OK guys, now I need some guidance. I'm building K2 serial number 6625. I
am on page 48 on the manual, Setting the AGC Threshold. I have the RF GAIN
control fully clockwise. The highest voltage reading I can get on pin 5 of
U2 while adjusting R1 is 3.65V. The manual calls for 3.80V. All tests
Ken,
The problem is caused by the 8 volt regulator being on the low side of
its specification (the spec sheet says 7.5 to 8.5 volts is OK output for
the regulator - and the current batch of regulators at Aptos seem to be
on the low side (they were mostly on the high side a couple years ago -
Hmm, I went through that a couple weeks ago and I ended up needing to
replace the 8-volt regulator. Elecraft sent me a new one. Check the
output voltage on the 8-volt regulator (LM2930T-8) and see how close
it is to 8 volts.
I'll be interested to see what the more experienced builders have to
say
bill KE5KWE wrote:
This probably has been asked and answered before but I couldn't find it in
the archives. I Set the AGC Threshold and could only get 3.644 volts out of
R1 the potentiometer. Should I be concerned that I did not get 3.80 volts ?
I'd say it is a little on the low side, but
Hello All:
This probably has been asked and answered before but I couldn't find it in
the archives. I Set the AGC Threshold and could only get 3.644 volts out of
R1 the potentiometer. Should I be concerned that I did not get 3.80 volts ?
Thanks for the help.
Bill
KE5KWE
--
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On Nov 23, 2007, at 9:02 PM, Leigh L Klotz, Jr. wrote:
Circuit Specialists has meters and they throw in a free gift for
over $50. Or Fry's retail this weekend. BK is an OK economy
brand available at both places. The cheap analog meter might cause
you problems down the road with
Greetings Sarah, welcome to the hobby, and to a great radio. My AGC
measurement was down a bit, not quite as far as yours, but it has been
discussed here that there is some variation, and that it is not critical
at that point. I re-visited my a little later on in the build process,
and the
Sarah,
Congratulations on getting your license and venturing to build your K2.
The AGC Threshold high limit is directly proportional to the 8 volt
regulator actual output - if you follow the circuit you will discover
that that voltage is really the result of a 3 legged resistive voltage
On Nov 23, 2007, at 3:31 PM, Don Wilhelm wrote:
Sarah,
Congratulations on getting your license and venturing to build your
K2.
Thanks!
The AGC Threshold high limit is directly proportional to the 8 volt
regulator actual output - if you follow the circuit you will
discover that that
Well, I searched around a bit and found *another* cheap DMM, which
seels to be reading about 0.12 to 0.14 volts higher than the first
one. Now I don't know which one to believe! :-)
(Carry one watch, or three, but never two...)
Now I need to find my *other* other meter, the analog one I got when
Hi and welcome!
It doesn't happen too often, but have you checked the accuracy of your
cheap DMM? If you don't have anything to compare it with, you can get an
idea of its condition by measuring the voltage across a fresh alkaline
battery. It should read about 1.57 and 1.58 VDC.
Ron AC7AC
Thanks to everyone who replied! Wow, help sure comes in a hurry on
this list!
The general consensus appears to be that I'm ok for the time being
(yay!), so I'm going to go ahead and move on.
I did test with the internal voltmeter as well, and it reports 3.5V.
Special thanks to VE3TIX who
Hi,
I'm Sarah, AF6FH! I just got my license a couple weeks ago, and I'm
now assembling K2# 0622, which will be my first HF radio. I started
assembly on Wednesday night, and so far, everything's been going just
fine.
But...
I'm having a little issue with setting the AGC Threshold.
The
Welcome welcome Sarah!
Although you are starting at a time when signals are
low, stay on 40 meters at night and you cannot go
wrong. You have chosen the best possible place to
start your hobby, with the Elecraft group and there
are people here to help you with most anything outside
of typing your
On Nov 23, 2007 3:53 PM, Sarah K. [EMAIL PROTECTED] wrote:
I'm Sarah, AF6FH! I just got my license a couple weeks ago, and I'm
now assembling K2# 0622, which will be my first HF radio. I started
assembly on Wednesday night, and so far, everything's been going just
fine.
Congrats, and
Hi,
When I built my K2/100 the threshold adjustment didn't go right, I turn
trimmer R1 full CCW to get 3.74v on pin5 of U2 (full CW pin 5 goes to 2.6v).
This adjustment is supposed to swing U2 pin 5 fom from 4 to 8 v. I checked
diode polarity, resistor values, everything but never did find
by turning the
AGC on and off and adjusting for no change in the background noise.
Don Brown
KD5NDB
- Original Message -
From: Jim Stoneback [EMAIL PROTECTED]
To: elecraft@mailman.qth.net
Sent: Monday, October 08, 2007 1:53 PM
Subject: [Elecraft] K2 AGC Threshold Adjustment
Hi,
When
- Original Message -
From: Jim Stoneback [EMAIL PROTECTED]
To: elecraft@mailman.qth.net
Sent: Monday, October 08, 2007 11:53 AM
Subject: [Elecraft] K2 AGC Threshold Adjustment
Hi,
When I built my K2/100 the threshold adjustment didn't go right, I turn
trimmer R1 full CCW to get 3.74v on pin5
Mike,
Just to let you know that I have received a very positive response from
Elecraft about the K2's AGC Threshold setting problem..
Your DMM appears to be fine, and I hope that the info I sent you solves your
problem. Would appreciate hearing when you have time.
73,
GeoffGM4ESD
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