It seems you have a soldered joint that touch to ground between T2 and
the PA Q7,Q8 or between Q11 or Q13. Check with a magnifier glass around
there. Sometimes you found a soldered joint touch (microscopic lead) to
another part, and that's it.... grounded !!!
Look near all places in this area that parts that should be to ground,
if you do not put too much solder and grounded another part that must
no be to ground.
Seems to me that a defective part should not do what you say, like a
reset when you set higher power. So it must be a bad solder.... I hope
for you.
Le 04-07-10, à 11:26, Nicolas Pike a écrit :
Hi,
B C E
Q6 1.04 13.5 .28
Q7 0 13.5 0
Q8 0 13.5 0
This is at .2 of a watt, any higher and the radio resets...
Thanks!!!!
Regards
Nicolas
Previous email for reference
----- Original Message -----
From: Nicolas Pike
To: elecraft@mailman.qth.net
Sent: Friday, July 09, 2004 6:40 PM
Subject: [Elecraft] RE: K2 4039, Failing transmitter tests
Hi,
I have steadily and carefully built my K2 and it has passed all the
tests so
far with flying colours, including 40m RX. Now I have just completed
the
transmitter stages, and attempted the first tx test... Ah problems.
Well
things have gone well so far!! Even a bottle of Hoegaarden did not
help...
This is what happens.
1.40m rx working fine.
2. Connect dummy load etc
3. Set for 2.0 output, tune to 7100
4. Press and hold tune.
A bleep in the headphones, the output limiter on the PSU flicks in
cutting
the power briefly and Elecraft displays on the K2. (I have tried
another PSU
(3amp) but the same result) If the power is turned down to .2 or so
it will
stay in tune mode
Upon checking the antenna connection, there appears to be a short
between
earth and the centre of the BNC.. (Using a DVM) This cannot be correct?
I have tried another PSU (3amp) but the same result.
Perhaps you could confirm if an indicated short across the BNC, is
incorrect, and any suggestions of where to look first would be very
helpful.
Thanks!!!!!
Regards
Nicolas
www.m1hog.com
-----Original Message-----
From: JEAN-FRANCOIS MENARD [mailto:[EMAIL PROTECTED]
Sent: 10 July 2004 15:34
To: [EMAIL PROTECTED]
Subject: Re: [Elecraft] RE: K2 4039,
What is the vDC you get on C,B and E on Q6, Q7 and Q8 when TX (hold
tune at 2W to check) ?
Le 04-07-10, à 10:26, Nicolas Pike a écrit :
Hi,
Thanks everyone for the suggestions. I now have some more information
to go
on!
Q7 Collector 3k OK!
Q6 Base 118Ohm OK!
Q7 Base SHORT Not OK!!!
I have checked the diodes, toroids T1 - T4, and carefully looked over
the
board for shorts. I have referred to the circuit diagram but I do not
really
know now to determine if the PA Bias section is grounding it, or if
the PA
section is grounding itself, or some other section is grounding them!!
(Although don't "think" much else can?)
Wondered if you had any suggestions?
Thanks
Nicolas
www.m1hog.com
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Checked by AVG anti-virus system (http://www.grisoft.com).
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===============================================
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[EMAIL PROTECTED]
Club d'Astronomie Amateur de Sherbrooke
Club Radio Amateur de l'Estrie
Mon site web personnel : http://homepage.mac.com/jfmenard
===============================================
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Subscriber Info (Addr. Change, sub, unsub etc.):
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