
> bands with BAND ^/v.  When you
> change bands via the CAT, the P3 center freq won't always end up where
> you last had it.  I believe SPAN width is preserved but the span
> limits show up strange.  It's a known issue, has been discussed at
> some length here a few months ago.
> 
> 73,
> Fred ["Skip"] K6DGW
> Sparks NV DM09dn
> Washoe County
> 
> On 7/21/2019 10:31 AM, 

Re: [Elecraft] K4 DSP bit width

[Alan Bloom]

> Getting a 16 bit converter that fast, approaches the limit of available 
> technology. 

Right.  At least at reasonable cost. 

> These converters are pipeline architecture and have better than 90 db dynamic 
> range. 

Theoretically the dynamic range (ADC overload to noise floor) of an ADC
is a little better than 6 dB * number of bits, which would  be over 96
dB for a 16-bit ADC.  But they are never that good in practice.  I
believe 90 dB is way optimistic, especially when you take into account
the analog circuitry that is needed in front of the ADC. 

For example, the 16-bit LTC2107 from Analog Devices has 80 dBFS
signal-to-noise ratio.  Note that is a theoretical figure in that it
assumes no degradation at all by external circuitry.  This
state-of-the-art device draws 1.28W of power and costs $99 in 1000-piece
quantity. 

> Looking at S units, there is 88 db from S1 to 40 over S9 before any 
> attenuation or 

> AGC is applied prior to  the ADC. 

>> K3S   K4HD   Feature
>> 24 16  ADC width 

As others have noted, that's an "apples and oranges" comparison because
the 16-bit direct-sampling ADC is way oversampled compared to the 24-bit
ADC at baseband or low-frequency IF.  The S/N ratio of an ADC is
improved by 

10 * log(sample_rate/receive_bandwidth) dB 

For example, if the sample rate is 130 MHz and the receive bandwidth is
500 Hz, that's about a 54 dB improvement.  If the ADC dyanamic range,
including all external circuitry, is (let's say) 75 dB then the 500 Hz
dynamic range is 129 dB.  I think with current technology at reasonable
cost, the high 120's dB is about the best you can do with a
direct-sampling receiver and many don't do that well. 

By constrast, I believe the blocking dynamic range of a K3S is about 150
dB in a 500 Hz bandiwdth.  I assume the K4 high-dynamic-range option
will be similar.  Whether you need the extra 20-30 dB of blocking
dynamic range depends on your situation and what you plan to use the
radio for. 

Alan N1AL 

On 2019-05-29 09:37, W2xj wrote:

> The K4 is a direct sampling radio. It has no IF. It samples directly to IQ 
> baseband and performs all filtering and processing in the digital domain. 
> That requires a very high speed ADC. In this case it is just above the 
> Nyquist limit for 6 meters. Getting a 16 bit converter that fast approaches 
> the limit of available technology. These converters are pipeline architecture 
> and have better than 90 db dynamic range.  Looking at S units, there is 88 db 
> from S1 to 40 over S9 before any attenuation or AGC is applied prior to  the 
> ADC. The problem comes when there are signals exceeding that dynamic range 
> like working someone who might be S1 or S2 while someone else is transmitting 
> nearby as a direct conversion radio has no front end selectivity. As Eric 
> already explained, this is the reason for the K4HD option. This appears to 
> essentially be a K3S superhet single conversion front end that feeds an 
> approximate 8 MHz IF into the ADC. It would then provide a very narrow band 
> receptio!
 n o
> ption for the K4.
> 
> Looking at K3s architecture, the ADC is a PCM1804 which is a delta sigma 
> converter which is basically a one bit ADC clocked at 768 times the sample 
> rate or somewhere between approximately 24 and 36 MHz depending on what 
> sample rate Elecraft selected. In the mode used in the K3S it can sample up 
> to 48 KHz although there are other modes permitting up to 192 KHz. The one 
> bit sample is decimated to 24 bits. This ADC is a fairly typical high end 
> stereo audio converter.
> 
> The two approaches are very different and each fulfills a different need. 
> Fortuneately, the K4 can provide both with the right options installed.
> 
> Sent from my iPad
> 
>> On May 29, 2019, at 1:08 AM, Bill Frantz  wrote:
>> 
>> A friend and I were discussing the K4HD and he said that it sounds a lot 
>> like the K3S. Well, we both agreed that since the K3S has world class 
>> receiver specs, that would not be a bad thing.
>> 
>> I started comparing the information about the K4HD with the K3S manual and 
>> found:
>> 
>> K3S   K4HD   Feature
>> 8.215MHz  ~8MHz  First IF
>> 15KHz  ? Second IF (if used in the K4)
>> 24 16ADC width
>> ~30KHz?   122MHz ADC sample rate (WAG for the K3S)
>> 5 2+1Crystal filters (one empty slot is from a post on this 
>> list.)
>> 
>> Note: In the K4 FAQ there are forward references to a K4HD section, but I 
>> couldn't find it on the web site.
>> 
>> Analysis and wild speculation
>> 
>> Both DSPs and ADC technology have had at least 10 years to improve between 
>> the K3S and the K4. WHile I don't track ADC tech, DSPs are computers and we 
>> all know what has happened in computers. The basic processors are somewhat 
>> faster, and there are many more cores on a chip. The K4 certain to have 
>> taken advantage of these improvements.
>> 
>> The K3S uses a 32 bit floating point DSP, and I don't see any reason to 
>> change 

