Relay to switch polarizer between Analog & MPEG receiver

[Sadoun]

Could you use a relay to switch the antenna polarizer between the analog receiver and the Fortec? using the 12v output of the Fortec to turn the relay on when the Fortec was on?

Yes, you could. Use a DPDT relay and have it switch the power and servo signals. Wire the ground in common. The analog receiver should be wired to the side of the relay that is closed when the coil is unpowered.

DPDT means that there are two independent circuits, and each circuit has a middle terminal that can connect to one of two other terminals, depending upon whether the relay is powered or not.


1. Go to Radio Shack and ask for a DPDT, 12V coil relay. They've got several. If you get one with big spade terminals, you can use crimp-on quick-disconnect terminals
for the wires and not have to do any soldering. The person who works at the store can help you out to find all this stuff.

2. Wire the terminals for the coil to the 12V terminal on the digital receiver. One side of the coil (any side) goes to ground, the other side to the 12V terminal.

3. Look at the relay package to figure out the other terminals. Wire the center terminal of one circuit to the polarizer power connector. Wire the Normally-Closed (NC) terminal of this same circuit to the analog receiver. Wire the Normally-Open (NO) terminal of this same circuit to the digital receiver. Again, this is all for the polarizer power in each case.

4. Following the same logic as above, wire the other circuit of the relay to the polarizer servo signal.

5. Wire the polarizer ground terminals from both receivers as well as the polarizer all together.

6. That's it. Make sure to insulate any exposed connections to avoid a short circuit.

By Zoyburg (rats@attib.com) :lol: