Chris
Is the frequency separation exactly 900 kHz? If a bit more, perhaps the
oscillator in the KSB2 MCU (U1/Z1) at (nominally) 4 MHz is coupling into the IF
(nominally 4.915 MHz) path on the same board, on the output side of the crystal
filter). Problems with grounding, bypass capacitors
A few of us are planning an multi-operator operation for next weekend's CQ WW
VHF contest, cobbling together equipment from different places. I am wondering
if there are any potential issues (most likely with switching timing) with the
following potential setup for six metres:
Radio: K2
I took the front panel and control boards off the RF board and reassembled
themthe intermittent lack of response to tuning knob returned after a
couple of minutes.
So I tried Don's first couple of steps (reflowing solder on encoder lead and
front panel board U3) and that seems to have done
panel
U3 as well as P1, RF Board J7 and Control Board P2. Also reflow Control
Board U6 pins 8 and 16.
73,
Don W3FPR
On 6/10/2019 9:09 AM, Steve Kavanagh via Elecraft wrote:
> One of my K2's has developed a problem where it is (somewhat intermittently)
> unresponsive to turning the tunin
One of my K2's has developed a problem where it is (somewhat intermittently)
unresponsive to turning the tuning knob. Turning the knob may or may not, at
different times, cause the radio to change frequency. Pushing on the
case/panels and tapping the tuning knob sometimes seem to help, so I
If Elecraft had a rig that was an update to the K2 (same size box with no jacks
on the sides, and all in one box unlike the KX3+KXPA100) with the following
features, I'd be interested. I find the form factor of the K2 ideal for a rig
that wears many different hats in the shack and portable.
I was experimenting with an external 120V AC fan to improve the cooling of the
KPA100 during CW Sweepstakes this past weekend. The cooling worked fine but
the fan caused some hum on received signals (and presumably my transmitted
signal as well). Placing the fan towards the right and back
traction.
I routinely now see FT8 signals on 50.313, 50.323 and even 50.333 at times when
the band is open over the Atlantic.
Mike va3mw
On Sat, Jul 7, 2018 at 6:43 AM, Steve Kavanagh via Elecraft
wrote:
Mark
As you may know, WB5JJJ suggested using a separate frequency on 6m for contest
mode
Mark
As you may know, WB5JJJ suggested using a separate frequency on 6m for contest
mode FT8, and leaving 50.313 for those running normal FT8 format. I tend to
think this might work out fairly well, but it didn't gain much traction on the
WSJT group where he posted the suggestion.
But this
My old HP supply is marked 18.5V 3.5A. My wife's newer HP is 19.5V 2.31 A.
The two DC plugs are very different (not sure how to specify them). that could
be an interesting product. Mind you, experiments have shown that my laptop
creates a bit of RFI from every port (USBs, audio etc.) and
I made some measurements on my K2/K60XV. It seems the bandpass filter does cut
off just above 28.8 MHz and the available 1 mW output from the K60XV drops
markedly starting around 29 MHz. It would not be practical to use this output
unless the bandpass filter were retuned.
At the QRP antenna
.
Thanks for your info.
73,
Steve VE3SMA
On Sat, 5/19/18, Dave Sublette <k4to.d...@gmail.com> wrote:
Subject: Re: [Elecraft] [K2] Using the K2 above 29 MHz
To: "Steve Kavanagh" <skavanag...@yahoo.ca>
Received: Saturday, May 19,
ecraft] [K2] Using the K2 above 29 MHz
To: "Steve Kavanagh" <skavanag...@yahoo.ca>
Cc: "Elecraft Discussion List" <elecraft@mailman.qth.net>
Received: Saturday, May 19, 2018, 2:12 PM
I have
used my K2 with a DEMI 2M transverter board in it to drive
transverter
The K2 is specified to operate on 10m only up to 28.8 MHz. While contemplating
possible future VHF rigs for a multi-operator multi-band environment, I have
wondered about using a K2 as an IF for VHF transverters at around 29-29.4 MHz
(to avoid interference with bands using 28 MHz IF).
