Re: [Elecraft] Interfacing Ke with MFJ929?

[Dave Fugleberg]

I use a SGC auto tuner in a similar configuration. Tuner at ground level,
40 feet of window line straight up to feed point of 130 foot doublet. TUN
PWR on the K3 is set to about 5 watts in the menu. Press and hold the XMIT
(Tune) button on the K3 and it tunes.
On Sun, Nov 6, 2016 at 7:05 PM George Kidder  wrote:

> In CONFIG menu, TUN PWR defaults to NOR, where tuning power follows the
> power knob.  But TUN PWR can be pre-set to any other value, which it
> will produce whenever the "xmit" button is held. (I have mine set for 50
> W since my SWR indicators are manual). You could use 5W or anything
> else.  Is this "automated" enough?
>
> George, W3HBM
>
>
> On 11/6/2016 6:43 PM, Dave Lankshear wrote:
> > I wonder if anyone has interfaced a K3 with an MFJ-929, used as a remote
> > tuner?
> >
> >
> >
> > One of my antennas is a doublet fed with 450 ohm ladder line.  The ideal
> > place for a tuner is at the base of the ladderline and I intend to
> > experiment with a variety of baluns to see which work best on which
> bands.
> > I have a suitable housing for the auto ATU and balun(s), which may end up
> > being switched remotely.
> >
> >
> >
> > The auto tuner can be set to an automatic mode whereby feeding a few
> watts
> > of RF will generate a tune before adjusting power output of the K3 to the
> > required level, but I wonder if this can be done in a more automated
> manner?
> >
> >
> >
> > Any help and guidance would be greatly appreciated.
> >
> >
> >
> > 73 Dave G3TJP
> >
> >
> >
> >
> >
> > __
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>
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Re: [Elecraft] JT65 ON THE KX2

[Walter Underwood]

What??? That isn’t in any spec or manual for the KX2. Why 42 seconds? 

The KX2 manual says this, on page 27:

"5.0 watts or lower is recommended in all data modes. The KX2 will reduce 
power, if necessary, to maintain a safe operating temperature.”

http://www.elecraft.com/manual/E740282%20KX2%20owner's%20man%20A5.pdf 


wunder
K6WRU
Walter Underwood
CM87wj
http://observer.wunderwood.org/ (my blog)

> On Nov 6, 2016, at 4:46 PM, Nr4c  wrote:
> 
> Check manual for digital modes using DATA A submode. Watch power out as this 
> mode has a 42 second 100% TX time. 
> 
> Sent from my iPhone
> ...nr4c. bill
> 
> 
>> On Nov 6, 2016, at 11:31 AM, Robert 'RC' Conley  wrote:
>> 
>> How is it accomplished?
>> 
>> -- 
>> May You Live Long and Prosper
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Re: [Elecraft] Interfacing Ke with MFJ929?

[George Kidder]

In CONFIG menu, TUN PWR defaults to NOR, where tuning power follows the 
power knob.  But TUN PWR can be pre-set to any other value, which it 
will produce whenever the "xmit" button is held. (I have mine set for 50 
W since my SWR indicators are manual). You could use 5W or anything 
else.  Is this "automated" enough?


George, W3HBM


On 11/6/2016 6:43 PM, Dave Lankshear wrote:

I wonder if anyone has interfaced a K3 with an MFJ-929, used as a remote
tuner?

  


One of my antennas is a doublet fed with 450 ohm ladder line.  The ideal
place for a tuner is at the base of the ladderline and I intend to
experiment with a variety of baluns to see which work best on which bands.
I have a suitable housing for the auto ATU and balun(s), which may end up
being switched remotely.

  


The auto tuner can be set to an automatic mode whereby feeding a few watts
of RF will generate a tune before adjusting power output of the K3 to the
required level, but I wonder if this can be done in a more automated manner?

  


Any help and guidance would be greatly appreciated.

  


73 Dave G3TJP

  

  


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Re: [Elecraft] JT65 ON THE KX2

[Nr4c]

Check manual for digital modes using DATA A submode. Watch power out as this 
mode has a 42 second 100% TX time. 

Sent from my iPhone
...nr4c. bill


> On Nov 6, 2016, at 11:31 AM, Robert 'RC' Conley  wrote:
> 
> How is it accomplished?
> 
> -- 
> May You Live Long and Prosper
> __
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Re: [Elecraft] Interfacing Ke with MFJ929?

