AM Transmitter 1

Schematic: http://i263.photobucket.com/albums/ii151/cameramanlink/AMTransmitter.gif
Homemade AM transmitter built from a kit from http://www.tubesandmore.com
This simple transmitter uses a 12SA7 pentagrid converter that oscillates and is amplitude modulated using its middle grid. Audio is connected from the CD player to this grid. The sound heard is from the radio connected directly to the camcorder as shown in the video. The radio is homemade as well, and a video about it can be seen on my channel.
http://www.freewebs.com/cameramanlink

Category:

Science & Technology

Tags:

• homemade
• am
• transmitter
• vacuum
• tube
• radio
• receiver
• amplitude
• modulation
• superheterodyne
• 12sa7
• aa5
• all
• american
• five

[mpingo91]

Looks like the signal it transmits is high quality. Could you get us the coil data, please?

[CameramanLink]

@mpingo91 It's the oscillator coil P-C70-OSC from Antique Electronic Supply. It's a generic replacement.

[israelgleza]

Hi CameramanLink, In Mexico we have 127V AC in line, I can use AC domestic line directly instead transformer?

[CameramanLink]

@israelgleza NO!!! I repeat, NO!!! You will DIE if you do that unless you take the necessary precautions in wiring and insulating. You MUST USE THE TRANSFORMER!

[albundy316]

Good work! What is maximum distance between transmitter and receiver?

[CameramanLink]

@albundy316 Thank you. I have been able to go about a block and get reception, but it really depends on location, angle, and what's in the way. This is good as a whole-house transmitter, but won't be good for much further than that because the quality drops off quickly.

[israelgleza]

Ah, OK. I'd say that 127 VAC line because the transformer output is 125 V for plate and grid tube. Obviusly, I need 12.6 V transformer for filament tube. My english isn't good. Thanx.

[CameramanLink]

@AllAmericanFiveRadio Thank you. This was my first attempt at a transmitter because at the time I had no idea how they worked. I saw this kit and thought it would be a good learning experience.

[CameramanLink]

@FelixTheHouseFreak Yes, I think to some extent the stability can go off. This type is very simple and is meant more as a demonstration that you can transmit an AM signal using only one tube. I have had it on for extended periods of time and it seems to work fine for me. I would recommend this kit because it's simple, fairly cheap, and easy to build with good results.

[FelixTheHouseFreak]

I hear this transmitter is supposed to have stability issues. What is your opinion?