Both of
There's been several good points made about my K2 internal 2m transverter
project...here's a bit of my thinking about why I went the way I did:
(1) Using an alternate transverter (VE3SYB) - I did consider the Transverters
Unlimited board from the Ukraine to potentially give me more output, but
For a while now I've been working on a project to install a low power 2 metre
transverter inside an Elecraft K2, in order to use it as an IF transceiver with
transverters for the microwave bands. I got it done this summer and used it on
10 GHz during the ARRL 10 GHz and Up Contest, as a
Phil
One possible way to make a decision is to consider whether or not you might
want to try meteor scatter on 2m using MSK144. The recommended absolute
frequency accuracy for that mode is 25 Hz (though I think you'd get away with
80 Hz). This is a real challenge at 2m and the XV144 isn't
I was wondering if anyone had tried doing the reference oscillator frequency
calibration for a K2 without the rather troublesome step of accurate
zero-beating by feeding the 500/600 Hz audio tones from WWV/WWVH to a computer
sound card or smart phone spectrum analyzer, or similar program? It's
Thanks, Wayne. Very tempting!
73,
Steve VE3SMA
On Sun, 9/3/17, Wayne Burdick wrote:
> Can anyone confirm that the dimensions match?
They do. It’s the same size as our MH3, used with the KX2 and KX3.
> Has anyone tried
I find the MH2 a bit on the large side for my hands, so the MH4 looks
interesting to me. The case appears to be identical to the Icom HM-36,which I
use with one of my K2s and find very comfortable to hold.
Can anyone confirm that the dimensions match?
Has anyone tried out the MH4 for
On Tue, 8/15/17, Don Wilhelm <donw...@embarqmail.com> wrote:
Subject: Re: [Elecraft] [K2] Sensitivity Spec
To: "Steve Kavanagh" <skavanag...@yahoo.ca>, elecraft@mailman.qth.net
Received: Tuesday, August 15, 2017, 8:29 PM
Steve,
Typically, the receiver i
I'm just trying to evaluate if I have the gain distribution right for a K2 used
as an IF for a 10 GHz transverter, through a 2 m transverter mounted inside the
QRP top. The K2 manual gives a specification for the MDS but fails to define
the bandwidth at which it is measured. Sherwood's
This one cropped up just today, with no significant change in my home station
setup, using a K2/100 on 40m using a low inverted Vee.
Sometimes (typically every other or every third time, but randomly), when
pushing (and holding) the tune button with the power set to 11 watts or more, I
get a
Initial testing using the two-MOSFET circuit
(http://www.mmccs.com/mmarc/n0ss/k2_t-r_rly_drvr.pdf ) with two 2N7000s, but
with R3 removed, indicates that it is working fine, switching a load of about
50 mA at 12-13V. I left R2 in.
Thanks all for your comments.
73,
Steve VE3SMA
Thanks, Don. Good point re the input side...I guess I'm not used to having
plug-in boards in mind!
Yes, I was thinking of a pair of 2N7000s - they are fine for the current and
voltage I need to switch.
73,
Steve VE3SMA
__
I'm planning to add an external amplifier/transverter keying circuit to one of
my K2s. I found two versions on the web, both apparently designed by N0SS
(SK). The one on the Elecraft site
(http://www.elecraft.com/Apps/Amp_keying_ckt.htm ) appears to be his original
circuit, using a 2N7000
Here's something that may be of interest to solder-minded K2 owners pondering
filtering options. I've built and installed a KAF2 kit with several component
changes to make it a little wider in bandwidth, so as to be more useful in
general CW operating, scanning the bands and contests rather
Once again Yahoo and mailman between them have conspired to mess up my link!