[Brian Hunt]

I have a MFJ-927 which is probably the same circuit board in a different, water 
resistant box. It's powered over the coax with a bias-T. It's set up to 
automatically tune when it sees RF. I give it about 5 watts of "TUN PWR" and it 
finds a match, usually pretty easily. Sometimes it's. Little flakey and seems 
to depend on where it's tuning from. You can watch it tune on the K3 display 
and see what it arrives at. 

I use the 927 on 80-30m with a 92 ft doublet, 450 ohm window line and a 1:1 
choke balun. SWR < 1.5:1 most of the time. Helps keep the losses in 130 ft of 
coax under control. 

73,
Brian, K0DTJ
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[Elecraft] Interfacing Ke with MFJ929?

[Dave Lankshear]

I wonder if anyone has interfaced a K3 with an MFJ-929, used as a remote
tuner?

 

One of my antennas is a doublet fed with 450 ohm ladder line.  The ideal
place for a tuner is at the base of the ladderline and I intend to
experiment with a variety of baluns to see which work best on which bands.
I have a suitable housing for the auto ATU and balun(s), which may end up
being switched remotely.

 

The auto tuner can be set to an automatic mode whereby feeding a few watts
of RF will generate a tune before adjusting power output of the K3 to the
required level, but I wonder if this can be done in a more automated manner?

 

Any help and guidance would be greatly appreciated.

 

73 Dave G3TJP

 

 

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[Elecraft] P3 - utility, a question

[ANDY NEHAN]

I have the latest version of the P3 utility as downloaded from the Elecraft 
website viz 1.16.3.15. I note that it enables the creation of only 16 macros 
(the P3 can store 50 macros), and furthermore those macros don't seem to be 
saved to the P3 itself (but clearly it is a useful way to test macros). I 
installed my P3 macros using the SVGA macro capability - which itself appears a 
bit of a kludge. I successfully activate those macros using a keyboard. So I 
have achieved what I wanted to.
My questions are:
1  Am I right in thinking that the macros created using the P3 utility are not 
stored on the P3, or have I missed something?? and as a supplementary how would 
one associate those macros with an activation character?
2  Is the P3 utility regarded as being fully functional as is? or are there 
plans to enable it to achieve what the SVGA macros entry kludge does??
Andy  G4HUE 
K3, P3, KPA500, KAT500
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Re: [Elecraft] TxMon and K3 (tuner bypassed) SWR missmatch

[Fred Jensen]

On 11/6/2016 11:06 AM, Ron D'Eau Claire wrote:

Sri Jim: You must have misunderstood. You defined the rig as the 'load' so I
used your definition. Perhaps that's the problem.


I thought that too.  Jim was here for dinner last night but I forgot to 
ask him.



You are right; the antenna is usually up in the air, and some hams climb
towers to make the adjustments at the antenna in order to ensure a good
impedance match with the transmission line to minimize transmission line
losses.


Well, except mine at home.  It's an EF 80-10 wire strung along the top 
of the 6' fence.  I can "measure" the SWR anywhere on it I want to since 
I'm 6'2" tall. :-)  While its claim to fame is being HOA-proof, its 
doing a surprisingly good job on 20 and 15 this AM in SS.  Just S as 
fresh meat on Sun AM, but almost no IMI's.


If you're willing to cut a 180 deg length of low-loss transmission line 
for the band(s) in question, you can measure the characteristics at the 
elevated antenna.


But most of us with dipoles, etc., make do with an approximate match based
on physical measurements. We measure the SWR at the rig to reassure
ourselves that the SWR at the antenna is reasonable.


It it's at the minimum at the rig, it's at the minimum at the antenna 
too, even if the actual value may be different because of transmission 
line loss.


And, of course, if the rig is not equipped with an ATU, we are concerned
that the SWR at the rig is not high enough to be reduce final amplifier
efficiency and increase heat dissipation. That was the original concern that
started this thread.


Indeed

73,

Fred K6DGW
- Sparks NV DM09dn

- Northern California Contest Club
- CU in the Cal QSO Party 7-8 Oct 2017
- www.cqp.org


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Re: [Elecraft] TxMon and K3 (tuner bypassed) SWR missmatch

[Ron D'Eau Claire]

Sri Jim: You must have misunderstood. You defined the rig as the 'load' so I
used your definition. Perhaps that's the problem.  

