View Single Post
  #3  
Old 09-26-2013, 09:34 AM
dieseljeep dieseljeep is offline
VideoKarma Member
 
Join Date: Jul 2010
Posts: 7,562
Quote:
Originally Posted by wa2ise View Post
I converted an old hobby grade tube RF generator, a "Superior Instruments" model TV-50A (it's not that superior ), to an AM micro transmitter. It has 6 bands of RF frequencies, including the MW AM b'cast band.

The 12AT7 RF osc and modulator are original, the rest I built new. The 6AQ6 triode, similar to half a 5751 triode, with a mu of 70, serves as the audio gain amp and feedback mixer. The 6C4 is just a cathode follower, to feed the 12AT7 modulator triode, which has a low impedance input circuit. I used geranium diodes instead of the 1N4148's shown on the diagram.

The feedback loop is described at http://www.wa2ise.com/radios/amxmit.html
I always try to pick up some of that Superior Instruments equipment for some of my projects. They're a good source for parts and enclosures.
It's amazing to see what kind of designs, they came up with nothing but a bunch of junk and surplus parts. I have a pattern generator, using two acorn tubes and a 7193 high frequency triode as a rectifier.
Reply With Quote