Re: [Elecraft] PA failure

[Arie Lukkassen]

Chris,
Please explain about why those transistors with the same number did not work. 
Is the spec the same?
Is the pin layout different?
I'm confused to read this.
Thanks
Arie
JE1RYS

- Original Message 
From: Hans-Christoph Scheiblberger [EMAIL PROTECTED]
To: elecraft@mailman.qth.net
Sent: Wednesday, December 20, 2006 5:30:27 PM
Subject: [Elecraft] PA failure


Dear Elecrafters,

After weeks of repair work we finally found out what was wrong with the 10 Watt 
pa of my K2.Thanks to all who helped us, epecially Don Williams and Gary from 
Elecraft.
The former owner of my K2 also helped us a lot.He said,that we needed the 
original Elecraft PA transistors and it might not work with transistors bought 
in the EU. We found out that he was right-the rig did not work with transistors 
from Germany, produced by the same company and also with the same number on 
it.Even the size was different.
This was something very new to me. I always thought that transistors with the 
same number were equal.
It seems that you really need original parts.

73,Chris-OE5CSP
-- 
Der GMX SmartSurfer hilft bis zu 70% Ihrer Onlinekosten zu sparen! 
Ideal für Modem und ISDN: http://www.gmx.net/de/go/smartsurfer
___
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

__
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 
___
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

RE: [Elecraft] PA failure

[Don Wilhelm]

Chris,

Check T4 very carefully - does it have the correct number of turns?  Is the
correct winding inserted into the correct holes?  Are the links present and
soldered into the correct holes?

Your bias voltage is a bit high - check to be certain Q11 and Q13 have the
expected DC voltages (see the DC Voltage chart in Appendix E of the manual).

Examine all components in the base of Q7 and Q8 (see the schematic to
identify all the components) and verify that they are correct.

73,
Don W3FPR

 -Original Message-


 Dear group!

 We have a serious problem with our 10watt PA of my K2.2 weeks ago
 the 10w PA suddenly didn´t work any more.A friend helped me to
 fix the problem(we replaced the PA transistors 3 times), but now
 we need your help.The PA needs far too much current and the
 maximum power output on all bands is 2 watt.Everything seems to
 be okay, but the current of the bias of Q7/Q8 is 0.656V instead of 0.600.

 The  PA transistors and the diodes of the low pass filter are
 okay too.Can you please help?

 vy73, Chris-OE5CSP


___
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