so you wish to revive an old radio set?

[wireless man]

a few years ago, i wrote a detailed article on how to revive a vacuum tube tabletop radio. a great many people have found it useful. i think the crowd here may find it useful as well. the article deals with the most commonly found tabletop radios of the 40's-50's.

going back that many years, darwin had much more influence on how things were designed. millions of radios from that era were built as "transformerless". this means there is NO transformer isolating you from the power line. it was not intended that you go poking around in the radio while its plugged in. this design was commonly called the All American 5 but did exist in 4-8 tube variations. these AA5 style radios can kill you if you don't know what you are doing and are extremely common in the secondhand market.

if you have some technical ability and understand the dangers of owning a product that was designed when responsibility was placed on the buyer and not so much the manufacturer, then you may find this article interesting. i have quite a few of these AA5 radios in my home that i have restored and use on a regular basis.

enjoy.
http://www.instructables.com/id/How-to-fix-a-classic-American-AM-tube-radio/

 

[Stanley Doble]

Ha ha ha the AA5 also known as the gutless wonder. They worked well with the minimum of parts.

I like the console sets from the thirties where the chassis was alive with 400 volts including the control shafts. The only thing keeping the user from getting a lifter were the wooden knobs. If you went poking around the back you were on your own.

 

[FStephenMasek]

Ha ha ha the AA5 also known as the gutless wonder. They worked well with the minimum of parts.

I like the console sets from the thirties where the chassis was alive with 400 volts including the control shafts. The only thing keeping the user from getting a lifter were the wooden knobs. If you went poking around the back you were on your own.

Where did you get that baloney? It is not correct. The chassis and control shafts in radios with power transformers is not "hot" as in an AA5/6.

 

[FStephenMasek]

Go to antiqueradios.com or your local old radio club for good information.

 

[dhermann1]

I always rely on professionals to do that kind of thing. There's a good shop here in New York called Waves LLC that I always go to.

 

[LizzieMaine]

The thing with a radio, or any other piece of old electronic equipment is that you have no idea who's been in there before you. Unless you can compare a schematic diagram with the actual wiring in a set and see if there's discrepancies, it's best not go poking around. Normally any set with a power transformer is insulated from the AC line, but there are points on the chassis where you can get 350-400 volts of DC up your arm if you touch something you shouldn't. And if something in the set is miswired, voltage can show up where it isn't supposed to be.

Best safety rule: don't touch anything unless you know what it is and what it does and what it might do if it's not working properly.

 

[wireless man]

that's why i start that tutorial with the fact that these radios can kill you. getting zapped and working on old radios go hand in hand.

 

[John in Covina]

Test for voltage using your tongue just like a 9v battery! (NOT!):eeek:[angel]

What i'd like to do sometime is make a hand wound / built antenna for the AM.

 

[wireless man]

What i'd like to do sometime is make a hand wound / built antenna for the AM.

i think you may be referring to the diamond shaped antennas that had multiple turns of wire and usually sat on the radio? not hard to make at all. it's just wood and wire. cloth covered wire can be purchased from antique electronic supply. thin wire is easier to work with and cheaper if you're just using it for receive.

i'm sure the guys at antiqueradio forums could provide you with data on how much wire you need. the length of the wire is important if your antenna is to work right. there are some designs that use less wire but the tradeoff is they require you tune the antenna as you change frequency on your radio.

there is a commercial version of that design currently being made. it doesnt look as interesting but it works VERY well.
http://www.universal-radio.com/catalog/mwant/4316.html

i have personally used that antenna to pull in AM stations in a room that had over 100 flat panel displays and the computers that drove them.

 

[Stanley Doble]

Where did you get that baloney? It is not correct. The chassis and control shafts in radios with power transformers is not "hot" as in an AA5/6.

I was at the home of a collector some years back, he showed me a set he was working on. The chassis was "live". I don't remember the make or model but it was a console set from the thirties.

 

[John in Covina]

Much like assuming a gun is loaded let's say for safety sake assume things are hot until you've checked it somehow.

 

[FStephenMasek]

I was at the home of a collector some years back, he showed me a set he was working on. The chassis was "live". I don't remember the make or model but it was a console set from the thirties.

If it has a power transformer and the chassis is hot, there is definitely a significant defect, as it was not designed that way. Any old radio which has not been serviced by somebody who knows what they are doing should not be plugged-in. It is best to cut off the cord and throw it away.