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MOTOROLA CDM 1550 PROGRAMMING HELP


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Posted

Trying to add a fourth zone to my 1550. I want to add in the 5W GMRS channels (1-7). I had someone program my two repeater zones and my simplex 50w channels (15-22) and I’m trying to do this last zone myself. No experience with this btw.

I’ve added a picture of GMRS 15 personality on my current plug. Other than frequency, what needs to Change for GMRS channel # 1? 462.5625

I guess my biggest unknown sections are TPL Freq, Squelch Type, and Code.    Not sure what to put in these boxes for GMRS channels 1-7. 

TIA

 

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5 answers to this question

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Posted

PL will depend on what you other radios are. I would program it for CSQ in the drop down and leave it with no PL/DPL. Also under options you will need to pick low power. However I dont think low power on that radio is 5 watts. I think its 25/45. You may be able to change it in Radio Wide but I ran into this in the past. I think you need the low power radio (25 watts TX) to get to 5 on LP. 

They are solid radios but dont support all the low power stuff. 

Also that is programmed as narrowband looking at your screenshot. The is fine if your talking to midlands in narrowband but if others are wideband they will hear your audio quiter. Most will claim wide band is the only way you can use GMRS but narrow band will work for certain situations.

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Posted

In the "Radio Information" category, click on "TX Power" and set the minimum TX Power setting for 5 watts. Don't forget to save your work, periodically. Then, for each channel/personality, you need to click on the "Options" tab, and change the TX Power Level to "Low".

Assuming, you're referring to the interstitial channels. Obviously, change the freq to the appropriate GMRS freq i.e. Channel 1 - 462.5625 MHz through Channel 7 462.7125 MHz, for both TX and Rx., respectfully.

Channel Bandwith must be 12.5KHz ( FCC Requirement on the interstitial channels.)

Tx Squelch Type - TPL for analog CTCSS i.e. 156.7 Hz. The common travel tone is 141.3 Hz. The Code is a Motorola Tone Code and will correspond with the CTCSS tone freq you program/select so, don't worry about it if you don't know the tone Code. It's just a short cut to program the CTCSS tone freq. DPL is for digital tone code.

Rx Squelch Type - recommend you not program a tone so you hear everything on that freq. for now unless you only want to hear radios that transmit with the CTCSS tone freq you select. So, select CSQ for this setting.

Do you know how to add a new zone, or channels to an existing zone?

Let me know if you need any help.

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Posted

I just read my high power CDM1550LS. As suspected you can only go to 20 watts on low power. I dont think you can do what you want. On my low power (25 watt mobile) it allows down to 2 watts but on this one it wont go below 20.

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Posted
18 hours ago, nokones said:

Channel Bandwith must be 12.5KHz ( FCC Requirement on the interstitial channels.)

Channel bandwidth on the ORIGINAL GMRS interstitials (which predate FRS) is 20kHz (on 25kHz channel spacing)

Quote

§ 95.1773 GMRS authorized bandwidths.

Each GMRS transmitter type must be designed such that the occupied bandwidth does not exceed the authorized bandwidth for the channels used. Operation of GMRS stations must also be in compliance with these requirements.

(a) Main channels. The authorized bandwidth is 20 kHz for GMRS transmitters operating on any of the 462 MHz main channels (see § 95.1763(a)) or any of the 467 MHz main channels (see § 95.1763(c)).

(b) Interstitial channels. The authorized bandwidth is 20 kHz for GMRS transmitters operating on any of the 462 MHz interstitial channels (see § 95.1763(b)) and is 12.5 kHz for GMRS transmitters operating on any of the 467 MHz interstitial channels (see § 95.1763(d)).

12.5kHz only applies to what had been FRS-only (and still does for a true FRS radio): the 467MHz 0.5W now standardized as "8-14". Those are still on 25kHz channel spacing. All pre-FRS frequencies in GMRS are 20kHz on 25kHz.

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Posted

Oops, you're correct.  For some reason, I thought that the 462 interstitial channels were required to be narrowband like the 467s.  I guess I need to be a tad more careful when I read the rules.  Oh well, its only my second mistake in life.  Although, I do have a gazillion second mistakes.

So, the original poster has the option to program 12.5 or 5 KHz for the 462 interstitials.

Also, another second mistake, I stated in my previous post to go to the "Radio Information" section and click on the "Tx Power Tab".  The Tx tab is in the "Radio Configuration" Section" and he would need to click on the "Tx Power Level" tab, but, the software would not let me set the "Low" power level setting below 20 watts, as stated and depicted in the above posts, like the XTL5000s will.

Sorry for any confusion. I stand corrected and now better in the know.

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