Possible to convert 42MC-50MC FM?

[DavGoodlin]

Does that mean these had both old and new FM bands? I had the StrombergCarlson for 32 years. I had it working then and it did get a few FM stations on the 200-300 band as I recall. I left the tuner at 102.5 FM as photo shows. BTW, I had an early mobile receiver that did receive a nearby TV's leaky sound carrier on 41.25 MC.

Thanks!
Dave 63

[sean]

Originally Posted by DavGoodlin

Does that mean these had both old and new FM bands?

It appears so. The first one should tune 88-108Mc on the 201-299 band and 42-50Mc on the 21-99 band (42.1 to 49.9Mc). The Stromberg Carlson radio would tune 88-108Mc on the 200-300 band and 42-50Mc on the 20-100 band (I would assume 42.0 to 51.0Mc).

BTW, the first photo is also a Stromberg Carlson:

http://www.radioatticarchives.com/radio.htm?radio=3198

[Jeffhs]

Originally Posted by sean

It appears so. The first one should tune 88-108Mc on the 201-299 band and 42-50Mc on the 21-99 band (42.1 to 49.9Mc). The Stromberg Carlson radio would tune 88-108Mc on the 200-300 band and 42-50Mc on the 20-100 band (I would assume 42.0 to 51.0Mc).

BTW, the first photo is also a Stromberg Carlson:

http://www.radioatticarchives.com/radio.htm?radio=3198

Some older (late '40s) Zenith radios also tuned AM and both FM bands, although the old FM scale on these sets was actually calibrated in MHz (mc) rather than channel numbers on that range. The radios I'm thinking of are the old Zeniths with the arc-shaped tuning dials and the ones with round dials and a "Tone Register" tone control system. I am guessing the latter were made in the late '40s as well, owing to the presence of the old 40-MHz FM band which was eliminated from all Zenith, et al. FM radios after all FM broadcasting transitioned to 88-108 MHz by 1949 or thereabouts.

There may be next to nothing to hear on the old 42-50 Mc. band today, although I suppose one could overhear old cordless telephones which operated on the old 46-49 MHz range if such are still in existence nowadays, which I doubt -- all current cordless telephones now operate in the GHz [gigahertz] range. Most of the old 46-49MHz cordless phones have probably been scrapped, due to being forced into obsolescence by the new 5.8 GHz phones now in use.

[cbenham]

Originally Posted by Jeffhs

There may be next to nothing to hear on the old 42-50 Mc. band today, although I suppose one could overhear old cordless telephones which operated on the old 46-49 MHz range if such are still in existence nowadays, which I doubt -- all current cordless telephones now operate in the GHz [gigahertz] range. Most of the old 46-49MHz cordless phones have probably been scrapped, due to being forced into obsolescence by the new 5.8 GHz phones now in use.

You can buy "win" a 'Sentry' HO 900 FM wireless headset system on eBay for ~$20 that transmits in the 42 to 50 MHZ band, crystal controlled and sounds very good when playing a cd through it.

It works great through my Philco 42-395 console.

Cliff

[vintagecollect]

hello benham,

It is possible, I built this rather quickly using fine magnet wire on thin masking tape forms. Made quickly, works but is simple and somewhat fragile. here's a photo, second photo is of my android phone showing station being picked up w/ signal meter showing strong signal. Being a totally passive system, probaly only works w/ strong signals, works well when does.

I'm going to try and make different coils using thicker magnet wire, may work better since thicker? I'm going to get some fm boosters used for car and put on front end to boost weaker signals to compensate for passive system.

The trimmer caps I used are 9 to 180pf, wide range, these are surplus and I can get quickly if someone wants to try this along w/ 1N34 diode.

Please show us pics of your 42 please Benham!