Let's see if I can make it come out right this time:
http://www.qsl.net/ve3sma/ModifiedKAF2.pdf
73,Steve VE3SMA
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Home:
The usual K2 headphone jack failure results in the speaker going dead. To fix
it requires replacing the jack, but a workaround is to short two pads together.
The speaker will then run all the time, whether or not there are headphones
plugged into the front of the rig. The speaker can be cut
Hmmmmailman and Yahoo between them have managed to mangle the links...they
should be http://www.qsl.net/ve3sma/downloads2.html , while the photo itself
is at http://www.qsl.net/ve3sma/K2HeadphoneJackSwitchBypass.jpg . Hope that
works better. Steve VE3SMA
Thanks, Don. Shorting those two pads together with a screwdriver brought the
speaker back to life, confirming the standard failure. Now I can decide what
to do about it! 73,Steve VE3SMA From: Don Wilhelm d...@w3fpr.com
To: Steve Kavanagh skavanag...@yahoo.ca; elecraft@mailman.qth.net
...@embarqmail.com
To: Steve Kavanagh skavanag...@yahoo.ca; elecraft@mailman.qth.net
elecraft@mailman.qth.net
Sent: Friday, June 26, 2015 7:57 PM
Subject: Re: [Elecraft] K2 headphone jack pinout ?
Steve,
An examination of the headphone jack connections in the K3 schematic
should answer your question
I think one of my K2s has suffered the dreaded headphone jack failure (no
speaker or speaker jack output - headphones work fine). To confirm this
diagnosis (and perhaps to make mods to prevent it happening again) I'd like to
get my hands on the pinout of the headphone jack J2. I was surprised
To: Steve Kavanagh skavanag...@yahoo.ca; Elecraft@mailman.qth.net
Elecraft@mailman.qth.net
Sent: Tuesday, March 17, 2015 5:42 PM
Subject: Re: [Elecraft] Audio Levels for WSJT on K2, etc.?
Steve,
On the K2 with any data mode, run the audio up until you see one ALC
bar, and then back it down until
I'm starting to play a bit with JT65 on HF (using WSJT-X) with my K2 and
homebrew interface hardware. The frequency response of the K2 seems reasonably
flat, but occasionally I see power dropouts when the tones change. This is
despite always hitting the requested power at any audio frequency
I forgot to mention that I am using RTTY(reverse) mode with SSBA = 2 and SSBCr
= 1-1. Do those settings make sense? Steve VE3SMA
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Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help:
I have recently acquired a used K2, my 2nd (S/N 5133). I am just wondering
what it would take to install the KPA100 from my older (S/N 4509) K2 in the
newer one and keep it usable with the old one too. I have been perusing the
KPA100 manual (current version) and it appears to me that all I
Thanks, Don. Sounds pretty straightforward. I'll make a point of adding that
to my K2 to-do list! 73,Steve VE3SMA
From: Don Wilhelm w3...@embarqmail.com
To: Steve Kavanagh skavanag...@yahoo.ca; Elecraft@mailman.qth.net
Elecraft@mailman.qth.net
Sent: Wednesday, February 25, 2015 7:09
In the remote chance that someone else is tracking down a similar problem, I
eventually tracked this issue down to a bad solder joint at R94 (in the
transmit buffer circuitry). Thanks to Don, W3FPR, for his (now legendary)
assistance! 73,Steve VE3SMA
From: Steve Kavanagh skavanag
it would probably
be ok to leave it unconnected, but I'm just reviewing my options. 73,Steve
VE3SMA
From: Don Wilhelm w3...@embarqmail.com
To: Steve Kavanagh skavanag...@yahoo.ca; Elecraft@mailman.qth.net
Elecraft@mailman.qth.net
Sent: Tuesday, February 10, 2015 6:30 PM
Subject: Re
I was given a DEMI TIK2 transverter interface board which I would like to
install in a K2. It requires the 8T signal on pin 6 of J13 on the RF board,
which was there on early K2s but not on more recent versions. Can I just
connect together the pads marked X and 8T (on page 9 of the K60XV
Well, I've been doing lots of measurements and inspections and I'm still not
sure what is the matter.
