Google the K9AY controller by K9AY (the original). It uses +ve half wave rectified AC, -ve half wave rectified AC, Full wave AC and No AC for the 4 conditions, all going down the single coax. Works great.
- Paul KW7Y At 12:06 PM 4/15/2011, k2waltk wrote: >Hey all, > >I was wondering if anyone has built a circuit to control the switching of a >pair of two-wire reversible beverages, using only the coaxial feed to carry >the control >signals. The usual design calls for 3 DPDT relays. One relay is used for >beverage selection and one each for direction and unused port termination. >In other words, one relay for the NE/SW directions, another relay for the >NW/SE directions and the third relay is used to select between the two >reversible beverages. The truth table is straight forward, but the >circuitry to accomplish this is beyond this old, feeble brain addled with >advanced CRS. I can't figure out the circuitry (diode matrix?) to route the >control signals to the 3 relays. I understand how to isolate DC from RF, >through the bias-T method and I've seen designs using positive, negative and >AC to accomplish 'generic' remote antenna switching. Maybe I can use a >similar method to build the control switch back at the shack and the remote >relay box. Any of your suggestions, diagrams or references would be greatly >appreciated. > > 73 de Walt - K2WK > Gordonsville, VA > > > >_______________________________________________ >UR RST IS ... ... ..9 QSB QSB - hw? BK _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK
