I just finished putting together a K3, I've looked at the
manuals, and I have a question.
I have identical filters in the main and second receivers.
Stock filters plus FL2 2.1kHz and FL3 400Hz.
How do I know the roofing filters in the KRX3 are being
selected? Are they automatically
The KRX3 manual explains how to set parameters on the
second receiver,
including filter settings. The manual is available on the
Elecraft web
site. The quick answer is to use the BSET hold function
on the front panel
to configure settings in the second receiver and SUB to
enable the
For the benefit of W8JI ... saturation is a good description
of
the behavior. When adjusting the Line Out level above 1V
peak,
any single tone in the audio spectrum appears to be clipped
at the 1V level. Although this could be due to clipping in
the
audio amplifier, given the manual warning,
It's a 600 ohm transformer, rated for 7dBm max (about 1.7
Vrms across 600 ohms).
Bob NW8L
But that doesn't mean it distorts or saturates. It is
simply a rating.
My K3 for example on a good Agilent selective level meter
starts to distort at -5dB reference to 1 milliwatt into 600
ohms.
Most hams know that the standard BNC (not the mini
version)
should handle 200-300 watts and not be pushed higher, altho
likely will go
higher for some time.
The BNC, either 50 or 75 ohm, is dimensionally almost
identical to the 50-ohm style type N connector. As a matter
of fact we use BNC
It's what us humans do. And that's why so much effort is
put into making
truly objective observations. That's very hard for humans
to do, if we are
able to do so at all.
Ron AC7AC
Amen. The whole purpose of the scientific method is to
try to eliminate
scientists' subjectivity from their
It is true that the AGC pertains to the radio and not the
band, but the optimal AGC threshold setting does vary by
band. On 80m, for example, I set the AGC threshold on my
Ten-Tec Orion at about 20uV. On 10m, where the noise level
is very low, I set it at 0.5uV. The Orion, incidentally, has
- if I set my power level at 5W my CW key-down output
power will actually be
5W
- if I set my power level at 10W my SSB PEP output power
will actually be
10W (avg power somewhat less)
...or relatively close to this. Right?
If SWR is very good.
To get the true power with a load mismatch
I had previously posted some RF Current data using an
MFJ-835 Balanced RF
Current meter. I measured the amount of current flowing
in each side of my
ladder line
I'm pretty sure that unit doesn't actually indicate balance.
I'm pretty sure it only indicates equal currents by sampling
scalar
There is only one AUX input physical connection on the
KRX3. At assembly, one must select which, if any, aux
input source will be used... either the non-tx KAT3 ant or
the separate BNC connector. That necessitates the
selection of Ant=bnc or Ant=Atu . When I installed the
KRX3, I physically
how did you bring them out? did you run then through some
existing hole?
I made a plate that bolts into the normal RX antenna and
transceiver antenna interface area.
___
Elecraft mailing list
Post to: Elecraft@mailman.qth.net
You must be a
The figure referred to is using the material as part of an
RFI suppression choke where you want attenuation at RF
frequencies. I think you'll find that when the Type 61
material is used as a transformer, it will have very low
loss if designed properly.
Even 73 materials can have low loss if
I didn't think is was LEGAL to transmit music, tones or
even whistle for
that matter.
Tones are legal for specific purposes like adjustments.
It's easy to adjust normal SSB to proper tuning by listening
to the voice. Voices contain harmonically related
frequencies that sound odd (out of
I heard some one say that a balanced tuner is very
expensive to build. I used some quarter inch copper tubing
from the hardware store to build a four inch coil. This is
the tubing for a ice maker. I then built a four inch coil
and tapped it to a multi position switch from radio shack.
I had
How about a normal L-type network? Connect one side to the
balanced
line, and the other side via a current balun to the 50
coax. The tuner
is 'RF-floating'. (You can run the coax through a toroid
or use two
seperate wires to make the current balun.)
Arie,
Respectfully that does not work at
So, Tom, how would you comment upon a transistorised rig
of 50 ohms impedance unbalanced output connected to an
unbalanced pi configuration antenna coupling unit
(variable C1 between input and ground, variable series L
in the hot lead, and variable C2 between output and
ground) followed by a
Probably true of the 1:1 configuration, but not of the 1:4
configuration. If you analyze the latter in terms of
chokes, you have a choke connected across the differential
signal, so if the differential impedance is high, most of
the current would bypass the antenna.
