Some good news, I was able to get the maxon radio programmed! I could not get the interface cable I built to work, but I was able to manually make a hex file of the programming software EEPROM preview and manually flash the I2C EEPROM with a CH341a programmer. I added a speaker too since the radio h...

Although a bit off topic to the reverse engineering project, I recently went on a detour on my way up to a graduation party. One of my stops being in Elm Creek, Nebraska – the former home of CD&F. In the first picture, you can see one of the former CD&F buildings located on 202 East Front S...

Although a bit off topic to the reverse engineering project, I recently went on a detour on my way up to a graduation party. One of my stops being in Elm Creek, Nebraska – the former home of CD&F. In the first picture, you can see one of the former CD&F buildings located on 202 East Front S...

I'm not having much luck with mine. So far I only have three tone filters working, and one of them only works at 10Hz below the specified tone frequency. 688.3 (replaced chip and reflowed joints; works but only at 678 and lower for whatever reason) 726.8 (works) 767.4 (used to not work, now randoml...

It's currently a WIP on getting it working right now. The receiver is a D.L. Johnson EF-3410 UHF receiver, instead of the later Maxon radios. I wasn't able to get it, but I found out how to bypass the audio output from the radio to the audio input to the tone filters. It was originally wired for 23...

Very cool to see another person interested in analog siren controls like me. I saw you mentioned using the LM567 in a redesign, I'm working on a full controller using that exact chip. An even older decoder, the Federal Signal Siratrol, used no ICs at all and used a chunky LC oscillator for tone dis...

I've been waiting for someone to do something like this! Best of luck on it! I've got a large CD&F if you're interested in tackling that. I've got a 1991 Plectron / Federal Signal SC controller I'm trying to get working; I might be interested in some help with reverse engineering the tone filte...

I've been waiting for someone to do something like this! Best of luck on it! I've got a large CD&F if you're interested in tackling that. I've got a 1991 Plectron / Federal Signal SC controller I'm trying to get working; I might be interested in some help with reverse engineering the tone filte...

Hey everybody, I acquired a smaller yellow box CD&F not too long ago and decided to see if I could retune the receiver onboard for ham/amateur frequencies (Spoiler, I did it!). What that all led to was reverse engineering the entire thing. The article is still being updated by me as I discover n...

For anyone else coming across this, I stumbled upon this video in which there are some (albeit rough) measurements: https://www.youtube.com/watch?v=4laOeraDF_I For those who don't wanna watch the whole video, here they are: Total height (From the service manual) - 100 to 102" Chopper - 15"...