40m transmitter test FAILS

[mikekopacki]

Well, just go through the final assembly tests and started the alignment testing.  I was feeling good when all the resistance checks were good.  But then I did the 40m transmitter test, per the book.

When I set the power out to 2.0 watts, then hit the TUNE button, I got wildly varying output readings.  The output varied constantly and quickly from about 2 - 8 watts.  This was at a supply voltage of 14 volts.  At 12v, it varied from 2-6 watts.  When repeating the test, I have seen readings varying from 13-18 watts!

And again, this is varying constantly and quickly, and it never stabilizes.

I talked to Elecraft support last night and he suggested that I check the components in the RF output detector stage.  I did that and did not find anything.  The components were the right ones, oriented correctly, and I reheated all the solder joints.  I did not take any of the resistors out of circuit to measure them.

I sent Elecraft an email late last night on the results of what they suggested and am waiting for a reply, but thought in the meantime I would see if any of you have experienced the same thing.  I have gotten good feedback from this group already!

I also found that if I set the output power to a lower level, like .5w, the test was fine.  I could gradually increase this setting, with good test results, until I get to about 1.2 - 1.4 watts.  Somewhere in that range I start to get the wild readings.

So thanks again,
Mike, NJ2OM
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Ron D'Eau Claire-2]

Mike, are you talking about a K2? If so, check R66 and R69.

R66, 2.7k (red-vio-red) is closest to connecter P3 and the edge of the board
while R69, 100k (brn-blk-yel) is farthest from the edge of the board.

If they are reversed, the RF detector will work, sort of, but the readings
well be very unstable.

Ron AC7AC

-----Original Message-----
Well, just go through the final assembly tests and started the alignment
testing.  I was feeling good when all the resistance checks were good.  But
then I did the 40m transmitter test, per the book.

When I set the power out to 2.0 watts, then hit the TUNE button, I got
wildly varying output readings.  The output varied constantly and quickly
from about 2 - 8 watts.  This was at a supply voltage of 14 volts.  At 12v,
it varied from 2-6 watts.  When repeating the test, I have seen readings
varying from 13-18 watts!

And again, this is varying constantly and quickly, and it never stabilizes.

I talked to Elecraft support last night and he suggested that I check the
components in the RF output detector stage.  I did that and did not find
anything.  The components were the right ones, oriented correctly, and I
reheated all the solder joints.  I did not take any of the resistors out of
circuit to measure them.

I sent Elecraft an email late last night on the results of what they
suggested and am waiting for a reply, but thought in the meantime I would
see if any of you have experienced the same thing.  I have gotten good
feedback from this group already!

I also found that if I set the output power to a lower level, like .5w, the
test was fine.  I could gradually increase this setting, with good test
results, until I get to about 1.2 - 1.4 watts.  Somewhere in that range I
start to get the wild readings.

So thanks again,
Mike, NJ2OM


_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com