Re: [Elecraft] BIZARRE OFFERING FROM MFJ

[Alan Bloom]

I've long had mixed feelings about MFJ.  They have some very
interesting, innovative, and cost-competitive products.  However
sometimes the quality isn't there.  For example I have an MFJ antenna
analyzer that was intermittent until I fixed a poor ground connection. 
I forget the details, but as I recall the problem was partly one of
design. 

Alan N1AL 

On 2019-04-07 09:28, Wayne Burdick wrote:

> I've used many MFJ products and in have had very little trouble with any of 
> them. For example, I make frequent use an MFJ-223 hand-held VNA -- it's 
> versatile and does the job. I've also used their manual tuners, antenna 
> switches, and portable/mobile whips. They have a very comprehensive product 
> line that's really unique in the industry.
> 
> That said, I do have some suggestions for MFJ's engineering team on how they 
> might improve their ATU. 
> 
> Looking at the photo, I see that they used much smaller toroidal cores for 5 
> of the 8 inductors in the L network. This could result in excessive heating, 
> especially on the higher bands, at full power into a worst-case match. We 
> specified T68 sized cores to remain conservative based on extensive testing. 
> Also, if you click on the photo to see the details, you'll see what appears 
> to be very inconsistent hand soldering of the SMD components. While this 
> doesn't necessarily worsen performance or reliability, it should be done in a 
> way that inspires confidence in the buyer. (Easy for me to say, of course. We 
> have the luxury of mass-producing these assemblies using automated 
> pick-and-place equipment at our fabricator in Monterey.)
> 
> Wayne
> N6KR
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Re: [Elecraft] Minicircuits splitter for diversity?

[Alan Bloom]

And don't forget that the isolation spec assumes a perfectd 50-ohm
termination on all ports.  For example if one of the ports is seeing a
load with a 10 dB return loss, then the isolation will be no better than
10 dB. 

Alan N1AL 

On 2017-11-06 13:06, Jim Brown wrote:

> No -- the Mini-Circuits splitters provide significant isolation between the 
> ports so that, for example, a local oscillator on one port isn't fed to the 
> other port(s). The degree of this is the dB spec for isolation.
> 
> 73, Jim K9YC
> 
> On 11/6/2017 12:21 PM, Michael Walker wrote: 
> 
>> Is that any different than your basic cable splitter other than it has BNC
>> and not F connectors?
> 
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Re: [Elecraft] Should we expect something new in Dayton?

[Alan Bloom]

The Dayton Hamvention is no longer in Dayton.  I guess the Hara Arena 
just got too scuzzy.  The event is now in Xenia, a few miles east of Dayton.


http://hamvention.org/wp-content/uploads/2017/03/Map-to-Xenia.pdf

Alan N1AL


On 05/02/2017 04:33 PM, Fred Jensen wrote:
...

Wish I could come.  I've only been to HARA once, years ago, it was a
dump then, and it wasn't even Hamvention sadly.