Avoiding that terminology, if there is no reflected power at the rig, the
SWR will be 1:1. Power can be "lost" in the antenna (hopefully radiated) or
consumed in the transmission line. But, as long as there is no reflected
power arriving back at the rig, the SWR at the rig will be 1:1 no matter
what it is at the antenna. 

You are right; the antenna is usually up in the air, and some hams climb
towers to make the adjustments at the antenna in order to ensure a good
impedance match with the transmission line to minimize transmission line
losses. 

But most of us with dipoles, etc., make do with an approximate match based
on physical measurements. We measure the SWR at the rig to reassure
ourselves that the SWR at the antenna is reasonable. 

And, of course, if the rig is not equipped with an ATU, we are concerned
that the SWR at the rig is not high enough to be reduce final amplifier
efficiency and increase heat dissipation. That was the original concern that
started this thread.  

73, Ron AC7AC

-Original Message-
>
> And the losses are low. Losses go up with increased SWR on a given 
> transmission line and losses reduce the SWR measured at the load.

Not correct. And how many of us measure SWR at the load?  It's up in the
air!

73, Jim

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Re: [Elecraft] K3S USB audio questions

[Richard Lamont]

Hi,

FWIW I've done this. I've increased the gain by 12 dB, i.e. two bits.

Incidentally, the scaling on CONFIG:LIN OUT is linear - i.e. the output
voltage is proportional to the number. So for +12 dB w.r.t. the default
I've increased it from 10 to 40.

Richard Lamont G4DYA

On 06/11/16 16:48, ab2tc wrote:
> Hi,
> 
> You make a good point for some digital modes. But you should be able to make
> up for most or all of these 3 bits by increasing the LINE OUT as it must
> surely be before the codec ADC but probably not before the K3's DSP DAC.
> It's a shame that they have to do it this way (back to back DAC/ADC, but
> everybody else is doing the same). But by adjusting LINE OUT, the USB audio
> interface should be no worse than the audio LINE OUT considering the
> nonlinearity of the transformer in that path.
> 
> AB2TC - Knut
> 
> 
> 
> Richard Lamont wrote
>> On 05/11/16 18:13, ab2tc wrote:
>> [
> 4. When listening to SSB audio at S9+, with slow AGC, the output level
> via this interface seems to be -22 dBFS true peak. Why is it throwing
> away three bits of resolution? Or is this amount of headroom
> necessary/useful?
>>
>>> The audio level seen by, say a recording program on the PC depends on the
>>> LINE OUT setting on the K3. I left that as the default, 10, and used the
>>> Windows mixer to adjust the level. My audio is now reading  approximately
>>> -6dB below clipping which is probably a little high, but I have set my
>>> AGC
>>> SLP to the flattest possible setting (highest number). If you prefer a
>>> considerable slope on the AGC curve above threshold, you will need a
>>> lower
>>> LINE OUT setting. Remember that even when throwing away 3 bits, you still
>>> have far more resolution than you can use with an HF receiver.
>>
>> Consider JT65+JT9. There might be 30 or more signals within a 4 kHz
>> band, with widely varying levels. If they're all at the same level, then
>> each signal will be about 30 dB below the sum of the signals. If the
>> signal you want is 30 dB weaker than the others, then it will be 60 dB
>> below the sum.
>>
>> The data sheet shows the ADC has an SNR of 89 dB and THD+N of 0.01%
>> (i.e. -80 dB).
>>
>> If the sum of the signals is peaking to -22 dBFS true peak, than that
>> weak JT65/JT9 signal is going to be at -82 dBFS - close to the ADC noise
>> floor. Maybe getting at least some of those three bits back could make
>> quite a difference.
>>
>>
>> -- 
>> Richard Lamont G4DYA
>> 
> 
>> richard@.me
> 
>> 
>> 
> 
> 
> 
> 
> 
> --
> View this message in context: 
> http://elecraft.365791.n2.nabble.com/K3S-USB-audio-questions-tp7623845p7623862.html
> Sent from the Elecraft mailing list archive at Nabble.com.
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>  
> 

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[Elecraft] KX2 alt MD

[Greg Franklin]

