Walt, Having done just that, here is what I did:
I have an Ameritron RCS-8V remote 5 port antenna switch at the support point for one of the Beverages. The other beverage termination is connected to this switch through a run of direct burial RG-6. Unused ports on this switch are not grounded. In the shack I have a bias-T to inject a control voltage to reverse either beverage when needed. One beverage controller is DX Engineering and one is homebrew and both have a bias T to handle the reversing relay voltage. At the moment, I use the control box for the Ameritron to automatically switch beverage directions. This is done with a diode matrix between the control box and the control lines going to the remote switch. The positions of the control box switch are labeled NE, SE, SW, NW. The 5th position is not currently used but will be used for another single wire beverage later this summer. The matrix either does or does not inject the reverse control voltage depending on the position of the controller switch. You need a diode in each control line to the remote switch plus another for each position that you want to inject the reversing voltage. This diode provides +12V to the relay on the bias T injector. In my case, NE is forward to Eu and SW is reverse and requires the diode to inject the reversing voltage. Each diode must point in the direction of the remote switch because the controller outputs +12V to the active position and must be rated for the relay current of 80-100ma and the control voltage with a safety margin. If you want, I can supply the schematic of the system I use. 73, Les W2LK On 4/15/2011 3:06 PM, 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