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Re: [Elecraft] OT: Package shippers

[Alan Bloom]

I've had exactly the opposite experience than Ken - excellent, flawless 
performance from FedEx and horrible experience with the post office.


The local post office claims to have found a rule that says that if your 
house is more than 1/2 mile from the public highway, they don't have to 
deliver packages.  So to save the driver the 5 minutes it would take to 
drive to my door, I have to make a more than 1-hour round trip to the 
post office and stand in line to pick up my package.


When I order on-line I always try to get it shipped FexEx, even if it 
costs more.  Unfortunately Amazon doesn't give you the option to specify 
the shipping company, so I have to have everything shipped to a friend's 
house in case it comes by USPS.


Alan N1AL



On 04/26/2017 11:13 AM, Rick Tavan wrote:

The radio world seems to be converging on your opinion, Ken. Almost all
packages I've received in the past few years have come via UPS and I use it
myself for my occasional outbound shipments. That being said, there is a
disturbing relationship between UPS and USPS: In some rural areas, and
maybe elsewhere, UPS can hand off a package for ultimate delivery by USPS.
Seems reasonable except that the two providers have different conditions of
carriage. UPS agrees to deliver to a home doorstep while USPS requires that
a home have an official USPS mailbox which they use when able. If USPS
delivers a package too large for the mailbox, then they will deliver to the
doorstep. However, if there is no mailbox, USPS will not deliver any
package of any size. They return the package to the sender, no notice to or
recourse for the intended recipient. UPS and mail-order shippers don't
disclose this occasional glitch (at least I've not seen it) so both
shippers and recipients get screwed. Moral of the story: If you don't have
a mailbox, don't order packages that will be shipped by UPS. Better, use
someone else's delivery address that has a mailbox. If you have a PO box,
some US Post Offices will accept courier packages addressed to their own
street address with an appended box number. But the shipper must specify
that street address because UPS will not deliver to a PO Box explicitly!
Catch 22.

73,

/Rick N6XI

On Wed, Apr 26, 2017 at 10:56 AM, Ken G Kopp  wrote:


I suspect for each of us our view of shippers will vary widel.

While certainly not a "large" shipper, Rose (Elecraft Covers)
ships a number of packages a week, with many going to
foreign destinations.

She -always- ships via the USPS and mostly via Priority Mail.
In almost ten years she's had one package go astray, and
that was due to me typing a wrong ZIP code.  A Priority Mail
package will reach any US destination in no more then three
days.

FedEx is absolutely terrible!  One fat envelope of legal papers
from our bank was left on the driveway, laying in two inches
of water.  Another was tossed over a fence into the yard.  Yet
another was dropped near the BACK door of the house.  Didn't
find it until a trace was instituted for the "missing" delivery.

When we order fabric, webbing, Velcro supplies, the vendor
is told in no uncertain terms if the order is sent vis FedEx it
will be the last one they get.  A gawd awful company! (:-)

FedEx problems may stem from their use of non-company
contract drivers in their trucks ... at least in this area.

UPS is OK in our view ... all of Rose's orders are shipped via
UPS or the USPS.

Trivia:  A case shipped to Istanbul via USPS Airmail was
delivered in Turkey in -five- days!!

FWIW ...

73!

Ken - K0PP
elecraftcov...@gmail.com
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Re: [Elecraft] Another really good reason to come to the Visailia DX convention this weekend...

[Alan Bloom]

The IEC 555 standard (later superseded by IEC 61000-3-2) specifies 
allowed harmonic distortion in the power supply current of electronic 
equipment:


https://en.wikipedia.org/wiki/IEC_61000-3-2

I believe it is mandatory in Europe and some other countries but not the 
United States:


http://www.metlabs.com/emc/emc-testing-requirement-for-it-equipment-varies-by-country/

Alan N1AL


On 04/26/2017 04:04 AM, David Woolley wrote:

I don't believe that it is legal to market a power supply that only
draws current on input peaks in either the USA or EU these days.  Power
supplies are supposed to spread the current demand over a significant
part of the cycle.  I believe this is done by having a relatively low
value capacitor on the mains side and relying on the switching regulator
to compensate for the wide voltage variations across each cycle.  I
believe that even applies to wall warts.