Why would anyone ever
Actually one might put them on the input, in the sense
that one might
have a balanced feeder at close to 200 ohms and a balanced
tuner at the antenna end. That's probably the only case
in which they would work well.
The basic rule still applies. We can't move any balun to the
input of an
Having, in waiting for my K3, read all sorts of accolades
for the NB and NR,
I feel, now that I have the radio in front of me, somewhat
deflated. The NB
is, it seems to me, no better than many others I have used
(eg TS-850) and
the NR does not seem, to me at least, to be any better
than that
That's important!
ICE says that they will work with impedances of 300-600
ohms. Although the characteristic impedance of a line may
be within this range, the impedance *seen* at a particular
point could be very high or low.
Multiply line SWR by line impedance. Most ladder line is
around
This is a particular problem with transceivers that have a
single V- lead and only one pin for the V- connection
(like
the K3). If the negative lead connection is not
absolutely
perfect other ground paths (e.g. the shield on a
microphone
cable) through accessory equipment will carry a portion
The obvious solution is just to use the K3 +12VDC output
connector for
all accessories. It's rated for 0.5A which should be
plenty for most
devices. As a bonus it's controlled by the K3 ON/OFF
switch.
That by itself doesn't cure ground loops and it doesn't cure
the negative lead damage
It actually doesn't matter beyond about 30 dB down
ina roofing
filter...the DSP filters handle things beyond that.
Two points are entirely
sufficient to **center** the filter's 6 dB bandwidth,
which was the
question
asked.
I don't think -6dB bandwidth was the question, but rather
Again, the noise isn't from the charger ... it's generated
along the wire. Carrying an AM radio along the fence may
be helpful and is useful in illustrating to the fence
owner what
you're talking about. He/she may already be aware of the
noise and not know the source. (:-))
While it is
This seems to have been seriously mangled by a journalist.
As written it is suggesting that we are at a sunspot
maximum and that the effects of sunspots are detrimental
to HF amateur radio. We are actually at a sunspot minimum
and, whilst sunspots may increase unpredictability they
also
Given a 100 KW transmitter, with 2nd harmonics 40 dB down
from the
fundamental (which would be considered reasonably good
suppression) is still 10 watts at the 2nd harmonic,
I'm not sure about Europe but the Amateur radio *minimum*
standard at HF for 1500 watts is about 45dB down for any
I am consummately pleased with my K3. I am astounded
with the raw
performance and dazzled with the features.
So am I.
The K3 is the first radio I have ever bought without some
silly engineering shortfall. The only things I see people
complaining about are specialized personal use or
One thought. If you're going to operate SO2R and run
power, you should
probably use the bigger coax for the jumper, because the
more robust shield
can help interstation crosstalk. I did that in my shack
for that reason, and
it made a difference.
I'd be very surprised if that had
I do have an HP 3590D spectrum analyzer sitting in the
shack, and put a
simple loop on it to look at 2nd harmonics from my Ten Tec
425 amp and 160M
vertical. It was about -44 dBc when I started, and I got
it down to the rated
-50 dBc by doing nothing more than changing coax jumpers.
Hi Jim,
I gotta get back to work but..
More likely you changed the impedance presented to the
tank
circuit on the second harmonic.
The coax I was changing was between the K3 and the amp.
When we measure a change in a complex soup of interactions
and fields formed by the interactions, we
Isn't there a high and low gain setting, besides just the
numerical gain??
:-)
- Original Message -
From: Stewart stew...@baker.nildram.co.uk
To: Jan Erik Holm sm2...@telia.com
Cc: elecraft@mailman.qth.net
Sent: Friday, June 04, 2010 10:23 AM
Subject: Re: [Elecraft] K3 with Heil HC-5
Does anyone have any experience with trying to match one
of these 43-ft
verticals, that are being offered by several
manufacturers, using the K2s
internal ATU? Is it able to find a match on 80-meter CW?
Are there any
particular brands of 43-ft verticals that you like or
don't like?
Yes it is the possible effect on the input L-C circuit
that is my main
concern.
