1. This is me at my mini lathe making a brass radio part.

    Richard

Zenith Designed

Tube AM Broadcaster, Transmit music to your Radio. Now your antique radio can play all of the same programs it did when it was new! With your CD, Ipod or cassette tape player, phonograph or high output microphone, You can even play a musical instrument. through it. this two tube transmitter becomes a miniature AM broadcasting station, patterned after the 1939 Zenith model S-7000 Wireless Record Player. As per the F.C.C rules Part 15 this is a perfectly legal transmitter And you need no license to use it. The rules state that the transmitter may only transmit 100mw input into a 5 meter antenna and transmit no farther than 200 feet and this transmitter meets all these rules.

AM Transmitter

The Transmitter

Transmitter is built on a wood box with an aluminum top and painted with auto paint and clear coated with an auto clear and will stay nice for a long time being as hard and tough as it is. The real gold lettering is real gold on a clear tape made by Brother. Tubes are always American made

AM Transmitter

The Antenna

Its 18 foot long and pretty much all you will need, but you can add more if you like, Some radio collectors place the transmitter behind a console radio and hide the antenna behind the other radios. touching the antenna changes the frequency a little so get it where you want it where it will not be touched anymore.

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The Power Transformer

As you can see its made by Hammond in Canada. they build a very good transformer i think, but some praise them and some cuss at them, then again the ones that cuss at them may have screwed up and shorted one out. it only supplys 125 volts but its rectified by a bridge rectifier and then into a capacitor input and the final voltage is 185 volts, just right for this transmitter.

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The Circuit

Some of the parts are American antiques like the sockets, some parts are Chinease. but whatever part i use i try hard to use only well made ones. The coil i wind myself on what was a horizontal TV Oscillator with a ferrite adjustable core that drifts very little and will not even be noticed on the AM broadcast band.

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Audio Patch cord

This is RCA to 3.5mm plug type to go from most radios Ipods and CD players Its chinease made but well made and will last if not abused. It is 5 foot long

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The Specifacations

    Paint; PPG auto blue metal-flake with hardener, auto clear coat with hardener. The paint is tough!. This transmitter will always look this good!.
    Power 115-120 volts AC
    Power usage 5 watts
    Size. 5 1/4" High.. 7" wide.. and 7" deep.
    Tubes 1. 12AU7 1. 6SA7
    Frequency 760 to 1550KHZ. default setting is 1000KHZ
    Its easaly tuned with an allen wrench or hexagon radio slug tuning tool.
    (Will gladly set it to transmit on any frequency you want)
    (PLEASE tell me what frequency you want to use?)
    Power in 1 volt peak audio power (headphone volume)
    Power out 100mw
    Audio. Grid modulated.
    Antenna 18 foot of #20 wire
    Frequency drift +- 20 cycles after warm up.

Rich Amps