E H Scott FM Converter

[Joseph W Strickland]

I see that there is an E H Scott FM Converter on eBay that uses acorn octal tubes. It allows conversion of modern band signals to the old band signals and vice versa. See:

http://www.ebay.com/itm/rare-e-h-scott-fm-radio-converter-adaptor-/...

This item is rather expensive, but for someone who really wants the capabilities it offers, it may be worth the expense.

Joe

[Norman S Braithwaite]

A few years ago some Scott FM converters sold for inexplicably high prices on eBay hence the sellers high initial listing price.  I wouldn't pay more than a couple hundred dollars at most.

Norman

[Joseph W Strickland]

Norman;

Good point. For an item that is seldom needed it is a very high price considering the unit only uses 3 tubes and the selector switch has to select which portion of the modern band to translate from to the low band. The chances are that it will not sell at the price listed. I expect we will see it disappear from the listings and re-appear at a lower price point.

I downloaded the schematic from our on-line database.

Joe

[Kent King]

Having operated a couple of these units, they tend to drift a bit, even with strong 717A tubes. I suppose capacitor leakage, resistor values, etc. impact stability too. They were produced for a limited time in 1946-47, so they are fairly scarce. I agree with Norman, a few years back a couple of these went for crazy/silly money, and that memory seems to have taken root.

Kent

[Joseph W Strickland]

Kent;

Yes capacitor values and their temperature stability were issues that could not be well addressed at the time these were built. Later tube types were capable of better gain with less noise too, so there were a number of factors that made these units performance not the best. Occasionally FM converters for the Japanese FM band are seen too and there is not much demand for them either.

Joe

[Jeff Barna]

Holy cow, expensive is right! I suppose...if you want to maintain strict originality. But what about any early FM tuner connected to the phono input? The Howard 482 comes to mind, because I used to have a couple (since sold) but any tube tuner should do the trick.

[Joseph W Strickland]

Yes an alternative complete FM tuner all the way to its detector output could be fed to the phonograph input of one of the early FM band Scott radios, but of course that would not be exercising the existing FM circuitry of the Scott. There are some other brands of early to late FM band converters around at far less money though, which would permit using the existing FM circuitry of the Scott receiver. Someone with some ingenuity and experience with VHF radio equipment could probably create their own converter for far less money using the front end from a tube type FM tuner that was built for the Post WWII FM band.

I suspect that most people with one of the early FM band receivers just accepts that they will not be able to tune in any useful stations on that old FM band and concentrates on the AM broadcast and short wave bands that the set can receive.

Joe

[Joseph Koester]

Since there is so little on AM radio I equipped my Philharmonic and All Wave 23 receivers with newer FM tuners.  I had a Sherwood, an H. H. Scott in the tube models and a small KLH tuner in solid state.  I wired them in to the AC power after the main switch on the Scott radio and they came on with the radio.  Was great to have good music on the Scott audio system, and I could just switch it out if I wanted AM or shortwave.

[Joseph W Strickland]

I am not sure if it is reduced in price, but there is one currently on eBay that has an asking price of $875 with bids coming in less than that so far. That seems much closer to the mark for something so seldom used or needed.

http://www.ebay.com/itm/E-H-Scott-FM-Converter-VERY-HARD-TO-FIND-SC...

Joe

[Jeff Barna]

From reading the description on eBay, I'm confused. Does this unit add FM to a non-FM radio, like an external tuner would? Or does it simply convert a radio with an existing pre-war (40mc) FM band to receive 100mc FM?

[Joseph W Strickland]

This unit is a converter so that the Pre-WWII radios that had the old FM band (about 42-50mHz) could receive the modern Post-WWII FM band (88-108mHz). It changes portions of the 88-108mHz band down to the tuning range of the Pre-WWII FM capable radios. E. H. Armstrong had a running battle with David Sarnoff of RCA over radio spectrum assignment to FM radio versus television. He already had an FM radio broadcasting network using the 42-50mHz frequency slot beginning in 1938. Sarnoff convinced the FCC to allocate the 42-50mHz frequencies to be used as television channel 1, which later became unused even for that purpose.

See: http://userpages.bright.net/~geary/fm/index.html

Joe