GR300 Repeater?

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hfd921
Posts: 91
Joined: Sun Sep 18, 2005 6:15 pm

GR300 Repeater?

Post by hfd921 »

I have a GR300 repeater with 2 GM300's, Are the GR300 repeaters Narrow band?

If so, how can i tell if ours is?


We have 2 freq.

453.6000 and 458.6000 Will these two pairs work for the TX/Rx on the repeater or are they to far apart?

Thanks
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Bill_G
Posts: 3087
Joined: Thu Sep 17, 2009 5:00 am

Re: GR300 Repeater?

Post by Bill_G »

Not as far as I know.
Al
Posts: 1045
Joined: Tue Sep 04, 2001 4:00 pm

Re: GR300 Repeater?

Post by Al »

If you remove the gm300s there will be a model number on the bottom of the transmit PAs heat sinks. The GM300 was made in 12.5 and 25 khz spacing varieties IIRC. The model numbers will show whether they're narrow or wide.
Satelite
Posts: 670
Joined: Sat Aug 12, 2006 10:43 am

Re: GR300 Repeater?

Post by Satelite »

Hello:
You asked about the 453.6000 and 458.6000 freq spread being ok and yes that is the standard 5 meg split used to separate tx and rx .
The GR300 repeaters tx would be the 453.6000 tx and the 458.6000 rx would be the repeaters rx freq.
Bear in mind the portables and mobiles and base stations would be setup just opposite of the repeaters freqs to work with the repeater.
For example a portable used through a repeater would be tx 458.6000 and rx 453.6000 .
With the GR300 normaly a duplexer is used to keep the freqs separated for the gm300 rxcr and txcr.
If the gr300 has it then id suspect its tuned for the freqs you mentioned if it was in service as you listed freqs.
As stated by Al the GM300 was made in wide band 25 kHz and also a narrow band 12.5 kHz version.
The gm300 was one but not both in the radio such as for example the M1225 model did both in the same radio.
As Al said remove a gm300 and look at the model number on the bottom of the finned pa heat sink.
A model number M34GMC00D3A is a 10 to 25 watt 12.5 kHz narrow band.(8 channel )
A model number M34GMC20D3A is a 10 to 25 watt 25.0 kHz wide band. (8ch )
A model number M34GMC09C3a is a 10 to 25 watt 12.5 narrow band . (16 ch)
A model number M34GMC20C3A is a 10 to 25 watt 25.0 kHz wide band. (16 ch )
And if you find you have a M44 model then its a 25 to 40 watt .
So if you sub the M34 with the M44 and the matching balance of the model number above youd have
whats listed but at 25 to 40 watt rather than 10 to 25 watt.
Many times you will see the rx be a M34 and tx be M44 for higher wattage.
This is because rx doesn't tx so they sometimes use a less costly radio .
The gm300 your working with is in the 438 to 470 MHz spread.
The GM300 was made in other spreads too but with the freqs you posted it should be the model numbers above.
I do have several M44 narrowband GM300 mobiles that you could swap out with yours if they were 25.0 kHz wide band.
I have also seen a M120 or M10 used in these setups but normaly a GM300 but can be done with other models too.
Satelite
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