gr300 setup

[wiz706]

I was just sold what I was lead to believe a complete working gr300
but what I received was a m120,gm300 power supply(with one radio power plug. and a zetron model 30 interface. can anyone help with the assembly advice of this unit?

also have a HLN3333A Rick can anyone send me the setup for this also?
or the part # for the service manual.

thank you
wiz706

[Will]

The GR300 used several different combinations.

The M120 is usally the receive radio, the GM300 is the TX radio.

Either the Zetron M30 OR the RICK is the interface unit.

On the RICK interface the RX radio gets power thru the 16 pin connector.

[wiz706]

thank you will

it came with the zetron m30 but i also have the rick
will the zetron get power to the rx radio?

[wavetar]

No the Zetron will not power the RX radio. They are good little units.

I actually prefer to use the GM300 as the RX radio, since it's accessory pins are programmable & thus it's more flexible.

There is an 10-pin terminal strip on the rear of the Model 30 which is used to interface to the radios.

Pin 1 - V+

Pin 2 - Ground

Pin 3 - discriminator input - connect to discriminator output of RX radio (pin 11 in M120/GM300 - jumper selectable for flat/filtered output. You want flat)

Pin 4 - Ground

Pin 5 - Tx audio output - Connect pin 5 to the microphone input of the transmitter (pin 2 in M120/GM300). Shielded cable must be used for this connection, connect the braid to pin 6.

Pin 6 - Ground (shielded braid point)

Pin 7 - PTT - connect to TX radio PTT input (pin 3 in M120/GM300)

Pin 8 - COR input - connect to 'carrier active sensor' in the RX radio (pin 8 in M120, programmable in GM300 but pin 8 usually chosen). Be sure to program the GM300 for "CSQ and PL/DPL" if you're using PL/DPL.

If you phone Zetron & ask nicely, they'll probably send you a PDF file of the manual if you don't have one.

Todd