As suggested I rechecked the DC voltages on Q6 and got 1.03 V on the base and
0.25 V on the emitter. The difference is 0.79 V - high, but plausible.
The emitter resistor R50 measures 1.4
of Q6 might be a bit weak...but it
doesn't quite feel like what would drop the power by 10 dB. The bias is about
right...around 1.05V.
Thanks 73,
Steve VE3SMA
- Original Message -
From: Don Wilhelm w3...@embarqmail.com
To: Steve Kavanagh skavanag...@yahoo.ca; Elecraft@mailman.qth.net
As I proceed with checking the new-to-me (S/N 5133, bare-bones, no options) K2
out, I'm finding that the maximum transmit power output drops markedly as the
frequency goes up. If I set the power to maximum, I can get the following
approximate powers (on CW):
80m: 15 W
40m: 15 W
30m: 15 W
I just acquired a second hand K2 (my second one) and upon going thru the
operation in detail I noticed that it was somewhat off frequency. WWV at 10
MHz is received best (on USB using the CW filter - there is no SSB board) at
10,000.96 MHz and adjusting C22 has no discernible effect on the
Thanks for setting me straight, Don and Mike. I think have the hang of it
now...calibration is much better now - though I still may want to refine it a
bit. Though, I didn't seem to be able to make the N6KR method work on WWV at
20 MHz - couldn't get a frequency match. But it's ok at 15 MHz.
I noticed this past weekend that my K2's transverter output level was lower
than the nominal 1 mW it was set to when operating from the car battery with
the ignition off. I confirmed this behaviour today, with about a 12.2 V power
supply voltage to the K2. The power control of the K60XV
with that lower level.
The reason for changing the TRN menus is to keep from overdriving the
transverters when operating from a higher voltage power source.
73,
Don W3FPR
On 6/18/2014 10:03 AM, Steve Kavanagh wrote:
I noticed this past weekend that my K2's transverter output level was lower
than
Lloyd
One option for the K2/transverter hot switching problem on CW is to build a
sequencer which breaks the TX IF line, like this one:
http://www.qsl.net/ve3sma/3OutputSequencerForK2.pdf
This only works, however, if you are running very low IF power from the K60XV
(or at least run the 10W
While it's convenient to have all the settings specified by N0SS (SK), keep in
mind that there are a variety of other audio spectrum analyzer programs
available which are suitable for K2 CAL FIL alignment. For example, I used
Spectran (written by I2PHD) under Windows 7 the other day to
I just received a KAF2 audio filter kit for my K2 and I am considering a few
mods when I build it, to increase the bandwidth somewhat, and to increase the
gain. My use of the K2 is mostly for VHF weak signal work with transverters,
often outdoors with lots of background noise (surf, crickets
Thanks for your comments, Ron. My fuseholder isn't gradually meltingit's a
pretty robust one and teh spring effect is fine, but small contact area and
dissimilar metals appears to be the issue. It seems like the automotive blade
fuses are the wave of the future in ham radio !
73,
Steve
Thanks for your comments, Sverre and Mike. Yes, I believe I have had
RF-induced odd keying problems (with a transverter/amp on 144 MHz at about
100-300 W out, the key being around 5m from the antenna, but not in the main
beam). They seemed to respond to moving cables around, putting ferrite
It looks like one of the causes of my chirp on 222 MHz with the K2/XV222 combo
was
an unreliable fuseholder (an in-line type for an AGC/3AG/1-1/4x1/4 inch fuse).
I wonder
if automotive blade type fuses/holders might be more reliable as far as contact
resistance
goes. Does anyone have any
I'm replacing a dead diode in my paddle/key combiner box. Does it matter at
all what types of diodes I use ? I am thinking maybe I should use something
less prone to RF pickup (say 1N4001 or similar) rather than the HP 5082-2835's
(small signal schottkys) I had there originally.
