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Petitioning to get a few VHF frequencies added to GMRS


Hans
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30 minutes ago, Wrjy836 said:

Someone asked what the benefit would be. It would be nice to be able to set up a repeater without having to buy expensive bandpass/notch filters. A one-way crossband repeater using VHF as the input is a lot easier to successfully set up. 

Exactly. Even just basic cross-banding through a vehicle's mobile would be a plus. Also, there have been situations where VHF would propagate better than UHF. 2M was propagating much better for me but not everyone had an amateur license. We used MURS but the radios were not part certified for it. I doubt the FCC will ever include VHF in GMRS but hope springs eternal.

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2 hours ago, Hans said:

Exactly. Even just basic cross-banding through a vehicle's mobile would be a plus. Also, there have been situations where VHF would propagate better than UHF. 2M was propagating much better for me but not everyone had an amateur license. We used MURS but the radios were not part certified for it. I doubt the FCC will ever include VHF in GMRS but hope springs eternal.

There are already illegal cross band repeaters operating between MURS and GMRS for exactly the reason above.

I think it would be a better bet going digital, DMR. There are SFR, single frequency repeaters that take advantage of the dual time slot nature of DMR. The repeaters don’t need expensive tuned cavity filters. No new frequencies are necessary either.

Being narrow band, 12.5KHz wide channels, it might be possible to spilt one or two of the existing wide band repeater frequency pairs into two channels. One or two SFR’s could operate on one of the existing analog input frequencies and the same with the output frequencies. Thus one old analog repeater frequency pairs could accommodate up to four digital SFR systems.

One could “sell” this to the FCC as making better use of the current spectrum while simplifying the the system hardware making it more accessible to the general public.

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20 minutes ago, MichaelLAX said:

Where?

I'm aware of one that previously served as a repeater RF link in New Mexico but was decommissioned once internet connectivity was established at the remote site. It was approximately an 80-mile shot using a yagi on at least one end but was very susceptible to noise and presumably tropo ducting.

I'd be very supportive of adding high-power operation on the MURS frequencies to GMRS, in the same way that GMRS shares frequencies with FRS.

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37 minutes ago, Lscott said:

There are already illegal cross band repeaters operating between MURS and GMRS for exactly the reason above.

I think it would be a better bet going digital, DMR. There are SFR, single frequency repeaters that take advantage of the dual time slot nature of DMR. The repeaters don’t need expensive tuned cavity filters. No new frequencies are necessary either.

Being narrow band, 12.5KHz wide channels, it might be possible to spilt one or two of the existing wide band repeater frequency pairs into two channels. One or two SFR’s could operate on one of the existing analog input frequencies and the same with the output frequencies. Thus one old analog repeater frequency pairs could accommodate up to four digital SFR systems.

One could “sell” this to the FCC as making better use of the current spectrum while simplifying the the system hardware making it more accessible to the general public.

At one time, I was against DMR on GMRS. I have since changed my stance.
 
Your ideas are good and valid but ignore the situations where one band is going to propagate better than the other. I ran into that surprisingly more often than I expected over the years. Additionally, there are situations where cross band is cheap and easy (ex. handheld <-> mobile <-> handheld). Instead of VHF or DMR, why not both? (Insert WhyNotBoth.jpg meme here.)

Edited by Hans
grammer
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5 hours ago, MichaelLAX said:

As an admitted Kenwood fanboy, can I open up my two dormant TH-22a’s for MURS?

There are plenty of Kenwood commercial HT’s that cover MURS. Most of the VHF ones work from 136 MHz to 174 MHz. That covers the complete Ham 2M band, MURS, NOAA weather channels, VHF marine and railroad analog. In my collection  of HT’s that cover the range are the TK-2000, TK-2160, TK-2360, TK-2140, TK-2170, NX-200. These are all 5W/1W with wide and narrow band FM. The TK-270G officially goes from 150 MHz to 174 MHz but can be pushed down into the Ham band.

