Unknown RF modules

Monday 17th July 2000

Anyone know what these modules are?


I purchased them from Rocom Electronics which is a surplus electronics store in Clayton, Melbourne, Victoria, Australia. They cost me $1.00 each so I thought why not, since they seem to be some sort of UHF RF module.

There were 3 types of modules:

1. Transmitter (?) - has 3 coils etched into the PCB, all components surface mount, appears to be 3 instances of the circuit on a single PCB. The module has 16 pins, with about half connected to the backplane on the non component side of the PCB. There doesn't appear to be any crystal or way to adjust the frequency so perhaps this is a final stage rather than an oscillator. This board has "10A" near the top right hand corner, and a "10" inside one of the coils.

2. Receiver (?) - all components surface mount except 2 inductors on the component side, and 2 coils wrapped around formers on the backplane side. This one also has a coil etched into the PCB. 14 pins, again about half are connected to the copper backplane. This board is more complex than the transmitter board. This board has "H7B" in the middle, and a 7 in one of the coils.

3. Modulator and/or Demodulator (?) - I didn't get this one, but it had a couple of surface mount LM324 chips and other components, due to the layout and presence of a quad op amp I concluded this probably wasn't an RF circuit.

All 3 modules are a white solder masked (green) PCB with the pins coming off one side. Their size is about the same as a 40 pin IC, although the "transmit" board is slightly smaller.

Please email me at rowanWEB@sensation.net.au if you know what these are, or have any guesses!