73,
Steve
I got a report of chirp when running CW on 222 MHz during the VHF contest this
past weekend.
This has been confirmed by a few others since the contest. It's quite possible
that the various voltage
drops from the Rover vehicle battery to the XV222 were not leaving enough
headroom for the 78L09
To: Steve Kavanagh skavanag...@yahoo.ca
Cc: elecraft@mailman.qth.net elecraft@mailman.qth.net
Sent: Tuesday, June 11, 2013 7:14:40 PM
Subject: Re: [Elecraft] Chirp with K2/XV222
Steve,
I would think your assumptions for the cause may be correct.
BUT -- rather than changing the XV222, I would
My apologies regarding the link...as W1RT correctly figured out there should be
an L at the end of it:
www.qsl.net/ve3sma/downloads.html
I had seen Don's circuit and decided to go a different route...not having to
dig into the K2 was a plus for me (and I had a good supply of the Omron G5Y
--- On Tue, 11/8/11, Don Wilhelm w3...@embarqmail.com wrote:
From: Don Wilhelm w3...@embarqmail.com
Subject: Re: [Elecraft] [K2] Solutions for K2 Transverter Quirks
To: Steve Kavanagh skavanag...@yahoo.ca
Cc: elecraft@mailman.qth.net
Received: Tuesday, November 8, 2011, 9:14 AM
Steve
--- On Tue, 11/8/11, Don Wilhelm wrote:
Considering the source of your VHF energy, I would think that a low pass
filter on the RX jack (as well as one just in case on the TX jack)
would take care of that problem.
Actually, Don, it's the other way round. The offending detector is on the
The K2 makes quite a nice IF rig for VHF transverters, but it has a few quirks,
like most rigs. I've put my solutions to two issues up at
www.qsl.net/ve3sma/downloads.htm .
First is a sequencer which switches the RF to the transverter to prevent it
from transmitting while its internal
We were thinking along the lines of 200-500 mW for the micro
transverter, if it's even possible. The regular transverter option
could be as high as 5 W. We'll see.
Wayne
N6KR
Now that sounds interesting. I run a bunch of microwave transverters from a 2m
IF at 50-100 mW and have found no
Recently I noticed some odd behaviour of the K2/K60XV driving a DEMI 2m
transverter and an amp. Switching on and off my rotor control box or the
AC-powered fan for the amp caused the K2 to do the following: (1)
receiver muted for about 1 second, (2) S-meter read S9+40 dB for the same
time and
Stu
A couple of thoughts.
You didn't mention if the oscillation was occurring with the amp driving an
antenna or a dummy load. The Elecraft transverters have lots of nice features
but they are quite poorly shielded. If you were using an antenna you might be
getting an RF feedback loop
I was just pondering if I could use my K2 for transverter operation at 29.4
MHz, despite the specified upper frequency limit on 10m being 28.8 MHz. On my
unit, at least, the VCO still works. I can hear signals but it seems they are
probably a bit attenuated. Does anyone have real data on how
Frank:
I have done quite a bit of operating on 6m SSB with 10 watts and a dipole (and
in the past with 2 watts and a dipole). Unfortunately I haven't had a K3 to do
it with, but one the current versions is a K2 and homebrew transverter.
My dipole heights have ranged from 12 feet to 30 feet,
John:
The values I used are in the 1st link I sent, if you dig down far enough.
I put a 1k resistor in series with the base of Q1 in
the KSB2 and put 3.3k in parallel with R9. It's
pretty fiddly work on this compact board, but doable.
This is in the middle of the range for R9 suggested
Is there any way of making the ALC more aggressive on 40m SSB, without
affecting the other bands too much? I remember seeing a previous post
about this somewhere but haven't been able to find the details again.
Any suggestions?
