[Flexradio] RFC - Poor Man's Universal Controller Board

[ecellison]

Folks   I think I blew the ULN 2003 open collector chip out of my radio during the Belize DXpedition by trying to connect a relay in an amplifier directly into the radio on x2-7 without any buffering. Perhaps a spike or surge. Dunno. But it brings back to mind a project I suggested to Tony – KB9YIG who has done a fantastic job designing and refining kits for the SDR-1000 and is currently totally immersed in the SoftRock40 SDR.   At one time I had suggested a “Poor Man’s UCB” to connect dedicated and open pins to the X2 15 pin connector. It was shelved and deemed not necessary since users can plug just about anything into the X2 connector and experiment.   As a result of my experience, I’d like to ‘throw’ out an idea to create an inexpensive PC Board to protect the X2-7 output to control Amps etc, with a 5 v relay and provide jack for  a cold switch to ground for X2-10 PTT input. X2- pins 1 thru 6 could be brought out on a 6 or 10 pin Berg connector for readily available ribbon cables to interface the control lines to some external device, like a universal controller board or for experimentation by users in a breadboard. Having a little external board connected to the X2 connector perhaps with opto isolators would be a lot cheaper than replacing the ULN – 2003!   Anyone like to comment or tackle the design or parts for this board? Let’s kick it around a little!   Eric – AA4SW