New GMRS repeater on the air

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N3LLO

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In case folks here live in/travel through/visit Southern New Hampshire and happen to be GMRS licensees, I have put a repeater on the air that is open for anyone's use. Please keep communications courteous and legal (ID with your GMRS call sign).



 

n1das

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I'll have to give it a try. I live in the north end of Nashua.

Wide or Narrow bandwidth on your repeater? Lately I've been running all of my GMRS equipment in narrow mode to coexist better with the unlicensed bubble pack riff-raff on adjacent FRS channels 12.5kHz away from the GMRS primaries and the repeater inputs. I've often heard older "wide" bandwidth GMRS repeaters getting hammered by adjacent channel splatter from FRS radios on the upper FRS channels adjacent to the repeater inputs. The problem shows up when the FRS users happen to be using a tone that matches a tone in the repeater. All of my adjacent channel splatter problems went away when I switched my gear from wide to narrow mode.

I have TWO repeaters on 625. One of them is up in Enfield NH at an old phone company microwave relay site and the other is in my apartment in Nashua. The one in Nashua doesn't have much coverage because of the location (in my apartment) and it's meant for local play around use at home and at hamfests. Basically, if you can hear it, you can hit it. It's on DPL465N (no PLs used). It's getting hard to find a clean PL to use in urban areas, hence the use of DPL instead of PL. I've had to repair the PA in the transmitter a couple of times (Kenwood TKR-850, an early problematic Version 1 unit), so I don't trust it enough to put it at a site somewhere. This repeater in fact will NEVER be put at a site. It will always be at home, at a hamfest, or at other major events when I'm with GMRS-licensed friends of mine. I also keep it on DPL full time because whenever I take it somewhere, I don't want to use it on PL because of the risk of users bumping into another repeater in the local area that uses the same PL.

I plan on having my 625 repeater w/DPL465 on the air from my car at the NE ARRL hamvention coming up on 8/22-8/24 in Boxboro MA. Licensed GMRS users are welcome to use it at Boxboro.

462.625 DPL465N
11k0f3e "narrow" bandwidth mode
 
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N3LLO

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At long last the repeater is back on the air with a newly installed Antenex FG4607 antenna. I changed the tone to 88.5 for now, as to avoid the possibility of interference with an Arlington, MA machine.
 

n1das

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Hi Matt,

I'll try it again from Nashua on my way home tonight. Cool.

Have U tried my 625 repeater yet when you're driving thru Nashua? It's on DPL411 (was on DPL465) and back on the antenna instead of a dummy load. It has very local coverage only. If you can hear it, you should be able to hit it. I plan on having the repeater on the air at Boxboro this coming Saturday.

http://www.boxboro.org

73,
 

PeterGV

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Mont Vernon, NH
I'll try posting here, because I didn't get a reply on ScanCapeCod...

First... I'm new to using GMRS via repeater, so you'll have to excuse a dumb question: Your repeater is 467.625 IN and 462.625 OUT, right?

Second... Note that DPL of 255 doesn't seem to be a great choice. It's not one of the "standard" Motorola tones, and thus one couldn't program this tone into an XTS-3000 or XTS-5000 for example (please spare me the "Are those GMRS type-accepted radios" lecture, if so inclined).

Peter
K1PGV / WQDW930
 

n1das

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DPL255 is not a standard DPL code, i.e., it's not part of Motorola's set of 83 standard codes. However, it is part of the set of 104 standard codes of which Moto's 83 codes is a subset.

I recommend picking a code from Moto's set of 83 standard codes to help guarantee using a code that works plus have compatibility across different radio manufacturers. I'm using 411 in my local Nashua repeater (note VERY local coverage, I play around with it at home).

I had to eventually step up to the plate and use DPL instead of PL in my repeater because it's getting hard to find a PL tone that's "clean" in the area. Given that my repeater is somewhat portable and I take it to the major flea markets, I'm less likely to bump into another GMRS repeater in range of the flea market that uses the same PL I'm using. DPL solved all these issues. I had my repeater on the air from my car at Boxboro 2008 over the past weekend and was using it with my G/F. Worked great!

Try 244 instead of 255. DPL244 is a standard Moto code and part of Moto's set of 83 codes.

Also a word about nomenclature....the terms you'll hear are DPL and DCS. Motorola trademarked DPL, so the other radio manufacturers have to call it something different. Digital Coded Squelch (DCS) is the most common name for it in non-Moto radios even though they are the exact same thing. Basically, if it's in a Moto radio, it's DPL. If it's not Motorola, it's not DPL. Got it?

Motorola DPL information:
http://onfreq.com/syntorx/syntorx/pldplx.html

Good technical discussion of DPL operation: http://onfreq.com/syntorx/dcs.html
This is the best and most complete tech discussion of DPL I've been able to find on the web.
 
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n1das

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I'll try posting here, because I didn't get a reply on ScanCapeCod...

First... I'm new to using GMRS via repeater, so you'll have to excuse a dumb question: Your repeater is 467.625 IN and 462.625 OUT, right?

Second... Note that DPL of 255 doesn't seem to be a great choice. It's not one of the "standard" Motorola tones, and thus one couldn't program this tone into an XTS-3000 or XTS-5000 for example (please spare me the "Are those GMRS type-accepted radios" lecture, if so inclined).

Peter
K1PGV / WQDW930
You are correct with the repeater input and output freqs. Welcome to GMRS! I know that's a recent issue callsign because of the format of licenses issued through the ULS. Take a look at my GMRS callsign (KAE9013)...it's OLD! I've had mine since December 1992 and the format is like CB callsigns way back when licensing was required for 27MHz CB back in the 70's. My GMRS license predates the ULS and I had to apply for it using the old paper Form 574 used for Land Mobile license applications.

The repeater outputs are in the 462MHz part and the inputs in the 467MHz part of the GMRS allocation. It follows the same convention as Part 90 services do in the 450-470 part of the UHF band. And sort of like ham repeaters, when we refer to a GMRS repeater, we refer to it by the output freq only. We don't need to mention the +5MHz offset for the input because it's always +5MHz. Many of us also like to abbreviate 462.625 simply as 625. Bottom line is keep it simple and enjoy.
 
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PeterGV

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Thanks David, for the informative posts.

I dropped Matt -- the owner of the New Ipswich repeater -- a note since he doesn't appear to be hanging out in this forum.

Maybe he chose DPL 255 specifically because he didn't want to encourage the use of Part 90 equipment on his Part 95 repeater. In any case, I do realize that it's entirely his choice.

I'll report back what I discover, if I hear back from him,

Peter
K1PGV / WQDW390
 

PeterGV

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Reporting Back: Exchanged emails with Matt (N3LLO / WAJA763) the owner of this GMRS repeater. He's a heck of a nice guy.

He graciously agreed to change the DPL to 244.

Now, having said that, I'm still not able to raise his machine :-(

He's looking for a better spot for it... anybody wanna volunteer a bit of tower space in Southern New Hampshire for a good cause??

Peter
K1PGV / WQDW930
 

N3LLO

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New Ipswich, NH
Unfortunately, I tend to use an RSS reader to keep an eye out for new topics on a hand full of forums here.... That's why I didn't see the private messages.

I'm still seeking a good spot for the repeater. I'll have to contact a couple of hams in the local area... and have to take another look at some terrain maps on google.

- Matt
 
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