73,
John
VK7JB
John:
You probably have the diagnosis exactly
Ken:
The excessive power could also be due to a problem some of us have had where
the KPA100 gain is high enough that the ALC circuits do not have enough range
to control the power on some bands (typically 80m and/or 40m). Only SSB is
affected, not CW.
See:
That filter has pretty much the same attenuation at 50 MHz as my homebrew one,
so yes, it should work fine. Mine has better match at 28 MHz, at the expense
of not as good match at lower frequencies. I ended up with the following,
after some tweaking
My filter is a two section low-pass
A couple of weeks ago I posted here regarding a problem whereby transmitting on
my 6m rig cause my XV222 (connected to K2/K60XV) to key up.
It appears that if any moderate amount of stray RF ends up on the tranmit IF
line (probably due to imperfect shielding of the transverter rear panel
I just tried another test, which I think tends to confirm my theory in some way
(or that something is amiss). When I apply my 0.5 mW 146 MHz test source to
the XVTR OUT jack, the DC voltage at the cathode of D3 in the K60XV (the
detector for VRFDET) increases from zero to about 0.1 volts. So
Terry:
I have seen much the same thing with a DEM transverter and my K2, and I agree
with your assessment. The IF circuitry in the DEM transverters does not seem
to be designed to give anything close to a 50 ohm input impedance, especially
when set for for very low input powers. It is quite
Thanks for taking the time to consider my problem, Don. Here's a few more
observations.
If the 8R line in the K2 goes low, it is because the K2 has
entered the transmit state.
You'd think so, but since the display does not show a frequency change between
the receive state and the
Don:
Thanks for the quick reply !
I'd reply off list with the nitty gritty details but I did have a request from
another interested ham to make the results public.
I have now put together a much more controlled test setup for the K2 that
doesn't involve high levels of RF all over the shack !
Does the K2 have a feature where a sufficiently high V RFDET voltage causes the
8R line to go low, thus switching the PIN (1N4007) diodes and protecting the
receiver from damage if high power is applied to the antenna socket while
receiving ?
If so this would explain the behaviour I have been
MHz from where the K2 is receiving ?
73,
Steve Kavanagh VE3SMA
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Post
I read on this forum that there is about 15
milliseconds delay between the transition of the 8R
line from receive to transmit (and hence of the key
out lines in the KPA100 and K60XV) and the beginning
of RF output. I have a couple of questions with
respect to this delay:
(1) Does this apply on
A local has a current-model Down East Microwave 2m
transverter for sale which I am considering for use
with my K2. From this forum and relay data sheets it
looks like the transverter will switch fast enough
that it can be used with the K60XV keying output
without a sequencer, with no hot
I am part way through the build of my K60XV and am
trying to sort out how to interface it to my various
existing homebrew and non-Elecraft transverters. A
couple of questions have arisen:
(1) I hope to use the transverter keyline output
(J2-pin 2 on the K60XV), but there is no connector (or
Bill:
It could be the problem I and some others had, where
there was a bit too much gain through the transmit
chain when the KPA-100 is installed for the ALC to
maintain control (in my case it was worst on 80m).
Here is a link to my problem solved post, which also
links to my original problem
--- Geoffrey Mackenzie-Kennedy
[EMAIL PROTECTED] wrote:
Have you any thoughts about what might be causing
Don's K2/100 to behave
when he switches the display from RF to ALC?
Yes, that is quite unexpected ! David, M0DHO, brought
this peculiarity to my attention and I noticed the
same
I think Don's observations sound like the problem I
and a few others have had. See, for example the
symptoms described here:
http://www.ac6rm.net/mailarchive/html/elecraft-list/2005-03/msg00676.html
http://www.ac6rm.net/mailarchive/html/elecraft-list/2005-12/msg00408.html
These two, at least,
A few recent units have shown problems that at least
sound similar to this one. See, for example:
http://www.ac6rm.net/mailarchive/html/elecraft-list/2005-03/msg00676.html
http://www.ac6rm.net/mailarchive/html/elecraft-list/2005-12/msg00408.html
These two, at least, were due to the KSB2 ALC
Raj:
I trust you didn't have the RIT on by mistake ? I
find I often leave the RIT on and forget about it with
the K2. The flashing indicator just doesn't seem to
be obvious enough to me to remind me to turn it off.
