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Seeking feedback on GMRS plan


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#1 Guest_Mark Lewis_*

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Posted 03 September 2019 - 09:33 PM

I am new to the amateur radio world and only used CBs infrequently. I'm not interested in listening to the constant traffic of the CB. My family won't get into HAM so- GMRS seems to be my best option. In saying that, I have something of a plan to develop for my family that I would like to expand into my community. Therefore, I have several questions that I would like help answering as I begin.

 

1) Getting my license. a) I am aware that my close family can be covered under one license, but how far is that extended? I haven't read too deeply into how I place people on my license, and how they might be related to me. Please, direct me to the appropriate information. I am very active within my church (5013c religious non-profit) that uses mobile radios from time to time for public community activities, can my license be used within this group (i.e. the close family question) or does the organization need its own license? If so, where would that information be found?

 

2) Radios. I have my eye on the (https://midlandusa.com/product/mxt275-micromobile-two-way-radio/) Midland MXT275 15w mobile radio that would like to make back pack portable with rechargeable battery pack and whip antenna. My concerns are a) the unit getting burning up inside my pack while using it;  B) using the best/safest/lightest/versatile rechargeable battery pack available; c) the most appropriate antenna that would give me respectable reception while carrying.

 

3) Repeater. I've considered using a simplex repeater (https://www.argentdata.com/catalog/product_info.php?cPath=27&products_id=98&osCsid=18AQ4OPGf1tOsN4yF2kZB2) specifically the ADS-SR1 Simplex Repeater unless there are better, less annoying ways of connecting devices for maxim range. I would hope to reduce what I understand is the annoying and distracting repetition of messages with the simplex repeater. I have four places I would put some repeaters for some extended coverage. I would use ac as the primary power source but would hope to utilize rechargeable batteries with solar power back up.

 

4) Antennas. The area in which I live is 140ft above sea level at its highest point. The major obstructions are wooded eras and the occasional bridge span. I would place overlapping repeaters and antennas at four (two locally, site #3 (40 miles away), site #4 (55 miles away) locations because there are none (according to this site's map). While I have found the potential for others, I haven't contacted the owners because I'm just getting started. Finally, how would I ground these antennas and protect them from lightning strikes?

 

5) Mobility. I would very much like this to be plug and play. Install in vehicle. Put in pack. Bring home. Repeat. I realize the range and power consumption will vary, but this is something REALLY important to my plans and goals.

 

6) Inexpensive and Versatile. I don't necessarily need new radios, but I'm not all that technical. Perhaps I could learn a few hacks and tricks, but I need a clean and simple "set it and forget" system. Any older radios that still work well? Any features that I should be looking for such as "repeater capable" devices? 

 

7) Purpose. General communication. Community development. Make friends. Connect with family. Safety and security. Disaster relief. the apocalypse?

 

 

Thanks for taking a look at my post. I hope to have my license within the month. I would to start playing around with this setup fairly soon. Please, label your responses by question and provide links with your responses. I'm quite this information will be helpful to others as well.

 

revmark96@gmail.com



#2 zackandmack

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Posted 04 September 2019 - 12:02 PM

Hello Mark,

 

There is older equipment that is both Part 90/95 compliant, or rather, grandfathered in.  Programming could be an issue with this equipment, but the software does exit.  It sounds like you are developing a very nice plan for the community.  

 

Where I live, a very robust communication plan has developed in response to both wildfire danger and the power company taking to actually turning off power for entire regions during fire danger events.  Neighbors have turned to GMRS as a method of communication. Local amateurs are holding seminars in guiding people through the license process, etc.  There are equipment recommendations and I have to say decent GMRS equipment is rather sparse.  There is Midland, of which is a re-badged Luiton, Chinese made radio.  There is Baofeng and the jury is still out on that...and there is the older equipment that I mentioned above.

 

Good Luck

73

N6TDG/WRDZ552



#3 BoxCar

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Posted 04 September 2019 - 12:40 PM

Mark,

 

You realize that all channels are shared with other users so you have no control over who may be on a channel where you have your repeater. I believe you will also find the store and forward repeaters to be much more of a PITA than a duplex unit. You need a radio at each location for the repeater to work as it receives the transmission storing it in its memory and then playing it back on the same channel. To better illustrate the use, a 20 second transmission from you takes another 20 seconds to repeat. A second unit on the same channel then adds it's 20 seconds to receive and send. A return message would make it through the repeaters in 40 seconds resulting in almost a 90 second delay between you sending and hearing the response. Like I  said, a real PITA for any real conversation.