A small group of us in the Pacific NW operate voice and digimodes on the
lower bands (40m, 80m) and we seem to be frequently shifting between voice
and digimodes.  It would be nice if a future firmware update removed the
necessity of the alt MD feature and put the alternate mode access in the
MODE button itself.  That way when switching from LSB voice to a USB
digimodes, it would simply be a matter of accessing a front panel button
rather then diving into the submenu for each change from LSB to USB and
vice versa.  Just a thought.
73
Greg
VA7BC
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[Elecraft] Elecraft SSB Net

[John W Webster]

Please consider joining us for the weekly Elecraft SSB Net on Sundays at 18:00z 
(UTC)
on 20m (14.303.5).  Remember that we always stay with universal time, so the 
local
time will change in places that have daylight saving time.  So today, here in 
California the 
net meets at 10am instead of 11am.

73

John, N6JW

Eric WB9JNZ, sent the following list of participants for last week:

Elecraft SSB Net 10-30-2016

WB9JNZ Eric IL K3 4017 Net Control

W4RKS Jim TX K3 3618

AE6JV Bill CA K3 2299

N4NRW Roger SC K3 1318

NS7P Phil OR K3 1826

K7BRR Bill AZ K3S 10939

W7QHD Kurt AZ KX3 8697

W8OV Dave TX KX3 3139

K4GCJ Gary NC K3 1597

K1NW Brian RI K3 4974

W4PFM Paul VA K3 1673

W2RWA Dick NY K3 2603

N2LRB Jose NY Flex 1500 QRP

NC0JW Jim CO KX3 1356

AA2RR Ron NJ KX3 1764

W7REK Glenn AZ K3 2843

KF7JZH Ron ID KX3 2262

W0CZ Ken ND K3S 10329

W4PFM Paul VA K3 1673

W4DML Doug TN KX3 2915

ZL1PWD Peter New Zealand K3 139

W5MLM Mark TX KX3 8673 QRP

K7JG John WA KX3 3519

N7GOD Gordon WA K2 6533
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Re: [Elecraft] K3S USB audio questions

[ab2tc]

Hi,

You make a good point for some digital modes. But you should be able to make
up for most or all of these 3 bits by increasing the LINE OUT as it must
surely be before the codec ADC but probably not before the K3's DSP DAC.
It's a shame that they have to do it this way (back to back DAC/ADC, but
everybody else is doing the same). But by adjusting LINE OUT, the USB audio
interface should be no worse than the audio LINE OUT considering the
nonlinearity of the transformer in that path.

AB2TC - Knut



Richard Lamont wrote
> On 05/11/16 18:13, ab2tc wrote:
> [
 4. When listening to SSB audio at S9+, with slow AGC, the output level
 via this interface seems to be -22 dBFS true peak. Why is it throwing
 away three bits of resolution? Or is this amount of headroom
 necessary/useful?
> 
>> The audio level seen by, say a recording program on the PC depends on the
>> LINE OUT setting on the K3. I left that as the default, 10, and used the
>> Windows mixer to adjust the level. My audio is now reading  approximately
>> -6dB below clipping which is probably a little high, but I have set my
>> AGC
>> SLP to the flattest possible setting (highest number). If you prefer a
>> considerable slope on the AGC curve above threshold, you will need a
>> lower
>> LINE OUT setting. Remember that even when throwing away 3 bits, you still
>> have far more resolution than you can use with an HF receiver.
> 
> Consider JT65+JT9. There might be 30 or more signals within a 4 kHz
> band, with widely varying levels. If they're all at the same level, then
> each signal will be about 30 dB below the sum of the signals. If the
> signal you want is 30 dB weaker than the others, then it will be 60 dB
> below the sum.
> 
> The data sheet shows the ADC has an SNR of 89 dB and THD+N of 0.01%
> (i.e. -80 dB).
> 
> If the sum of the signals is peaking to -22 dBFS true peak, than that
> weak JT65/JT9 signal is going to be at -82 dBFS - close to the ADC noise
> floor. Maybe getting at least some of those three bits back could make
> quite a difference.
> 
> 
> -- 
> Richard Lamont G4DYA
> 

> richard@.me

> 
> 





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Re: [Elecraft] TxMon and K3 (tuner bypassed) SWR missmatch

[Wes Stewart]

Line loss decreases the SWR measured at the source, not the load.

In this case, thinking in terms of return loss makes this thought experiment 
easier.  The line loss adds to the return loss of the load, increasing the input 
return loss by a factor of 2 X line loss (dB).  Higher return loss = better match.