This "power factor correction" will not be perfect, so the peak current
will still be more than for a resistive load.


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Re: [Elecraft] [Elecraft_K3] New from Elecraft: KPA1500 amplifier with built-in ATU, separate power supply

[Alan Bloom]

With 1500W of power, if the SWR is greater than 3:1 you may be exceeding 
the ratings of the feedline.  For example, Belden 9914 is rated at a 
maximum of 300 VRMS, which is 1800W with a 50-ohm feedline or only 600W 
with a 3:1 SWR.  At 30 MHz, RG-8/213 style coax is typically rated at 
1500W with a 1:1 SWR.


It's true that you can do more than that with low-duty-factor modes like 
CW and SSB, but if you are running much more than 3:1 SWR you may be in 
danger of damaging the feedline.


Alan N1AL


On 04/21/2017 06:28 AM, Jim Miller wrote:

Wes

Can you describe your affected antennas?

73

Jim ab3cv

On Apr 21, 2017, at 8:56 AM, Wes Stewart 
wrote:

A couple of points.

If you believe that an SWR of >3 necessarily degrades the efficiency
of an antenna, you are simply wrong.

If the "tuner" components have to be derated to this extent then
perhaps it should be called a line flattener rather than a tuner
because a lot of guys are still going to need a tuner.




On 4/21/2017 4:34 AM, j...@kk9a.com wrote: The KPA1500 tuner range
is fine. If your antennas have >3:1 SWR you need to do some work
outside. It will help your signal much more than the amp. Even when
I operated the RTTY Roundup in January after an ice storm my
antennas were within this amplifiers SWR range.

John KK9A


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Re: [Elecraft] Help me choose my first HF rig

[Alan Bloom]

On 04/14/2017 03:20 AM, aj4tf wrote:

You will not regret an Elecraft purchase even if it is your first radio.


This thread is getting pretty long but I can't help but chime in.

If money is an issue (i.e. you're not part of the 1%), then I think 
buying a used rig is a great way to go.  If you don't like it or decide 
to upgrade then you can sell it for close to what you paid for it. 
Think of it as renting a radio while you get some operating experience. 
After you've been on the air for a year or so, you will have a much 
better idea of what you want and can make a more-informed purchase.


Something like a used K2/100 would make a great starter rig.

Alan N1AL
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Re: [Elecraft] K2 panadapter bandwidth?

[Alan Bloom]

I don't believe this is a limitation of the K2.  The panadapter 
bandwidth is limited by the bandwidth of the sound card.


By the way, if the sound card's sample rate is 192 kHz, the panadapter 
bandwidth is actually somewhat less than that, limited by the 
anti-aliasing filter in the sound card, typically 170-180 kHz.  In 
contrast, the P3 bandwidth is flat out to 200 kHz.


Alan N1AL


On 04/07/2017 09:28 PM, Harry Yingst via Elecraft wrote:

I was curious as to those running a panadapter with the K2.
How much bandwidth are you able to see?
I hooked up my FiFi SDR to the IF out and at 192 khz the band edges are faded 
out.
Thank you


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Re: [Elecraft] XG3 and short whip as an air standard

[Alan Bloom]

One thing to keep in mind is that the XG3 has a square wave output so
there are lots of harmonics.  One consequence is you can't use it with a
directional coupler to measure SWR unless you filter out the harmonics
somehow.  Also you may need to worry about interference to other
services, although the power level is low enough that may not be an issue.

Alan N1AL


On 04/07/2017 04:03 AM, David Cutter wrote:

The XG3 has a calibrated output into a 50ohm load and can be varied
over a wide range of power and frequency.  How can I use this as a
standard source for field strength measurements?

For instance, could I build passive networks to match a whip to the
XG3 on each band of interest and calculate the radiation from the
whip knowing its input from the network?  Since the XG3 output is
variable, the loss in the networks can be adjusted to suit.

Could I use, say a *standard* 1m copper wire whip (ie <<1wavelength
on HF) to easily obtain uV/m? It could all be mounted in a biscuit
tin as I once saw in a magazine many years ago.  Connecting a similar
whip to the K3 with its calibrated dBm facility, I'm hoping this
could all connect together in a modest home facility for
experimentation and learning.

