MASTR II Crossband Applications|
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
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
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:
- Remove the 6 screws holding the exciter in, and remove the exciter.
- Unsolder the large black and red wires from the bottom of the PA.
- 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.
- 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.