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MASTR II Crossband Applications

Remote Receiver

A crossband MASTR II makes an excellent remote receiver. In this configuration, the MASTR II receives on a VHF band, and repeats what it hears on a UHF link frequency. A UHF receiver for each link frequency is used at the repeater's transmitter site to receive the signal(s) from the remote receiver(s), and transmits it back out on the VHF repeater's output frequency. A voter is often used at the transmitter site to choose the receiver with the best signal quality to re-transmit.

Split Site Repeater
A pair of symetrical crossband MASTR IIs makes an excellent split-site repeater, particularly for the 6-meter band, where the cost and size of a duplexer is prohibitive. This configuration uses a MASTR II that receives on 6 meters, and repeats the received signal onto a UHF link frequency. At the second site, the other MASTR II receives the link frequency and re-transmits what it hears on the 6 meter repeater's output frequency.

Crossbanding Information

I prefer to swap the transmitters. Some people have told me that swapping the receivers is easier, but I don't think so. Here's how to swap the trasmitters. It helps if the radios you want to crossband are operational and tuned up before you begin. The duplex modification should be performed before crossbanding.

Perform the following steps to both radios:

  1. Remove the 6 screws holding the exciter in, and remove the exciter.
  2. Unsolder the large black and red wires from the bottom of the PA.
  3. Remove the 4 screws that attach the PA to the rest of the radio. Dismount the PA from the rest of the radio. DO NOT DISASSEMBLE THE PA.
  4. Swap the exciters and PAs, and install them into the other radio. Be sure to keep the exciter with the correct PA, it will not be good if you mix these up. Pay attention to the polarity of the power cables when you reattach them.