73,
Geoff
GM4ESD
I would think the major concern would be elevated noise or
change in the first stage's semiconductor device parameters
from the receiver's input device temperature increase, not
from tuned
Would that not depend on whether or not the source
impedance presented to the input device has been optimised
for lowest noise figure or for optimum power transfer? If
the former then the question arises how rapidly does the
noise figure change with small deviations from an optimum
Well I wouldn't say useless. I'm sure no recording is
*exactly* like the
original but I have often played back another station's
transmission (eg to
help them set up their audio to let them know how they
sound over a long
distance), and other people listening (eg in the same
net)
The base loading coil is nearly identical in design to the
toroidal
coil of AD5X, linked below. I do intend to find 160 80m
tap
locations for the antenna.
I hope you have serious top loading.
I have a video of a base loading coil throwing a two inch
long arc when running 500 watts on
Elecraft. A lot of guys speak negatively about this
antenna design and
show all the reasons it shouldn't work. All I can say is
it works for
me.
Hi Phil,
Works for me is fine. No one can argue with that. That
doesn't mean it has reasonable efficiency. If it had
reasonable efficiency, it
Pete,
I take hits directly on my towers all the time, and I never disconnect the
K3 or any other rig. Of course my closest tower is about 150 feet away, so
this might not work if you get a hit just feet away where the EMP is huge,
but a good system will significantly reduce chances of a
Don and all,
The 88 foot dipole, and the 44 foot dipole, are examples of an antenna
designed for pattern alone with no consideration of feedline losses or
matching systems.
http://www.w8ji.com/short_dipoles_and_problems.htm
With an 88 foot antenna the 80 meter SWR on a 400 ohm line (most
With the 80 meter coil option on the BigIR, you could see higher SWRs on
15
through 6 meters in the normal 1/4 wave mode. SteppIR recommends using
the
3/4 wave mode for those bands. This may help.
.with everything but wave angle
:-)
The low-band TV signals are all QRT now, so that shouldn't be an issue
anymore. There is only one VHF high station in range for me. I think it is
up around 200 MHz.
- Original Message -
From: ka9zap ka9...@wowway.com
To: K3 list Elecraft@mailman.qth.net
Sent: Sunday, June 13, 2010
The most important thing in this is to always have a dc leak path to earth
on the antenna side of any T network or anything else that might add a
series capacitance. (Some lighting suppressors are a bad design with dc
isolation by a series capacitor on the center conductor.) We never want
Stan,
I had some weird stuff happen with my K3 on SSB when I accidentally offset
the filter incorrectly. Almost like what you have, but perhaps not quite so
bad. I was really puzzled why filter offset affected ALC so much. That's all
I corrected and it cured my problem.
73 Tom
-
It begs the question what we should do with the 1000s of LP filters out
there. Some are built very well, like my Drake, but I also have a couple
made of bent tin. There was a QST article on them a few years ago
showing
different construction styles and quite intriguing how costs could be
This topic greatly interests me, because I have never found saturation or
non-linearity in typical cores an issue.
This might be an opportunity to explore something new that I have never
seen.
- Original Message -
From: David Cutter d.cut...@ntlworld.com
To: Geoffrey
Hi Jim
If you are interested in the details of AM you can read it here:
http://www.w8ji.com/amplitude_modulation.htm
Since the ratio of peak power to carrier is 4:1 in a symmetrically modulated
AM signal, the carrier power must be 25 watts or less with a 100-watt PEP
radio. I'm sure the K3
What is the noise figure of the K3 on six meters?
On SSB bandwidth I barely hear a noise increase when I switch from a dummy
load to my antenna.
73 Tom
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
The theory in that link is pretty far-fetched. The screen is an excellent
shield for RF between the anode and grid. If the screen wasn't a nearly
perfect RF shield, we would never be able to use the tetrode in a grid
driven amp.
It's silly to think the screen shield the control grid for months
Well heck if LMR400 is .7dB/100ft I'm not so sure that its worth mucking
with finding adapters for it as if I end up having to put 2 adapters on
each end to get it to something I can use there goes most of my
advantage of stepping up from LMR400 to LMR600...
The loss in connectors or
Brett,
No one can answer that question for you, because both antennas are
unpredictable in nearfield performance. Also the layout of the antenna and
what is around, under, and between the antennas is very important.
With such a large soup of unknowns, plus there might be other transmitters
on
feedline radiation, and as such will be unpredictable
in polarization tilt with direction and elevation.
This all would be better on an antenna forum, so this is my last comment.
