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Guerrilla Radio (themarshallproject.org)
52 points by jgrahamc on Mar 27, 2015 | hide | past | web | favorite | 2 comments

I was a TDCJ officer for a couple of years (almost twenty years ago), and I am not a bit surprised to learn that some inmates have reconfigured their radios to transmit. I never saw a transmitter, but I did find a number of tattoo guns which were usually manufactured from the impedance matching transformers that were used to get radio reception inside the units. There are some very inventive people incarcerated and they obviously had a lot of time on their hands. The bit about the guards being clueless is largely true as well. Even though the radios were in a translucent housing so that they could not be used to conceal contraband, most officers were not trained or otherwise able to identify a radio that had been modified, especially if carefully done. Officers were instructed to confiscate any radio that was modified, but this policy was often ignored. Supervising inmate housing is one of the least desirable assignments. It's also often the case that if a housing unit isn't causing too much trouble that enforcement might be relaxed as it can be more disruptive than just letting some of it go. The design of many Texas prisons requires officers to walk down a long corridor ~24 to 34 cells per tier, allowing ample time for inmates at the ends to stow contraband.

A point of trivia here that isn't related to making AM transmitters but still interesting is that the type of radios that were really coveted by inmates were the ones that had a particular Sony PLL IC, I can't recall the part number but it is fairly famous for being a very good receiver with high sensitivity.


The Sony SRF-39FP is the "ipod of prison". It has good reception and runs on a single AA battery for 40 hours.

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