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Philco 42-350 FM
#5

There are a number of designs for FM down-converters that you can build. They take the modern FM signal and convert it to the old FM frequency. You connect the antenna to the converter and plug the converter into the antenna connection on the radio. I don't know of any that you can buy ready made.

One problem is that the old band was only 8 MHz wide instead of the 20MHz today, so the converters have to be wired to pull in only a portion of the modern band.

Try Googling "Pre-war FM band converter" or similar. I found quite a few hits when I did this. Somewhere I once found a small design that would be easy to built on a piece of perfboard, but I couldn't find it with the short amount of searching I did just now.

My 42-350 will actually pick up a few strong FM stations nearby, but not very well, probably because of oscillator harmonics.

I plug an FM tuner into my SSTRAN low power AM transmitter to rebroadcast on an AM frequency. Once I did that I gave up the idea of using the old FM band on any of my radios that have it.

Edited to add: Here is a page with links to several ways to build a down-converter for the pre-war FM band.

http://www.somerset.net/arm/fm_only_converters.html

Some of these are post-war designs from when radio shops were figuring out ways to help their customers adapt, and some are modern designs by old-radio enthusiasts. Near the bottom of the page is a "Simplified Modern Design" that I thought at one time of trying.

John Honeycutt


Messages In This Thread
Philco 42-350 FM - by shaler78 - 01-03-2015, 10:39 PM
RE: Philco 42-350 FM - by klondike98 - 01-04-2015, 07:58 AM
RE: Philco 42-350 FM - by Ron Ramirez - 01-04-2015, 09:54 AM
RE: Philco 42-350 FM - by shaler78 - 01-04-2015, 02:29 PM
RE: Philco 42-350 FM - by Raleigh - 02-14-2015, 04:39 PM



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