:-)
73 Tom
--- Original Message -
From: Brett Howard br...@livecomputers.com
To: 'Tom W8JI' w...@w8ji.com
Almost 30 years ago, when I designed the AL1200 amplifier, it included a
rough relative voltmeter like most other amps had except I included a
cheap peak voltage detector.
I thought I'd calibrate the cheap relative voltmeter scale, making the scale
show peak watts instead of zero through ten
We had one guy get on 75 with a KW with another on 40. Guy on 40 didn't
know. He got the RFI warning, the K3 locked up and he smelled smoke. Now
his K3 has no RX at all. I thought there was a high power protection
circuit? We have other rigs to use but any input as to what needs to be
We sort of got sidetracked from the original posters remarks. It's about
low
headphone level on the K3. If the level were a bit higher there would be
no
need to plug the headphones into the speaker jack. Similarly each pair of
headphones you grab seems to have a different level. I have 3
- Original Message -
From: Grant Youngman n...@tx.rr.com
To: Elecraft Email elecraft@mailman.qth.net
Sent: Monday, June 28, 2010 10:29 AM
Subject: Re: [Elecraft] Power Poles...
It would also be simple enough for the manufacturers to solve the polarity
problem by using a bridge
the
darn thing to avoid disasters like plugging a 24v supply
into a 12v radio? :-)
Grant/NQ5T
On Jun 28, 2010, at 10:38 AM, Tom W8JI wrote:
- Original Message - From: Grant Youngman
n...@tx.rr.com
To: Elecraft Email elecraft@mailman.qth.net
Sent: Monday, June 28, 2010 10:29 AM
Every operator cranked the K3 output to max (110W output) could not
get them to leave it at 100.
I don't know why hams are so uneducated about that. At least 110 watts is
not as bad as what someone I know does with his contest FT1000MP's and other
100W radios. He runs them at 130 watts or
So the K3 has a fully floating ground on the line audio input, isolated from
the chassis??? Is that correct?
73 Tom
- Original Message -
From: Edward R Cole kl...@acsalaska.net
To: Elecraft@mailman.qth.net
Sent: Saturday, July 03, 2010 4:08 AM
Subject: [Elecraft] WJST and the K3
Heck a lot of the current quality DMM's will take this in stride... One
of the tests we do when demoing meters (and I've seen it done commonly
from reviewers) is to run a meter through the different feature settings
while connected to the mains. Often we'll just dump the probes into the
That's what I had to do Pete. The bail is far too tall for me also.
After trying to whittle wood and bend metal, I finally cut some dense closed
cell foam on my band saw and made a nice little riser for the front.
73 Tom
Thanks! The current one only elevates the frot bottom edge of my K3 2
The typical cost to take a parts order and ship a part at Ameritron, back in
the 1980's, was about $20. That does not include the shipping fees, just the
overhead to take an order, pick the part, pack the part, and do the shipping
labels, handle the invoice or paperwork.
Shipping small low
Ameritron makes an RCS12 control head that I use here. I have about a dozen
of them in use.
It not only is programmable as to the allowed output ports for a radio's
band data input, it also works as an antenna switch controller and will lock
out the wrong antennas on the wrong bands. It
There are three types of HF and 160 meter fading I can identify.
1.) Normal ionospheric fading
2.) Fading caused when wide-spaced antennas are directly combined, making a
very sharp pattern. The signal, as arrival angles change, moves in and out
of pattern nulls.
3.) Multipath.
Number 2 is
Hi David,
The Beverage and the vertical are both vertically polarized.
A single vertical is a very broad pattern with much less directivity than a
Beverage. Since for receiving signal-to-noise is closely tied to directive
pattern and not gain or antenna type, the vertical will have
Hi Craig,
You said:
I recently installed the sub RX and plan to use it
for CW contesting.
When running, I like to use Split with the xmit freq on VFO B. I then
tune
the calling stations, if required, using VFO A. I normally use a fairly
wide BW (300-500 Hz) to avoid much tuning on
I'll probably get lynched for saying this, but for my ears I've never found
a DSP system that is as good as a pure analog system when there is rough
noise. The K3 is much better than my Orion I, but I strongly prefer full
analog IF's with rough noise or when a signal is right at noise floor and
The Johnson T-R switch came in two iterations, as I recall. The first
one suffered from suck-out, as did the second, but less so.
Signal suckout occurs because the tank circuit in the transmitter presents a
low impedance when the tube end of the tank is misterminated during key-up
(resting
It will sound great if you add a J310 or similar JFET source follower. Very
flat clean response.
