Quote:
Originally Posted by Telecolor 3007
Well, I got me an nice East-German (G.D.R.) made tube radio. The bad thing: printed curcuit boards. On A.F. no big problem, but on audio, where tubes (valves) are generating heat, the board startes to go nasty in time.
Did U.S.A. or West-German made radios hade this problem?
Anyway, in the future, I will not buy anything with tubes and printed circuits..
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It depends on the actual printed circuit. My understanding is that some traces were added to the substrate while others used a bonded copper layer that was etched. The additive boards were crap.
RCA was big with printed circuits early on and they were always excellent. The biggest problem with RCA was that the solder crystalized on high heat components like resistors and tube sockets over the years. Trying to resolder them was problematic. Back in the late 70s when RCA tube TVs were still plenty I used to invert the chassis and scrape down the tube sockets with a jeweler's screwdriver, apply liquid flux and use a high wattage iron to get the solder to reflow. Once done, they were rock solid.
I remember working on a B&W console TV (thinking it was a mid 60s Philco) with printed circuits sometime in the mid 70s, and this board was so crappy that as soon as the soldering iron was applied, the foil would roll back to the next component. I ended up pretty much having to hand wire from point to point anywhere I needed to solder. Those were exceptions though. Thank God..
John