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!
:yes:

Coils in the FM bands are usually self-supporting made from bare 12 gauge copper wire, wound on a pencil or some other form 3/8 or 1/2" diameter, and then slipped off. The wire can come from stripped scraps of house wiring. They can be adjusted in frequency by compressing or expanding the turns slightly. The heavy wire helps make them frequency stable.

Hello Reece,

Sounds good to find some old house wire. It will need to be sprayed for insulation since both sets of coils are interwound onto each other. The diameter in projects states 7/8". The set benefits alignment with converter attached while adjusting trimmers also.

I tried converter on early post war Zenith I have w/ both old & new FM bands. Interestingly, the strong station came across as just strong modulation hum. I DID pick up a different station though, 104.9. station is very low and barely audible w/ volume turned all the way up. The Zenith was not aligned to be used w/ converter, just hooked tweak quicly up to see results. I really need to get those signal boosters to compensate for passive converter. Will post results later. I'm having a problem posting pics.

An ideal candidate for this converter may be a higher end large tube set, more sensitive ---should help in some way. The project states 12 wire used, I'm hoping someone here can build their version of converter w/ proper wire and post results since this is a simple tweak.

I don't see your pictures.

Its was kind of convoluted to accomplish but here is the page from Google Books with the FM Converter in pdf.

From the article it appears they are using 12 gauge wire with 18 gauge solid insulated wire interwound. It wouldn't matter that the 12 gauge is bare wire, stripped from a scrap of house wiring, since the 18 gauge hookup wire has its plastic insulation.

The easiest converter, WORKS good!!
 

The easiest converter works awesome on my philco prewar set. It helps if the set is sensitive w/ good volume since circuit is passive. MY westinhouse postwar early FM has a similair type circuit for it's FM part.Showing two specially wound air coils, along w/ 2 pairs of copper plates for tuning cap especially for FM use.

I've seen rare prewar to postwar converter selling for big bucks. I would rather make this --- and save sevral hundred dollars.