A source follower is very simple. Use a low voltage .01 uF or .05 uF disc
cap to the gate. Use a 100k to 1 meg ohm resistor from gate to ground. Put a
560 ohm source resistor to ground, and couple
as a
voltage source.
:-)
- Original Message -
From: Jim Brown j...@audiosystemsgroup.com
To: elecraft@mailman.qth.net
Sent: Saturday, July 10, 2010 12:20 AM
Subject: Re: [Elecraft] D104 mic
On Fri, 9 Jul 2010 20:47:36 -0400, Tom W8JI wrote:
It will sound great if you add a J310
I want to report the stunning success the PT-3 has had on the upper
bands. Especially 15 and 10 meters. I have long held the suspicion
that the K2 is deficient in sensitivity on these bands and the PT-3
confirms it in spades. Stations that are indecipherable now stand
out clearly in arm
Definitely iconic - the D-104 was the overwhelmingly first
choice of the out-of-band-and-overpower CBers for use with
their modified Yaesu FT-101E transceivers in the 1970s. Some
of those folks eventually saw the light, got their ham
licenses, abandoned CB, and became good hams.
My
have my beverage connected to the RX ANT IN and I can transmit into my TX
antenna while RX ANT is turned on without problem.
I tried to connect my 40 mts yagi to RX ANT IN because it was listening very
good, but I hear a continuous clicking, like a relay. What´s that? Why with
one antenna is OK
This is almost certainly thermal drift from heat.
seem OK, the power from driver and the power output remain stable
during key-down, but the current increases...
What could be the issue?
Before spending more time on troubleshooting, has someone had and
solved the same problem?
Poor
Does anyone have experience with the amplified D104?
Dick, KA1SA, #911
I cut those boards out of mine, except for the PTT switch mounting. I prefer
something more simple and easily controlled.
__
Elecraft mailing list
Home:
I made an even more cost-effective one: I put a couple of diodes in
parallel (anode to
cathode) across the connector in the old coax switch I use for receiving
antennas. I wrote
FOR RECEIVE ONLY! on the switch in big letters.
I can't do that here Vic because on most of my antennas the net
When the antenna is connected and disconnected the noise floor moves just
barely. You can tell, but it requires a critical ear.
That is too little. That is about how my K3 behaves on six meters on SSB
bandwidth! On the narrowest bandwidth you use, you should hear a very well
defined noise
I was using a sloper for 160 mts from a 118ft tower and the 40-2CD was on
top of this tower.
So I couldn´t connect the 40-2CD in the RX ANT IN.
So I switch the knob in my sixpack to listen in the 40 and then switch again
to TX on the 160 antenna, hope this will not cause a problem in the rig?
Hi Vic,
So the voltage produced by the receiving antennas is relatively low. I
agree that it wouldn't work with a resonant antenna.
On my Beverage antennas (which are low gain) the accumulation of AM BC
signals, SW BC signals, and so on at night is enough to light the filament
of a 12 volt
Seems is similar to this made from ICE, at least will add extra protection
to the K3, what do you think?
Or it will decrease the RX signals I can receive in the K3?
As far as I know that unit uses reed relays, and should have no detectable
loss. I think there might be two models of that,
I would have no use for a 750 Hz filter. 99% of the time I use SSB bandwidth
on emty CW bands, or less than 500 Hz BW.
I have my filters set so the 500 Hz roofing kicks in at 600 Hz BW, my 250
roofing in at 350.
This is in an attempt to soften the big 50 Hz selectivity steps when using
narrow
FWIW I have a Perseus and two other receivers which both use H-Mode mixers,
one of which uses a version of PA3AKE's H-Mode front end.
With the Perseus used as a stand alone receiver, I have not experienced
this
noise problem in the presence of mild or quite strong static or manmade
pulse
Personally, I would prefer that the s-meter not operate in this way in
ABS mode. RF Gain should have no effect on the s-meter action when in
ABS mode, just as ATT and PRE do not.