David G3UNA


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Re: [Elecraft] account suspension

[Alan Bloom]

I try not to post about off-topic items, but I can't resist.

There's probably nothing you can do to absolutely protect any computer 
that is connected to the Internet.  Someday you *WILL* click on some 
attachment or there will be an operating system bug that doesn't get 
caught and corrected in time to save you.


So what I do is have two computers.  The Windows 7 machine with all my 
important stuff has no connection to the Internet or to any other 
computer or device that is connected to the Internet.  Sitting next to 
it is a Linux computer connected to the Internet.  If the Win7 computer 
needs to download some file from a web site it is transferred with a 
thumb drive from the Linux machine.


Of course, even that is not 100.0% foolproof because there could be a 
virus in a file on the thumb drive, but it is way, way safer.


Alan N1AL


On 03/07/2017 01:31 PM, Matt Zilmer wrote:
> Sometimes, being paranoid (or OCD) isn't enough.  After a friend's
> system was ransomed, I chose the most paranoid path I could afford:
>
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Re: [Elecraft] [K3] AGC White Paper

[Alan Bloom]

If the AGC is working right, it is equivalent to manually riding the RF 
gain control.  It shouldn't affect the decoding.


If the AGC time constant is too fast then, yes, it can cause distortion 
and degrade the decoding.  But that should never happen in a 
properly-designed AGC system.


AGC makes the decoder's job easier, not harder, because it reduces the 
dynamic range the decoder has to deal with.


Alan N1AL


On 03/07/2017 01:19 PM, Ed Muns wrote:

Decoders operate on the audio stream presented to them from the receiver.
The decoding algorithms use the difference in audio level at each instant in
time to make bit decisions.  AGC reduces those differences and thus
increases the bit error rate.

Of course, it is important to adjust the absolute audio levels so that the
dynamic range of the signal(s) is placed within the dynamic range of the
decoder.  But, compressing the dynamic range, i.e., AGC, increases the error
rate of the decoder.

Ed W0YK
_

-Original Message-
From: Bill Frantz [mailto:fra...@pwpconsult.com]
Sent: 07 March, 2017 13:05
To: e...@w0yk.com
Cc: elecraft@mailman.qth.net
Subject: RE: [Elecraft] [K3] AGC White Paper

What I get using a relatively flat AGC is automation of my
riding the RF gain control. I don't see how this kind of
automation affects decoder performance. It should help
performance as the decoder has a nearly constant level signal to
work with. Please explain.

Thanks - Bill AE6JV

On 3/7/17 at 11:37 AM, e...@w0yk.com (Ed Muns) wrote:


Just the opposite.  Most digital signal decoders work best with the least
AGC action possible, even AGC Off.  AGC constrains decoder performance.

Ed W0YK
_

-Original Message-
From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Bill
Frantz
...
Now to use SLP=15 for digital, where I want the AtoD to not
have to deal with a big range, while using something with more
dynamic range for voice/CW.


---
Bill Frantz|Security, like correctness, is| Periwinkle
(408)356-8506  |not an add-on feature. - Attr-| 16345
Englewood Ave
www.pwpconsult.com |ibuted to Andrew Tanenbaum| Los Gatos,
CA 95032



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Re: [Elecraft] A question on the P3 or actually the Tx Mon (K3)

[Alan Bloom]

Hi Paul,

It's just a matter of adjusting the SensorCal menu setting until the 
power reads the same as the device used for the calibration.  Of course, 
that assumes the calibration device is more accurate than the P3.  :=)


The nominal calibration value is 500.  The intent was to make it 
correspond to the same value as in a W2, but the match is not perfect. 
For one thing, the P3 uses a more-sophisticated algorithm to match the 
diode detector nonlinearity than the W2.


Alan N1AL


On 03/06/2017 08:56 AM, paul ecker via Elecraft wrote:

Alan - is there any documentation available on the procedure for calibrating 
the Tx Monitor?
73Paul
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Re: [Elecraft] A question on the P3 or actually the Tx Mon (K3)

[Alan Bloom]

Yes, it can be calibrated in a manner similar to the W2.  The menu entry 
is TXMonMenu/SensorCal.  There is a separate calibration stored for each 
sensor type (200W/2000W, HF/VHF).


