I've discovered that my VPWR voltage is high (4.90 V). I don't see
anything wrong with the RF Detector circuit. The signal on D9 is only 84
mV when measured with the RF Probe. So I pressed forward with signal
tracing. It appears I have an RF signal at the Transmit Mixer (0.274 V)
and Buffer
Murray,
Not only logical, but the only way to approach Transmit problems.
When you get to jumper W6, know that you can and should adjust the
bandpass filters for maximum RF voltage there.
On a new build, be aware that the most common problems are soldering,
misplaced or incorrect components
Don,
A logical suggestion. I already have made the RF Probe and it's ready to
use. I was hoping the cause of no power might be something simpler. I
will start troubleshooting in my next work session.
Murray VA1CQ
On 6/26/2021 5:34 PM, Don Wilhelm wrote:
Murray,
I suggest that you build
Murray,
I suggest that you build the RF Probe that was included with the K2
kit. The schematic is shown on page 9 of Appendix E along with the
assembly instructions.
After that, start on Appendix E page 12 - Preparation for Transmitter
Signal Tracing and follow the steps shown there.
73,
I am just completing the build of K2 Serial No. 6397. Everything was
going perfectly with all receiver tests and adjustments. Everything is
in spec.
Then I started the transmitter tests. I set the output power control for
2.0 watts. Beginning on 40 metres, I am supposed to be able to adjust
Hi Don,
many thanks for all kind help and ideas.
I will try to call him in order to explain all of these steps to be checked.
Most important is to double check what the real power is from his K2 as
I do not know if he measured the output power correctly with his external
equipment.
Again Don
Petr,
The specification for the K2 is for 10 watts or greater. Most will go
to 12 watts on 40 and 30 meters with an adequate power supply voltage
while few can achieve 15 watts on all bands.
There is nothing specific to the KPA100 option that would cause low
power output from the base K2.
Hi folks,
my colleque got as birthday gift from family the K2. All seems ok, receiver
works excellent.
The only issue he found is the low power output thru all bands. He can not
get 15W but something
below 10W... He mentioned in last email that preview owner had installed
KPA100 option which
has
Brian,
Do things settle down if you drive a dummy load instead of the antenna?
If so, that would nail it as an RF Feedback. If that is the case, use a
good quality common mode choke at the junction of the coax with the
ladderline. See K9YC's RFI information at
Brian,
The Elecraft K series requires a different way of setting power out on digital.
You increase the audio drive from the SignaLink until the "ALC" meter is
showing 4 to 5 bars and then adjust the power control to set the required power
out, do not use the audio level to adjust the power.
Brian,
Too early in the morning with me, I just noticed the fact you have a K2 not a
K3 or KX3.
In that case the ALC meter is different, but perhaps you may find something
that is helpful on the late G4ILO's site:
http://www.g4ilo.com/k2psk31.html
73
David Anderson GM4JJJ
> On 25 Oct
Don,
Yes, things settle down with a dummy load, so it looks like I'm dealing with
RF feedback.
Per the original post, I'm using an Elecraft BL2 balun at the
coax/ladderline junction. Shouldn't this act as the common mode choke that
you suggest or are you suggesting to place a common mode choke
My take on this is baluns are baluns and common mode chokes are common
mode chokes. In many cases baluns do not provide adequate common mode
choking requirements. Thus both may be needed. Usually, the balun is
located physically at the load and the common mode choke is located at
the source.
Yep, almost. The word "balun" is a portmanteau of "balanced" and
"unbalanced." They are transformers or auto-transformers and their job
is to keep a balanced feed to the antenna balanced when transitioning to
unbalanced coax. Since they're transformers, they can also transform
the
Brian,
The Elecraft BL2 is a good common mode choke. It is rated at 250 watts
into a *matched* load.
Your load certainly is not matched, and I do not know how to de-rate the
power for any given load.
Check to see if the balun core heats - if so, you could be operating the
BL2 outside its
Yes. And even more important -- the word "balun" is used to describe so
many (at least) ten different very kinds of components that the word
itself should be banned from our language. ONE of those components is a
common mode choke. Another is an array of common mode chokes. Another is
a
I'm having an issue with unstable power output using digital modes on 40m
above about 20 watts. All other bands seem to be ok.