While on this subject, let me introduce you to Dan, AC6LA's fabulous software 
and tutorials.  Before the death of my wife changed some priorities, I did a lot 
of beta testing for Dan after he was gentleman enough to ask permission to 
include ladderline data that I developed in his software.


For a discussion of increased loss due to SWR this is a must read: 
http://ac6la.com/swrloss.html


If you want to use a wonderful tool to help understand some of this, this 
(free!) one can't be beat: http://ac6la.com/tldetails1.html *


His Zplots tool is also useful, and free, but does require that you have some 
version of MS Excel.  If you use EZNEC, then I've found AutoEZ to be indispensable.


Wes  N7WS

* If you download and play with this tool, here are some starting values that 
are illustrative.


Set
Type = Belden 9913.
Freq = 125 MHz
R = 50
X = 0
R and X = At Load
Length = 100 feet

Results:
At the bottom of the frame click the "Return Loss"
Loss (total) = 1.5 dB (this is the matched line loss)
If you look at the "At Input" and "At Load" columns you can see that:
RL (true) is 61.238 dB and 58.238 dB respectively.  The input RL is exactly 3 dB 
greater than the load RL.  (2 X the line loss)


The true values are different from the 50 Ohm values.  This is because the line 
Zo isn't 50 Ohm as seen in the "True Zo" box. The "Plot |Zo|" and "Plot VF" 
buttons will open another screen where these values can be seen to vary with 
respect to frequency.


Return to the first screen and click Show SWR.  Change R to 1000. Note that the 
At Load SWR (50) = 20, exactly as expected. The input SWR is ~4.5.  showing that 
a moderately lossy line can have a profound effect with highly mismatched loads. 
In the loss column the total is 6.599, ~5.1 dB greater than the matched loss.
But selecting Show Return Loss again shows that the input is still 3 dB higher 
than at the load, they're just much smaller values.


If you can measure input SWR and want to know load SWR and you've characterized, 
or believe the manufacture's specifications for your matched line loss, you can 
convert the input SWR to RL, subtract 2 X matched line loss and derive the load 
RL.  Convert this back to SWR.  If you don't want to do the math, use Dan's tool 
and trial-and-error.





On 11/5/2016 12:57 PM, Ron D'Eau Claire wrote:

And the losses are low. Losses go up with increased SWR on a given
transmission line and losses reduce the SWR measured at the load.

(I neglected to make that point in my last post and couple of sharp-eyed
readers caught it.)

73, Ron AC7AC




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[Elecraft] JT65 ON THE KX2

[Robert 'RC' Conley]

How is it accomplished?

-- 
May You Live Long and Prosper
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Re: [Elecraft] TxMon and K3 (tuner bypassed) SWR missmatch

[Jim Brown]

On Sat,11/5/2016 12:57 PM, Ron D'Eau Claire wrote:

...The SWR on a line is determined entirely by the match between the line
and the load -- when we're transmitting, that's the antenna, and when we're
receiving, it's the receiver. And yes, it's same everywhere along the line
as long as the line is uniform -- that is, the same impedance, and with no
stubs or matching networks.

73, Jim K9YC

And the losses are low. Losses go up with increased SWR on a given
transmission line and losses reduce the SWR measured at the load.


Not correct. And how many of us measure SWR at the load?  It's up in the 
air!


73, Jim

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[Elecraft] Elecraft CW Net Announcement

[kev...@coho.net]

Good Evening,

   The sun has been active this week.  So active it made a lot of 
noise.  However, after that calmed down signals were better than they 
had been in a while.  DX kept popping up like the local chanterelles.


   While clearing out an acre of hillside I flushed a grouse. That is 
not uncommon.  But, instead of flying into the nearby thicket of alder 
he perched on a limb.  For the next half hour he watched me improve his 
bit of property.  The bear berries will do nicely next year.  Once he 
was satisfied with my work he glided off.  The elk have already approved 
my work.


Remember the time change.  Local time stays the same (for most of you) 
while the UTC time changes.  If the bands are uncooperative there may be 
changes.


Please join us tomorrow on:

   14050 kHz at 2300z Sunday (3 PM PST Sunday)
 7045 kHz at 0200z Monday (6 PM PST Sunday)

73,
Kevin. KD5ONS

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