73,
Steve VE3SMA
__
Do You
I just purchased a used 1210 yesterday with the idea
to use it with my K2...I haven't tried it yet. Lee, I
should have it on the air for initial tests within a
few days and can report.
But I am confused about noise figure specs. The
manual (copyright 1997) I received with it specifies a
2 dB
Roy:
I assume you are probably making these
measurements/observations on CW, in which case I can't
add to what has already been suggested.
However, if you are testing in SSB mode, there is
another possibility. Some K2/100's have trouble
keeping the power down on SSB, especially on 80m. The
John:
I think I recall a post here where someone had blown
up an XV front end in a rover setup by transmitting on
an adjacent band (as I recall at the 100-200 W level).
There's just one tuned circuit in front of the preamp
FET in the XV's, so bandpass filters wouldn't be a bad
idea.
By the way,
Juha:
It sounds something like the problem I had (and have
still not completely fixed as it got a bit worse when
I installed the new resistors per Builder Alert 22A).
See
http://www.ac6rm.net/mailarchive/html/elecraft-list/2005-12/msg00408.html
M0DHO had the same problemsee
Regarding the thread I started a couple of weeks
ago...
I found some strong intermod products from AM (medium
wave) broadcast stations on and around 80m when using
a large inverted L and low-pass L-network antenna
tuner. The strongest was the combination of 2 x 1310
kHz + 580 kHz, two local 50
Thanks to all who shared their experience and
suggestions. Some interesting approaches indeed.
I decided to try the spring-loaded solder sucker
method, since one was available. It worked well enough
(in conjunction with a bit of lead prodding) on all
the ungrounded pins, but I couldn't get the
OK, while everyone seems to be on the subject of
stupidity...I just found I installed two of Elecraft's
ubiquitous latching relays incorrectly (after several
checks to make sure it was done right !).
Has anyone ever successfully unsoldered one without
serious damage to either the relay or the
As far as I can see from the manual, the KPA100 T-R
switch is bypassed in QRP mode. As the intermods
occur in both QRP and high power modes the KPA100 T-R
switch can not be the only culprit. With more careful
observations I see that there are fairly small changes
in the S-meter readings on the
Thanks to advice from M0DHO, LA3ZA and Gary Surrency
at Elecraft the problem described in
http://www.ac6rm.net/mailarchive/html/elecraft-list/2005-12/msg00408.html
is now solved, or nearly so. I still see a big jump
in SSB power between 10 and 11 watt settings, but the
power output is always
I just had my first opportunity to use the K2/100 on a
fairly large antenna for 80m (inverted L with total
wire length around 150 ft., through a low-pass type of
antenna tuner). I noticed a few fairly strong
intermodulation products from AM (medium wave)
broadcast stations on and around 80m.
When I try to run SSB on 80, 40 or 30m (the latter for
purposes of completeness only !) at power levels above
10 W but below 100 W I find the power control is not
working properly. There is no problem on CW, or above
14 MHz, or below 10 watts. S/N is 4509.
Here are some typical measured numbers
This summer I experienced an RFI problem with my
Astron RS-7A which was completely cured by connecting
the negative output terminal to the ground stud on the
back of the supply. Never had to do that before in
perhaps 15 years of owning the power supply - didn't
even know the supply was floating
I purchased a recently built K2/100 this summer and am
gradually working my way through careful evaluations.
Today I checked the key-down current and found some
variations that look rather like those mentioned in
Builder Alert #22a. Here are the current readings in
amps, at 75 and 100 watts
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