View Full Version : "Foot Warmer" Amp anyone heard of?


bsujeep
02-19-2009, 10:47 AM
I saw this on CL and had little info. Does anyone know anything about it? This is the only picture and I may not be able to get any more.

tshoejohn
02-19-2009, 11:00 AM
Could be some kind of "illegal" ham radio amp:

http://www.urbandictionary.com/define.php?term=foot%20warmer

Celt
02-19-2009, 11:04 AM
Linear Power Amp for CB/HAM use. Not intended for audio and were common in the 70's during the CB craze.

tshoejohn
02-19-2009, 11:07 AM
Pretty sure it’s an illegal amp

http://reviews.ebay.com/Citizens-Band-Glossary_W0QQugidZ10000000000953581

…..Foot Warmer - see Linear Amplifier……

…..Linear Amplifier -An illegal device used to amplify the radio frequency energy output of a CB radio to a level higher than allowed by the FCC…………..

tshoejohn
02-19-2009, 11:08 AM
There might be some cool parts / tubes in it?

Celt
02-19-2009, 11:25 AM
RF related parts and sandsistor as I recall. I wouldn't bother.

similost
02-19-2009, 11:33 AM
ok.. so I guess they call it a foot warmer, because you hide it under your desk, or under your dash... but my question is.. if it's illegal to use, are they not illegal to own? so would that mean they are legal or not to sell? (wondering since they are posting on CL, where even the FCC can read)

zenithfan1
02-19-2009, 11:40 AM
I would cause trouble with that....:D.....Hmmmm...might try to find me one.

mhardy6647
02-19-2009, 11:50 AM
ok.. so I guess they call it a foot warmer, because you hide it under your desk, or under your dash... but my question is.. if it's illegal to use, are they not illegal to own? so would that mean they are legal or not to sell? (wondering since they are posting on CL, where even the FCC can read)

Not illegal to own, and only illegal to use on the 11 meter (CB) band in the US. You can (or at least you could) use one legally as a linear amplifier for the 10 meter ham band if you were so licensed. In CB's heyday, linear amps were often referred to as "heaters" as well as footwarmers.

BTW, the output tubes in many of the broadband linears can make excellent hifi outputs. Many are directly heated triodes and are almost obscenely linear amplification devices in Class A. Plate voltages (and plate dissipations) can be terrifyingly high for some of them. The cheap linears used and sold for CB use often used a bank of (2 or 4) 6JE6/6LQ6 color TV horizontal output tubes. One of the big McIntosh tube power amps did, too (push-pull parallel)... was it the MC-300?

bsujeep
02-19-2009, 12:09 PM
Interesting, he called it an H F amp. I had no idea what it was, but it looked interesting. If he was a little closer I would go check it out just for fun. I remember when my uncle was into CB's in the 70's and had linears. One of his friends had one so hot it would burn your hand to touch the whip antenna when the mic was keyed.