Alan N1AL


On 03/06/2017 08:26 AM, paul ecker via Elecraft wrote:

A related question on this subject concerning the Tx Monitor. In
terms of Power & SWR readings, can the Transmit Monitor be calibrated
? Or have other users found no need to adjust readings right out of
the box? Reviewing the P3 manual on pages 34-35 there isn't much said
about this subject. 73Paulkc2nyu
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Re: [Elecraft] A question on the P3 or actually the Tx Mon

[Alan Bloom]

The P3 shows total forward power.  The power delivered to the feedline 
is forward minus reflected.


With a 13:1 SWR, 73.5% of the power is reflected and 26.5% is 
transmitted.  If the transmitted power is 92 watts then the total 
forward power should be 347 watts.


Alan N1AL


On 03/05/2017 06:58 PM, Grady Harper via Elecraft wrote:

I placed the DCHF-200 after my antenna tuner.  In other words, the
DCHF-200 is between my tuner and antenna.  When relying on my tuner
to match the antenna to the radio My power meter (on the P3) is
showing an SWR of a little over 13:1 (which is about right) .  My
meter on my tuner is showing about 92 watts of power headed down the
antenna,but the meter on the P3 is showing over 200 watts.  My
intended output being 100 watts.  Does the DCHF-200 show out-going
pwr + reflected pwr?  The tuner matches the antenna to the radio, and
the tuner meter shows a very very small amt. of reflected power. I
put the DCHF-200 at this location, because if I had the tuner
installed in the radio, this is where it would go.

The antenna is a fan dipole trimmed for 40 meters and 20 meters.  I
am on  3.810 MHz and without the tuner the SWR is about 13.2:1 here.
The tuner matches the antenna to the radio with a SWR of very close
to 1.0:1. .

AJ4YA Grady

Thanks.

Sent from my iPad
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Re: [Elecraft] Using your tower as a vertical - 160 or 80

[Alan Bloom]

Hi Erik,

It is certainly possible to use a separate filter in the feedline to 
each antenna.  For example, here's an article I wrote many years ago on 
how to homebrew your own:


http://p1k.arrl.org/pubs_archive/89595

Those filters are only good for 100W or so, but there is no fundamental 
reason they couldn't be scaled up to 1500W.  I haven't researched it, 
but I'm thinking there must be commercial equivalents as well.


Alan N1AL


On 02/28/2017 10:41 PM, Erik Basilier wrote:

Alan,

Thanks for your reply. Your approach would provide 40m capability to replace
the 40m capability that my (Sommer) beam loses through detuning.
However, I wonder how hard your tuner must work on 40? Enough to create
substantial feedline losses when the tuner is in the shack?
Anyway, I have another reason not to choose your approach:
I am rebuilding my station to support SO2R, and it is tough to avoid
interference between the two radios operating on different bands, especially
40 - 20 and with the antennas close together.
I found to my surprise, before the QST review came out, that the Low Band
Systems multiplexer and band pass filters (my setup includes 40m) eliminates
the interference problem. However, this scheme requires that the antennas be
on a shared feedline. With your approach the 40m antenna would no longer be
on the same feedline as the higher bands.



-Original Message-
From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Alan
Bloom
Sent: Tuesday, February 28, 2017 11:09 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] Using your tower as a vertical - 160 or 80

I use two of the top guy wires as an inverted vee.  There are insulators
near the top of the guys and about 50 feet or so down.  The vee is brought
to resonance on 80 meters with a center-tapped loading coil, which also acts
as a balun.  The best match was with the coax tapped right about at the end
of one side of the coil (and of course the coax shield to the grounded
center tap).

Works great on 80 meters without a tuner and on 40 meters with a tuner.