It would probably screw up (highly technical term) how the system works, or
require a separate receiver just for
Regardless of the fact that in 1934 (as was indicated to me in off
reflector email) we used to not use the meter for the S report, at some
time (1970's when proper calibration and standardizations' came about) we
were able to shift that OLD antiquated 1934's definition over to a
My concern for any Switching supply is the RFI noice that the radio will
pick up
from the power supply. Looking at the SEC 1235m, I was reading that it has
a
build in RFI filter. Plus I like the AD5X mod to slow down the fan. And
the
Alinco DM-340 MVT has a knob to change the freq. of
These measurements are QUITE valid, and represent the response of the
radio
from antenna input to audio output. The wide and narrow measurements on
the
same page are the same data, plotted to different scale -- the narrow
plots
to show filter bandwidth, the wide plots to show behavior
Yes, think about this using common sense. Assuming typical band noise
might
typically be -120 to -130 dBm, and the internal noise floor of the radio
is
-137 dBm, you cannot expect to measure 60-70 dB down from such a low level
noise source without running into internal noise floor
I've been thinking about how one might go about adding some protection
for the apparently fragile (and expensive) RS-232 port on the K3. It
might be possible, if the components were small enough, to add them on
the KIO3 I/O daughterboard, or perhaps on a little external board
mounted at the
Can someone give me a short answer as to why Win-Test was the
overwhelmingly popular logger, especially versus N1MM?
Probably because it emulates CT (DOS) which most contesters are very
familiar and comfortable with.
Exactly. That's why people like it, and it networks easy. Unfortunately it
This is absolutely the single most important thing to do
In addition, bringing all lines into the station (including AC mains
power, telco, LAN as well as antennas, rotor cables and control lines)
through a single point grounding panel which has protective devices
installed on each and
Consensus seems to be that grounding, particularly making sure that all
chassis are bonded together with the station entry panel and the
powerline ground, is the best protection. I think this likely is where
I went wrong, because I had just completed the radio and had not yet
grounded it to
On 7/20/2010 12:01 AM, Don Wilhelm wrote:
...so if you wish to
protect your K3 correctly (along with all the other equipment in your
hamshack), install some good lightning protection - single ground point
entry point for ALL lines coming into the hamshack - NO exceptions -
ethernet, telco,
I rarely disagree with Jim on audio issues, but I am going to disagree with
this:
On Tue, 20 Jul 2010 09:38:23 -0800, Edward R Cole wrote:
The only dc-isolated wiring in my shack is the soundcard audio lines
from radios to computers.
Jim replied:
Why are these isolated? They should NOT be. See
IN addition to bonding my radio ground rod to the electrical ground
(on the other side of the house), I will have my radio ground going
to my cable entrance plate. From there I have two tables and my
racks arranged in an U configuration with radio table facing the
racks six feet across the
In the traditional sense, LINE was a broadcast and
recording industry standard for FIXED signal at 0dBm, and
600 ohms. It was used to interconnect various pieces
equipment and was supposed to relieve the engineers of the
need to determine what the signal level was and what the
source and
Interesting. I run a K3 off a couple of pseudo deep cycle 12 volt
batteries with an Iota smart charger hooked up. I run mostly digital
so IMD is important to me. The Iota runs between 13.1 and 13.6 volts
by my K3's meter. Would the difference between that and 14 volts make
a meaningful
In some connector applications ... particularly power
dividers and other applications that are impedance-
conscious ... SO-239 / PL-259 connectors are not
suitable.
This is NEVER the case at 30 MHz and lower, so long as connection to the
connector are properly done. The total impedance bump
Makes sense on the teflon insulator... I assume that that only makes
the difference when doing higher power?
It mostly makes a difference in soldering. The measured voltage breakdown of
a standard Amphenol SO-239 is well over 5000 volts peak. The arc point is
normally the air gap between the
insidebut I do think that the issue with standard mud type UHFs is
with the durability of the dielectric, not with the impedance bump, at
HF and even low VHF frequencies.
That's an accurate statement John. The largest bump I've even measured with
a SO239 PL259 pair was about 1.05:1 at
So I've looked at a few sites describing how to make a 4:1 balun... One
such solution is to take 2 100 ohm 1:1 baluns and connect them in
parallel on the input side and in series on the output side...
The 100 ohms is the differential impedance, or transmission line impedance,
NOT the choking
While this is true I still feel that any KEY_IN source be it PTT or VOX
or the paddles it should interrupt the memory keyer.
Makes total sense to me. Any call for another transmission source, VOX, PTT,
external key line input, or paddles, should halt automatic transmissions.
1 - 100 of 244 matches
Mail list logo
