OK,
I confess that after building control and receiver circuits [carefully]
with no problems, I wanted to believe the rig was 100% after initial
transmitter alignment. I put the rig on the air and made contact immediately.
THEN: a friend loaned me his OHR WM-1 wattmeter so I could actually
measure the output. It was all over the map, but always low and not very
repeatable.
I checked the soldering.
I resoldered everything that looked even a little suspect.
I measured the resistance of each of the toroids and transformers.
I measured dc voltages.
I monotored the ALC circuit.
I measured rf voltages in the transmitter with the provided probe kit.
Everything seemed ok except the transmitter was low on drive and the power
supply current was high.
Wait, I see a patern! Time to check my dummy load.
[I have been using 2w dummy loads for my other qrp rigs. For this job the only
thing I have >2w is a Heath Cantenna <2Kw>]
The Cantenna is open! Dummy load is 100Kohm. Not good - but happy dance, the
radio is fine [I was very careful with the finals! Very short test times and
reasonable current limits.
I check the radio with my qrpp dummy load [1 watt] and all bands put out
the asked for [low] power.
I repaired the Cantenna and touched up the transmitter alignment. Power is
predictable and controlled on all bands.
Time to open the SSB kit.
The lesson once again is do not assume things - I had not used the dummy load
since going qrp 10 years ago.
Wayne
K9NE
K2 S/N 04858
_______________________________________________
Elecraft mailing list
Post to: Elecraft@mailman.qth.net
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