Alan N1AL


On 02/28/2017 09:42 PM, Erik Basilier wrote:

Years ago, after putting up a heavy-duty crank-up tower with several
antennas on a tall mast at the top, I was interested in loading up the
whole metal tree for 160 and/or 80. However, I didn't like the
prospect of transmitted power getting back into the shack via the
existing feedlines, causing all kinds of problems including losses.
From a surplus vendor I obtained four square slabs of ferrite (no
spec's) and taped them together to form a box-shaped common mode choke
around the existing feedlines (and rotor control cable etc). I didn't
have radials at the tower base, but a couple of long and wide copper
strips buried and connected to ground rods to which the tower was
grounded. I opened up the tower ground connection and I had a feed
point. Finding resonance was not as easy as using my antenna analyzer.
The signal from the analyzer was overwhelmed by picked-up broadcast

signals, rendering the analyzer unuseable. I got by using a custom
measurement setup.

It turned out that the entire metal tree resonated in the broadcast
band and was inductive at 160. I tuned it with a serial variable
capacitor, and found the antenna worked very well on 160. However, I
didn't continue using it, as I didn't feel safe not to have the tower
grounded. I pondered schemes to add some kind of gamma-like matching
device, but never got around to it. Also I never tried it on 80, but I
suspect it would not been ideal for low angle radiation.



Later I added more antennas to the mast, and with the added cables,
the whole bundle would no longer fit in the makeshift ferrite choke.
Out of curiosity I once again tried ungrounding the tower to check on
its characteristics as a vertical antenna. I could no longer find the
resonance I had seen and used before. Apparently, the ferrite choke
had been a crucial part of the scheme.



At this point I still don't have an antenna for 160 or 80. (I did try
an inverted vee off the tower for 80, but it caused terrible de-tuning
of the 40m part of my beam on the tower, so I gave up on that. Maybe I
should try a
sloper.)  I am thinking of putting up a dedicated vertical, but on my
small lot it would couple to the tower. Perhaps it would be better to
give the tower another look as my low-band vertical? My source of
ferrite slabs dried up years ago. I wonder if anyone else on the list
has used a similar approach and found a good way to choke off RF on a

bundle of feedlines?

Individual chokes don't seem very attractive to me as I have many
cables, but if one has to go that route then it would make sense to
look very carefully at the choice of chokes. I would also be
interested in knowing about others' experiences with feed systems that

leave the tower grounded.




Thanks in advance for any useful ideas!



73,

Erik K7TV

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Re: [Elecraft] Using your tower as a vertical - 160 or 80

[Alan Bloom]

I use two of the top guy wires as an inverted vee.  There are insulators 
near the top of the guys and about 50 feet or so down.  The vee is 
brought to resonance on 80 meters with a center-tapped loading coil, 
which also acts as a balun.  The best match was with the coax tapped 
right about at the end of one side of the coil (and of course the coax 
shield to the grounded center tap).


Works great on 80 meters without a tuner and on 40 meters with a tuner.

Alan N1AL


On 02/28/2017 09:42 PM, Erik Basilier wrote:

Years ago, after putting up a heavy-duty crank-up tower with several
antennas on a tall mast at the top, I was interested in loading up the whole
metal tree for 160 and/or 80. However, I didn't like the prospect of
transmitted power getting back into the shack via the existing feedlines,
causing all kinds of problems including losses. From a surplus vendor I
obtained four square slabs of ferrite (no spec's) and taped them together to
form a box-shaped common mode choke around the existing feedlines (and rotor
control cable etc). I didn't have radials at the tower base, but a couple of
long and wide copper strips buried and connected to ground rods to which the
tower was grounded. I opened up the tower ground connection and I had a feed
point. Finding resonance was not as easy as using my antenna analyzer. The
signal from the analyzer was overwhelmed by picked-up broadcast signals,
rendering the analyzer unuseable. I got by using a custom measurement setup.
It turned out that the entire metal tree resonated in the broadcast band and
was inductive at 160. I tuned it with a serial variable capacitor, and found
the antenna worked very well on 160. However, I didn't continue using it, as
I didn't feel safe not to have the tower grounded. I pondered schemes to add
some kind of gamma-like matching device, but never got around to it. Also I
never tried it on 80, but I suspect it would not been ideal for low angle
radiation.



Later I added more antennas to the mast, and with the added cables, the
whole bundle would no longer fit in the makeshift ferrite choke. Out of
curiosity I once again tried ungrounding the tower to check on its
characteristics as a vertical antenna. I could no longer find the resonance
I had seen and used before. Apparently, the ferrite choke had been a crucial
part of the scheme.



