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38-690 audio problem
#8

After going through this set many times over, I have concluded that the interstage/output transformer is bad - the reason I have no tweeter signal.

I waited until I finished fixing the bad tweeter in the set, a burned up field coil, and was able to connect both speakers to come to that conclusion.

As an experiment I connected a generic output transformer across the primary of the interstage and connected the secondary to the tweeters, and guess what? I have sound coming from them.

So my options are to find another interstage from a donor chassis or add the output transformer under the chassis.

Does anyone have a parts donor?

The rest of the set has come together quite nicely, here is the IF response at minimum bandwidth and maximum:

[Image: http://www.myvintagetv.com/posts/38-690_IF2.jpg]

Chuck


Messages In This Thread
38-690 audio problem - by chucka - 08-05-2012, 12:57 PM
RE: 38-690 audio problem - by morzh - 08-05-2012, 02:22 PM
RE: 38-690 audio problem - by Ron Ramirez - 08-05-2012, 04:15 PM
RE: 38-690 audio problem - by chucka - 08-06-2012, 12:44 AM
RE: 38-690 audio problem - by codefox1 - 08-06-2012, 11:02 AM
RE: 38-690 audio problem - by Ron Ramirez - 08-06-2012, 03:51 PM
RE: 38-690 audio problem - by Ron Ramirez - 08-08-2012, 08:08 PM
RE: 38-690 audio problem - by chucka - 08-25-2012, 05:25 PM
RE: 38-690 audio problem - by chucka - 09-08-2012, 09:45 AM
RE: 38-690 audio problem - by jerryhawthorne - 09-08-2012, 11:09 PM
RE: 38-690 audio problem - by Ron Ramirez - 09-09-2012, 09:46 AM
RE: 38-690 audio problem - by jerryhawthorne - 09-09-2012, 01:34 PM
RE: 38-690 audio problem - by chucka - 09-10-2012, 10:17 PM
RE: 38-690 audio problem - by jerryhawthorne - 09-13-2012, 10:57 PM
RE: 38-690 audio problem - by chucka - 09-13-2012, 11:25 PM
RE: 38-690 audio problem - by jerryhawthorne - 09-13-2012, 11:41 PM
RE: 38-690 audio problem - by Ron Ramirez - 09-14-2012, 05:47 AM
RE: 38-690 audio problem - by chucka - 09-14-2012, 07:46 AM
RE: 38-690 audio problem - by chucka - 09-14-2012, 02:46 PM
RE: 38-690 audio problem - by Diverted - 03-17-2015, 11:32 AM



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