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Replying to Seeking feedback on GMRS plan

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Posted 09 September 2019 - 04:47 PM

Jumping in: I ordered an RT-97 programmed for GMRS. It just got here, so I haven't tested it out very thoroughly (I also just moved into a new house, so I'm still setting up *everything*). But I can confirm it works for GMRS. Plugged it in, set it up with the pre-programmed CTCSS codes into a pair of my GMRS-V1s, and had a repeater online in about 10m.  I haven't even unpacked the computer that will let me reprogram the CTCSS codes - I spent more time trying to figure out what codes they'd put in than anything else.


More when I have more time to put it through its paces.


Posted 09 September 2019 - 02:54 PM

...put together my own repeater using a pair of... ... M1225's....

I bet a pair of P1225s would make a great portable repeater and they are dirt cheap nowadays.


Posted 09 September 2019 - 02:37 PM

In any case, as soon as I can free up $400 I'm going to order one. If I have to put it on my bench and re-tune it with my service monitor, so be it...

IDK, for $400, to only get 10 watts, I rather put together my own repeater using a pair of TK880's or M1225's then I have options to run 10-25/25-40 watts and still have $ left for the feedline and antenna.


Posted 09 September 2019 - 02:09 PM

Ian, I have only reports from a few people who have ordered and received +5 MHz split, with the correct Rx/Tx frequencies programmed and tuned.


I did point out to Retevis directly that there was absolutely no reason why they couldn't tune their repeater to use our convention of Tx low, Rx high. Since they never replied to me directly, I can only assume that from the reports I've read that Retevis at least took my comments to heart. It was from suggestions and comments made to them that they now offer 5 MHz split now.


In any case, as soon as I can free up $400 I'm going to order one. If I have to put it on my bench and re-tune it with my service monitor, so be it... ;)


Posted 08 September 2019 - 07:02 PM

N4gix, do you have any supporting information on the RT-97 being GMRS capable?  Because the way they sell it, you'd have to listen on 462 and transmit on 467.


I really hope that you're right about this thing...  :D  


Posted 08 September 2019 - 02:19 PM

2) repeater. I thought duplex repeaters were only for HAM licenses? I really hate the thought of that 90 sec transmission fiasco with using a simplex repeater, but what other duplexer unit can a GMRS licensee (me) use?

Repeaters are permitted on eight channel pairs in the GMRS allocation. They have up to 50watt output, and their antennas must not be higher than 20' above their mounting structure (building, tower, etc.)...

If you truly want something portable, you might consider the new Retevis RT-97 portable repeater. Despite some confusing language, they are in fact able to program them for the correct repeater +5MHz split, 467.xxx receive and 462.xxx transmit.

A pair of hams in England* did a range test with the repeater running off a parked car's battery and using the antenna on the car. They easily got 7 miles range from their hand held radios. More range of course could be achieved by hoisting an antenna into a tree. smile.png


The RT-97 is not simply "two portables in a box" but instead is a properly designed transmitter and receiver in a custom aluminum housing providing very robust shielding between them.



Posted 06 September 2019 - 11:44 AM

Interesting discussion, gentlemen.

There is a specific language in Part 95 that specifically, very clearly prohibits simplex repeaters on FRS and CB. There are no such statements in Part 95E. I will find the relevant references later, when have time.


Regarding the Argent Data repeater, it is not a repeater, but rather a repeater controller. It uses your (certified, of course!!!) radio to receive, record and transmit if asked, so it does not have to be Part 95 certified. The default setting on ADS-SR1 is to record and do nothing. Only when DTMF "0" is heard on air, then the last recording is transmitted out. Of course, you can configure it as a true parrot repeater and annoy everybody in the range of 5 miles from your location. To deploy such system in urban area would be uncourteous at least.

I use it when camping and hiking deep in the woods. Car with ADS-SR1 connected to TK-880 is parked somewhere (preferably high, but often not). Family is spread out and left for they own devices, some at the river bank, some sleep, some cook, some carve spoons out of pieces of wood. I could be 2 to 7 miles out from the camp. When I need to check on kids and adults, I call out and wait 20-30 seconds for them to answer. No answer heard, I send "0", and TK-880H blasts out my last transmission at 40W, now I've got everybody's attention.


Posted 06 September 2019 - 09:24 AM

I think the moral of the story is simplex repeaters are, with the exception of some testing, and niche applications, very tedious and awkward to use practically. If someone is looking for a reason not to invest in a regular repeater, a simplex repeater isn't it. 


From experience. I built an interface and used echo station to try one out some years ago. 


Posted 06 September 2019 - 07:43 AM

...It also stands to reason that if simplex repeaters were not allowed manufacturers would not be submitting the equipment for certification nor offering them for sale.....

Reason, the law, the applied law and the FCC may or may not coincide. All I am saying is that, unlike regular repeaters, there is no basis in the regulations to state that simplex “repeaters” are explicitly allowed. Further, in point of fact, they are really not repeaters at all. They rebroadcast via store and forward technology.

Repeater station. A station in a fixed location used to extend the communications range of mobile stations, hand-held portable units and control stations by receiving their signals on one channel (the input channel) and simultaneously retransmitting these signals on another channel (the output channel), typically with higher transmitting power from a favorable antenna location (typically high above the surrounding terrain).


In addition, as far as I can tell, Argent Data Systems, the manufacturer of the "repeater" noted by @Guest_Mark Lewis_* has not certified the ADS-SR1 for GMRS, or any other service. In fact, they do not appear to even have an FCC Grantee Code. On top of that, the manual for the ADS-SR1 states:

Legal Issues

Legal restrictions on the operation of a simplex repeater depend on the radio service used (i.e., amateur, commercial, FRS, MURS, etc) and vary from country to country. Interpretations of specific rules vary as well, and their applicability to operation of the ADS-SR1 may depend on which specific features are used. It is the responsibility of the end user to ensure that they operate within applicable regulations.


Posted 06 September 2019 - 06:56 AM

The rules plainly state repeater stations may be operated by remote equipment PERIOD. The rules do not make any stipulations on how that automatic control is implemented other than explicitly stating what manners are prohibited in 95.345 and 95,347. It also stands to reason that if simplex repeaters were not allowed manufacturers would not be submitting the equipment for certification nor offering them for sale.


I don't know about you, but I was personally involved in bringing to the Commission's attention a device being marketed for use in a prohibited manner. Shortly after my call the company removed the device from their product line. The device that was offered was a repeater being marketed in a band where the only permitted communications are base to mobile and mobile to mobile. Base, or fixed location to base communications is specifically prohibited.

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