At this point I still don't have an antenna for 160 or 80. (I did try an
inverted vee off the tower for 80, but it caused terrible de-tuning of the
40m part of my beam on the tower, so I gave up on that. Maybe I should try a
sloper.)  I am thinking of putting up a dedicated vertical, but on my small
lot it would couple to the tower. Perhaps it would be better to give the
tower another look as my low-band vertical? My source of ferrite slabs dried
up years ago. I wonder if anyone else on the list has used a similar
approach and found a good way to choke off RF on a bundle of feedlines?
Individual chokes don't seem very attractive to me as I have many cables,
but if one has to go that route then it would make sense to look very
carefully at the choice of chokes. I would also be interested in knowing
about others' experiences with feed systems that leave the tower grounded.



Thanks in advance for any useful ideas!



73,

Erik K7TV

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Re: [Elecraft] The market for Full Kit Radios?

[Alan Bloom]

The P3 will work with the K2, although you need to modify the K2 to get 
an IF output signal.  In the P3 menu, go to "Xcvr Sel" and select "4915 
kHz" or "4915 kHz (inverted)" depending on which band you're on.


The P3 display does not indicate the K2 frequency, receive bandwidth, 
etc. so it's not a full integration, but it does work.


Alan N1AL


On 02/12/2017 03:28 PM, Ray Sills wrote:

Not to rain on anyone’s parade, but I’d wager you would need at least
several hundred, maybe thousands more serious buyers, for it to be
financially viable for Elecraft (or a 3rd party) to make a panadapter
for the K2.

BTW, is it not the case that the K2 is a traditional superhet?  That
means you’d not have a “free ride” that you would have with an SDR…
I/Q signals already available.  Maybe the P3 would be adaptable for
the K2..

73 de Ray K2ULR KX3 #211



On Feb 12, 2017, at 6:05 PM, Harlan Sherriff via Elecraft
 wrote:

I second the panadaptor idea

Sent from my iPhone


On Feb 12, 2017, at 4:46 PM, Brian Denley 
wrote:

I'd love a matching panadaptor kit for my K2 !

Brian Denley KB1VBF Sent from my iPad



73, Kev K4VD



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Re: [Elecraft] P3 TX Monitor with Two Sensors?

[Alan Bloom]

Yes, you could use an 8-pole double-throw relay to switch between the 
two sensors.


The P3 and W2 use the same information from the sensors and the same 
control lines.


Alan N1AL


On 01/13/2017 04:59 AM, Jean-François Ménard wrote:

Hi, thanks for the information. I just sent an email to Elecraft
support to let me know if I should check something prior the
utilization of the couplers I already have.

I really like to manual switch idea…. But I still wondering fi I
could use the AUX behind the K-Pod to manually switch between the 2
couplers already have, by creating a small circuit using a relay. It
could be a good way to maximise the use of the K-Pod too?!?!

Also, the information given by the P3 compared with the W2….. major
difference ??? more accurate ??? What are the major goals to use
antenna couplers with P3 instead of a W2 ???

Thanks for the information.

73 de Jeff | VA2SS

__ Jeff | VA2SS Jean-François
Ménard


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Re: [Elecraft] P3 TX Monitor with Two Sensors?

[Alan Bloom]

On 01/12/2017 04:44 PM, Harry Yingst via Elecraft wrote:

I was curious if anyone has been using the P3 TX Monitor with 2 sensors

If so how are you switching between the two sensors


I use this 4-port manual LAN switch, which can support up to 4 sensors:

https://www.amazon.com/gp/product/B00AUB3SSA/ref=oh_aui_detailpage_o04_s00?ie=UTF8=1

It was $10 when I bought it but the price has gone up.  If you search 
Amazon for "8P8C Manual switch" you'll see some other possibilities. 
For example, here's a two-port device for $6.55 with free shipping:


https://www.amazon.com/Network-Telephone-Manual-Sharing-Switch/dp/B0051MOUSK/ref=sr_1_1?s=pc=UTF8=1484288975=1-1=8P8C+Manual+switch

Alan
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