My antenna setup is as follows: a loop consisting of about 245 feet of wire,
feed line consists of about 21 feet of 450 ohm ladderline to an Elecraft BL2
balun, then
I recently acquired a very clean K2/100 with external KAT100 ATU. I
have a K3/100 and its power output agrees closely with the readings of
both Bird and Elecraft W2 watt meters. According to these watt meters
the K2, set to full power of 110W, puts out about 80 - 85 W into a dummy
load (SWR
Dave,
It may be that the wattmeter in the KPA100 needs calibration - and is
the most likely reason.
Dig out the KPA100 manual and look at page 48.
Do the SWR Bridge Null Adjustment first.
Then do the Power Calibration.
There may be some variability in the calibration from band to band
Hello
My K2/100 just recently started going to 100 watts output
as soon as I set the output to 11 watts or greater.
I disconnected the amp, and am back to the qrp version and
everything works fine. So I asume the problem is with the
amp. Am I correct?
Thanks
Scott N5SM
Scott,
Yes, the problem is with the KPA100. The most likely thing is that
diodes D16 and D17 are damaged which results in the KPA100 not being
able to tell the K2 that power output is being developed, so the K2 just
increases the power to the max in an effort to obtain a power output
Don,
I can't find any problems with the KAT2 cables. I removed the KAT2 from
the rig by disconnecting the coax at P6 and the 10-pin connector. Using the
BNC connector marked ANTENNA, I've connected my dummy load.I set the power
level at 5 watts and pressed TUNE and only see an output of 0.2
I just finished installing the KDPS2 boards and they check out OK. I also have
the KAT2 installed and it was working.
I was going to operate today for the first time but when pressing TUNE, I'm
not getting any power out. I have an external watt meter too. When I press
TUNE, I see Atu on
Are you by any chance in TEST mode??
If so the c and the underline on the display will be blinking and you'll
get no power output.
Hold the MODE button to return to normal operation.
Ron AC7AC
-Original Message-
I just finished installing the KDPS2 boards and they check out OK. I
Gary,
This problem has nothing to do directly with the installation of the KDSP2.
Think of whatever else you may have accidently touched - the KAT2 cables are
a relevant example.
Remove the KAT2 and feed the K2 directly into a 50 ohm dummy load - when you
press TUNE you should see the output
Hi Don,
I do not have any power meter which can measure any RF power output less
than 1 watt. Could you please advise the minimum output power level of K2
with the power knot fully CCW?
BTW, under the SEC menu of K2, the transverter output (without the
installation of KV60) can be lowered
Hi
I have owned K2 #3914 for a few years now, but just recently
it has developed a rather strange fault.
On all bands, whatever the requested power level using the
front Panel power knob, the bargraph display and power
indication from the Pout display from the onboard atu
indicate no
Bob,
I would have to have a lot more data for a more definite analysis, but one
thing that can cause 'funny' power readings is the diodes in the ATU
wattmeter. They are sitting right out there on the antenna line where they
can be easily subjected to static discharges. You may want to
Hello all,
I completed the transmitter alignment on K2 #4429 recently. In checking the
power output on all the bands I found that I can indeed get just over 10w on
10m at 28.2 MHz (the frequency used to peak the bandpass filters) as long as I
am using a power supply. Using a battery, I had
Ben,
The place where one aligns the bandpass filter on 10 meters must depend on
the 10 meter operating that is anticipated. If the interest is mainly CW,
the bandpass filter would be peaked at 28.2 MHz as stated in the manual --
OTOH, if more phone operation (or CW higher in the band) is more
@mailman.qth.netmailto:elecraft@mailman.qth.net
Sent: Friday, July 16, 2004 11:07 AM
Subject: [Elecraft] K2 #4130 power output result
Now, after a little technical briefing by Tom N0SS and Gary AB7MY
(thanks),
There are my K2 power output results using the DL1 dummy load when
applying
Good morning Elecrafters!
My K2 power output problem solved, first QSO done. Everything seems to be
OK now.
Yesterday my friend Sami, OH4KLU, came over and we looked together into
K2 problem. There was no indication of TX nowhere. 8R voltage went down
to 0.6 V, not below 0.3 V. We started to
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