Motorola GR1225 Repeater Question

[Mattkuhar]

I recently acquired an old GR1225 from work, getting ready to set it up for GMRS use soon, but theres a question that i havent been able to find an answer to online.



Scenario: Im trying to get space on a water tower in town for the antenna.

I have the repeater setup with 16 "channels" all the same freq, but different PL/DPL on each one.

Is there a way to remotely tell the repeater to change the "channel"?



Im asking because if I can do this, I dont know if i will be given gate keys, or if a water company rep will need to accompany me to the site, and if its the latter, remote changing would be more helpful.




Matt

 

[dcr_inc]

If it is capable, It would be in the RSS in the accessory jack configuration. Look for channel steering..

 

[popnokick]

If I read what you want to do correctly, it is not changing the channel frequency but rather changing the PL/DPL remotely, but using the SAME channel everytime (?)

 

[Mattkuhar]

If I read what you want to do correctly, it is not changing the channel frequency but rather changing the PL/DPL remotely, but using the SAME channel everytime (?)

Correct, I have the programming done

EX. Channel 1 = 462.700 tx 136.5 rx 136.5
Channel 2 = 462.700 tx 77.0 rx 77.0

etc.


I just need to change the channel up/down on the repeater, remotely if possible.

 

[N4GIX]

Bear in mind that unless you are using separate antennas, the duplexer will be tuned to one specific frequency split only.

 

[Mattkuhar]

Bear in mind that unless you are using separate antennas, the duplexer will be tuned to one specific frequency split only.

yep, im aware on that limitation, thats why all 16 channels are set for the same Frequency, just different PL/DPL tones

 

[N4GIX]

yep, im aware on that limitation, thats why all 16 channels are set for the same Frequency, just different PL/DPL tones

Okay, I obviously missed that detail...

My BridgeCom BC-40DU repeater can support up to 24 PL/DPL tones for subscribers/groups to use. No channel changing required.

Even better, any of the 24 "subscribers/groups" may be remotely re-programmed over the air by the owner/trustee at any time.

It also allows up to 16 separate channels, but those are only controllable by the knob on the front panel.

 

[jeepsandradios]

To my knowledge the GR1225 does not support what you want to do out of the box. If you spend some money on a better control it may help. I ended up using the communications specialist TP-1000 controllers on all my GR1225 repeaters. They were reasonable on ebay and work OK via DTMF over the air programming. I can turn on or off a PL remotely. Think the GR also used the Zetron controller over time that also allowed that feature.

 

[Mattkuhar]

To my knowledge the GR1225 does not support what you want to do out of the box. If you spend some money on a better control it may help. I ended up using the communications specialist TP-1000 controllers on all my GR1225 repeaters. They were reasonable on ebay and work OK via DTMF over the air programming. I can turn on or off a PL remotely. Think the GR also used the Zetron controller over time that also allowed that feature.

Sorry for the long time between posts (had to find programming laptop)

The GR1225 that I have, DOES in fact offer channel steering, however, i dont know how to go about hooking it up (thru the ACC connector) do I apply voltage or Ground to make it change? thats what has me confused now.

attached is a picture of the config screen

 

[crazyboy]

Programmable Pins

Pins 4, 6, 8, 9, 10, 12, and 14 on the accessory connector are programmable. The function of each pin can be assigned using RSS. Information on the available functions and how to program them is contained in the RSS help screens and in the files in the Appendices section.

Pin 4 is an output only. It provides an active high to the 13.8 V dc supply (0.25 Amps maximum), otherwise it is pulled low via 10k ohms.

Pins 6, 10, and 9 are inputs only. They are normally pulled high inside the radio to 5 V dc via 4.7k ohms. To activate any of these input pins, it should be pulled low to within 0.7 V dc of ground.


Pins 8, 12, and 14 may each be programmed as either an input or output. If programmed as an input, the pin is pulled high to 5 V dc via 4.7k ohms. To activate the input, it should be pulled low to within 0.7 V dc of ground. If programmed as an output, the pin is normally pulled high to 5 V dc via 4.7k ohms. When enabled, the output goes active low. Maximum sinking current is 50 mA.

From repeater builder

 

[crazyboy]

Sorry for the long time between posts (had to find programming laptop)

The GR1225 that I have, DOES in fact offer channel steering, however, i dont know how to go about hooking it up (thru the ACC connector) do I apply voltage or Ground to make it change? thats what has me confused now.

attached is a picture of the config screen

With that setup you only have remote channel steering to channel two, you would have to set the other inputs to the other channels you want remote steering too.

 

[Mattkuhar]

With that setup you only have remote channel steering to channel two, you would have to set the other inputs to the other channels you want remote steering too.

The options I get in the drop downs are Channel Steering 0, 1, 2, 3, and 4.

If 1-4 correspond to channels 1-4, what would 0 do?

 

[bdheaton]

Channel Steering

The select lines don't select the channel number that is part of their name. The channel steering lines are setup in a binary fashion to select a total possible of 31 channels (max with 5 lines - I expect binary 00000 selects whatever is set on the front panel).

From the repeater-builder GM300 section.
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The 16-channel expanded logic board radios support "channel steering" through the accessory connector. You need to program the general-purpose I/O pins (6, 8, 9, 12, and 14) for "Channel Select". They turn into a binary coded input that allows you to select any of the possible 16 channels by grounding the appropriate input lines (assuming you've programmed the radio for active-low inputs). To select channel 1, ground the "Channel Select 1" line. Channels 1, 2, 4, 8, or 16 may be selected by grounding select line 1, 2, 3, 4, or 5 respectively. All other channels are selected by grounding multiple select lines. If you release all of these lines, the radio reverts to the channel selected by the front panel. If you select a channel that does not exist (i.e. 10 channels programmed and you select channel 16), the radio reverts to the channel selected by the front panel. Channel steering DOES work as expected on radios with more than 16 channels, i.e. you can select anything up to channel 31, as that's all that's possible with five select lines. This article tells you how to use channel steering.
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[Mattkuhar]

The select lines don't select the channel number that is part of their name. The channel steering lines are setup in a binary fashion to select a total possible of 31 channels (max with 5 lines - I expect binary 00000 selects whatever is set on the front panel).

From the repeater-builder GM300 section.
---------
The 16-channel expanded logic board radios support "channel steering" through the accessory connector. You need to program the general-purpose I/O pins (6, 8, 9, 12, and 14) for "Channel Select". They turn into a binary coded input that allows you to select any of the possible 16 channels by grounding the appropriate input lines (assuming you've programmed the radio for active-low inputs). To select channel 1, ground the "Channel Select 1" line. Channels 1, 2, 4, 8, or 16 may be selected by grounding select line 1, 2, 3, 4, or 5 respectively. All other channels are selected by grounding multiple select lines. If you release all of these lines, the radio reverts to the channel selected by the front panel. If you select a channel that does not exist (i.e. 10 channels programmed and you select channel 16), the radio reverts to the channel selected by the front panel. Channel steering DOES work as expected on radios with more than 16 channels, i.e. you can select anything up to channel 31, as that's all that's possible with five select lines. This article tells you how to use channel steering.
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SWEET!! Thank you so much!!!!! I now have a project ahead of me, lol