None are certified for MURS. Some “might” be legally used since they were certified before MURS was created. This is a very gray area. In any case one has to watch the bandwidth and power levels. There are not many MURS specific radios available. 

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On 11/8/2018 at 1:04 PM, WRAF213 said:

 Mobile repeaters are not allowed within the rules of GMRS, so any device that is a repeater intended for mobile installation won't get type acceptance. This has little to do with the licensee, because there's no 'insurance policy' of a test of good operating procedure knowledge with a GMRS license. The responsibility falls upon the manufacturer to prevent misuse of GMRS radios, such as mobile installation of a repeater or the interconnection of a simplex repeater controller. The licensee would have to go out of their way to circumvent protections against misuse, such as nonstandard connectors or designs for a fixed operating location.

 

Does anyone know if the Retevis RT97 really is type accepted? If it is it clearly come equipped from the factory to be run out of a standard 12 volt power source, ie a "cigarette lighter".

Just playing devil's advocate. :)

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On 10/26/2021 at 9:20 PM, Hans said:

Additionally, there are situations where cross band is cheap and easy (ex. handheld <-> mobile <-> handheld). Instead of VHF or DMR, why not both? (Insert WhyNotBoth.jpg meme here.)

GMRS was built specifically so people didn't have to worry about band propagation. GMRS was essentially created to be "plug and play".  Turn on, select channel, push button, talk, done.

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1 hour ago, WRFP399 said:

Does anyone know if the Retevis RT97 really is type accepted? If it is it clearly come equipped from the factory to be run out of a standard 12 volt power source, ie a "cigarette lighter".

Just playing devil's advocate. :)

The Retevis RT97S is an exciting new UHF repeater certified by the FCC for use on GMRS! The Retevis RT97S has FCC ID 2ASNSRT97  Retevis RT97S Portable GMRS Repeater – myGMRS.com

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On 10/28/2021 at 4:26 PM, TOM47 said:

The Retevis RT97S is an exciting new UHF repeater certified by the FCC for use on GMRS! The Retevis RT97S has FCC ID 2ASNSRT97  Retevis RT97S Portable GMRS Repeater – myGMRS.com

I've had my "RT97" for several years, although I've since reprogrammed it for 70cm ham use. I have a 50' telescoping mast and antenna I can deploy in the field to help support our ARES group when needed.

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2 hours ago, n4gix said:

I've had my "RT97" for several years, although I've since reprogrammed it for 70cm ham use. I have a 50' telescoping mast and antenna I can deploy in the field to help support our ARES group when needed.

Did you need to re-tune the cavity filters?Somebody else said theirs was tuned rather wide so they could change frequencies without having to mess with the filter tuning. I find it hard to believe it works that good without getting the RX de-sensed because the notch isn't that deep when not tuned narrow enough.

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On 11/1/2021 at 3:52 PM, Lscott said:

Did you need to re-tune the cavity filters?

Absolutely! Changing from 462/467 MHz down to 447.975 MHz was a "bridge to far..." Having 16 channels is useless as the duplexer is simply too tight to allow, especially for multiple GMRS frequency pairs. Fortunately I have three analog service monitors in my shop. I wish I could afford a digital service monitor!

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So while I understand the want / need of a vehicular repeater for extending range of a portable radio, if you do this on MURS you open up the possibility of a non-licensed operator gaining access to GMRS repeaters without that person even knowing they are doing so.  Some MURS operator with the right frequency and PL code would access your vehicle repeater just like you would be. 

This is why you also can't do an in-band repeater on a FRS frequency.  Joe Blo with his/her blister pack radios is suddenly on the local GMRS repeater.  Yeah, that's not gonna go over too well. 

 

And honestly.  If you need access to a GMRS repeater that often that you NEED a vehicular repeater to gain that access, you need to be on a commercial frequency and not GMRS.  Of course at that point, you can get a VHF and UHF or whatever and have a vehicular repeater.

But the issue I see with all this is having two different radio services linked.

 

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