RadioBanter - AM to FM?

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- - AM to FM? (https://www.radiobanter.com/homebrew/84536-am-fm.html)

Hello, I have a 1969 Porsche that has an original, Blaupunkt, radio.
The AM works, but the FM does not. I was trying to find information on
a "FM to AM converter". If anyone has a schematic, or any advice at
all, I would GREATLY appreciate it. Thanks in advance!

In article . com,
says...
Hello, I have a 1969 Porsche that has an original, Blaupunkt, radio.
The AM works, but the FM does not. I was trying to find information on
a "FM to AM converter". If anyone has a schematic, or any advice at
all, I would GREATLY appreciate it. Thanks in advance!

I'd call these guys up (http://www.radiomanrepair.com/) and see if
they'll provide a quote for repair of the OEM radio. You'll have a
neat, operating vintage car radio, and you might even get the cash back
when you sell the car.

It isn't trivial to convert FM broadcast signals for reception in the AM
band. You pretty much need a back-to-back FM receiver and an AM
transmitter to do that, and the RF work associated with homebrewing a
converter would (honestly) place the task out of reach for anyone who
needs to ask how to do it. :-)

-- jm

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John Miles wrote:

In article . com,
says...

Hello, I have a 1969 Porsche that has an original, Blaupunkt, radio.
The AM works, but the FM does not. I was trying to find information on
a "FM to AM converter". If anyone has a schematic, or any advice at
all, I would GREATLY appreciate it. Thanks in advance!

I'd call these guys up (http://www.radiomanrepair.com/) and see if
they'll provide a quote for repair of the OEM radio. You'll have a
neat, operating vintage car radio, and you might even get the cash back
when you sell the car.

It isn't trivial to convert FM broadcast signals for reception in the AM
band. You pretty much need a back-to-back FM receiver and an AM
transmitter to do that, and the RF work associated with homebrewing a
converter would (honestly) place the task out of reach for anyone who
needs to ask how to do it. :-)

-- jm

They used to sell FM to AM converters for car radios. They 'worked' ok.
Watch ebay for Audiovox FM Converter. Here's one example.
http://cgi.ebay.com/ebaymotors/ws/eB...tem=4597467612

Regular old used ones generally sell for $15-20.

If it were me I'd get the original fixed, though.

-Bill

There are guys out there that will take your radio and stick new guts
in it. You end up with a radio that looks completely stock 1969
Porsche, but performs like a brand new Mark Levinson.

regards,
Bob

I TOTALLY AGREE!!! I will do NOTHING to deprive the originality of the
car. I was just curious as to my situation. Don't worry!

There is quite a large market for Porsche parts, even for older cars. There
is also quite a wide range of prices so it pays to look around.

I had the radio die in my '98 Boxster. It looked to be about $500 to repair
it, and a replacement was over $1200, over 700 for a rebuilt radio. Now, it
was a nice radio, but $1200!!

After much hand wringing and looking around I finally found a speed shop
halfway across the country that had a rebuilt radio for around $200. There
are literally hundreds of Porsche blogs and mod sites on the net; many of
these can provide leads. Don't forget the obvious Porsche suppliers and, of
course, eBay. Even if they don't directly have what you want, often they
can provide clues.

Back then those radios weren't that great, and a LOT of people yanked them
in favor of radios with cassette players or, later, CD's. Porsches tend to
be driven for a LONG time. So the odds of finding a replacement for a
decent price might be pretty good. Heck, I may have one of about that
vintage lying around here. Not much chance of ever finding it in this
shack, though!

As far as making a converter, I don't hold it to be quite as tough as some
of the other posters have indicated, but it could be a real barrier if you
aren't already a homebrewer. The fact that you are posting to a ham radio
newsgroup leads me to suspect you might not be a total innocent around a
soldering iron. There are a number of chips, NE612, 614, 615, that contain
a large fraction of an FM reciever. If you only want one station, it is
actually pretty simple. Building a high frequency VFO, though, is a bit of
a challenge. Modern synthesizer chips can greatly ease that, but they are
all little bitty surface mount parts, and you gotta program a computer chip
to drive them. Really not all that insurmountable, but it's not an
afternoon project, either!

Might not be such a bad plan to run down to Best Buy or whatever and get a
cheap replacement; pretty good radios are cheap enough that it could be
temporary. Then you have tunes while you are getting the real radio fixed.

...

wrote in message
oups.com...
I TOTALLY AGREE!!! I will do NOTHING to deprive the originality of the
car. I was just curious as to my situation. Don't worry!

soldering is my middle name.... but I want to keep the original
radio..............the most modifying I want to do would be to build
this converter

When you say "keeping it to one station"... do you mean the AM or the
FM?... I want to be able to change the AM, but if I have to keep the
Blaupunkt at one frequency to receive the signal from the converter, I
wouldn't mind at all.