<VV> AM/FM Radio Schematics for Corvairs

[Tony Underwood]

At 06:10 PM 4/24/2010, Sethracer at aol.com wrote:
>
>
>In a message dated 4/24/2010 1:23:46 P.M. Pacific Daylight Time,
>eprosise at hotmail.com writes:
>
>Seth -  Sounds Ok - I guess I have not seen a complete FM radio in my
>possession in  some time.




I got lucky...


Back When, I went to work for an outfit that did Delco warranty 
work.   The shop had factory manuals going back to the mid-'60s.   I 
did warranty (and carry-in) work on auto radios for many years, then 
went back into photography... then back into automotive electronics 
AGAIN, this time for another shop (part of a three-state-wide chain) 
doing warranty work on the Big Three's 1990s car audio stuff.    I 
still kept in touch with the guys from the first shop however, and 
recently when they relocated to a bigger place and stopped doing auto 
stereo work, the service manager gave me their 1960s factory Delco 
audio service manuals.    The 2nd shop later closed down and I went 
into commercial electronics (since consumer electronics work has 
pretty much dried up these days with the throw-away concept hard at 
work for most automotive electronics).    This actually tends to 
leave a bit of a demand for repairs on old car radios that not many 
people can do anymore, mostly because of parts shortages and service 
info being hard to find.

:)

The Howard W Sams publications are pretty good and quite handy, but 
the factory Delco manuals are WAY overkill in their detail and parts 
number listings, down to the numbers for the last screw and 
washer.    They also include detailed/complete alignment instructions 
for everything imaginable.


It's pretty good stuff...


The other shop also gave me all their oddball old Delco parts, what 
they had left in stock anyway... including the replacement silicon 
transistor kits to upgrade radios with original germanium "DS" number 
semiconductors which simply aren't available anymore.  The kits 
consist of a silicon transistor, a resistor, a small ceramic 
capacitor, and a small schematic showing where the resistor and cap 
go to fool the radio into thinking it has a germanium transistor 
there.   Actually, on a lark, after looking closely at the radio 
schematic and noting how the germanium transistors are biased (simple 
dropping resistor from the source voltage to the base of the 
transistor), I simply swapped out a silicon PNP high-freq transistor 
for a germanium DS-25 in one Delco radio and it worked perfectly 
without the resistor and capacitor mod.   Since then, in those cranky 
IF circuits, I've just swapped out the defective transistors and not 
used the cap and resistor, radio always worked perfectly if not a bit 
better.

...still like to keep a hand in, although time to do this sort of 
thing often tends to be short.



tony..