Old and wise infers you were once young and stupid


#4 n4gix

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Posted 04 September 2019 - 12:54 PM

Okay, the huge elephant in your room is the license. It will cover you, your wife, your children, your brother(s), sister(s), brother(s) in law, sister(s) in law, uncles, aunts, cousins (both paternal and maternal), and Grandparents (both yours and your wife's). That's a lot of family!

I sometimes joke that it covers everyone except the "outlaws..."

But no it won't cover your church group or a Boy Scout Troop unless they are all relatives. There is also no such thing as a "group or organizational license". It is intended as a family radio service, although the FCC is remarkably generous in their definition of "family." smile.png

So called "store and forward" devices are not permitted by the rules.

#5 WRAK968

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Posted 04 September 2019 - 03:34 PM

Lot of information you need there sir, and so far Boxcar, N4GIX, and Zack have covered several parts of your requests. Here is my take on it:

1) GMRS covers your family only. I remember the local CERT wanting to use my GMRS repeater in the event of a major storm. I explained that in order for them to legally do this, each user would need their own license. I also explained that unlike ham radio where an emergency net has priority, GMRS has no stipulations, anyone can use it. For what you wish to use it for, I believe there are "Private" licenses, which are not on the GMRS frequencies, that you can apply for. This allows you to designate any person or group to transmit on your licensed frequency, and you would be responsible for any compliance issues that may come up. Likewise, you can use other radio services such as MURS without a license, however you cannot use a repeater and are restricted to 2 watts.

2) I've never been a fan of the micro mobile series. To me, the functionality does not meet the price. I can order a Kenwood TK880 for about $50 and have 25 watts output, plus I can program and save specific repeater splits into the radio with names and such. For about $25 more you can purchase the "H" model which will give you 45 watts. 880 series is smaller than most car stereos and fits almost anywhere. As for overheating, I am a strong believer in using TOT's or Time Out Timers. This prevents you from transmitting for long periods without giving the radio a chance to "rest and cool down." As for antenna's, I really don't have an opinion on them. Try to get something good from a brand you trust. 1/4 wave antennas if I recall dont need a ground plane and would be best if you plan to carry it around with you.

3) After reviewing the rules, I do not see a ban on store and forward devices, which fall under automatic control and is allowed by the FCC by licensed users. Store and forward MUST be on one of the repeater output channels and must be used in conjunction of a license. Store and forward is also restricted to low power. I may have overlooked something though so make sure to study the rules yourself and make your best judgement call.

4) Your repeater is only as good as your antenna. You should try to get your antenna up high so that you gt the best coverage you can. As for station grounding and lightning protection, a qualified electrician should be called in. I've seen some operators use the ground post for the AC mains power for protection however this isn't recommended as it gives lightning another path into the house. For proper protection, the best way to go would be to talk to an electrician about installing a lightning protected ground rod, which is longer than your mains ground rod. (Lightning protected ground rods can be anywhere from 16-100 feet depending on the soil type.) You would then need to install lightning arresters to your feedline, one near the antenna, one near the entrance to whatever structure you will store the radio in (house or shed.)

5) back to #2, TK880 is small and light weight.

6) See #2 and #5, TK880 is inexpensive but a workhorse. The big things to check are, Is the radio type accepted for GMRS (Part 95) you'll need to put the radios FCC ID into the FCC lookup and see what the FCC has certified it for. If its part 95 then your doing good. The other is the band. for GMRS you need something that covers from 460-470. TK880 has 3 UHF radios, Type 1 I believe covers 400-430, type two covers 450-490 and type three covers 480-520. You would need a type 2 radio 450-490 for GMRS use. Outside of that, its just features that YOU may want. Things like scan or radio ID or channel grouping.

7) GMRS was not exactly developed for emergency operations, though it can be used for such. It was designed to keep family members in touch with one another and to allow like minded licensed individuals to meet up with one another. Don't expect SHTF operations should all comms go down. For that, stick with ham radio where there is training and procedure to emcomms



#6 axorlov

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Posted 04 September 2019 - 07:14 PM

6) See #2 and #5, TK880 is inexpensive but a workhorse. The big things to check are, Is the radio type accepted for GMRS (Part 95) you'll need to put the radios FCC ID into the FCC lookup and see what the FCC has certified it for. If its part 95 then your doing good. The other is the band. for GMRS you need something that covers from 460-470. TK880 has 3 UHF radios, Type 1 I believe covers 400-430, type two covers 450-490 and type three covers 480-520. You would need a type 2 radio 450-490 for GMRS use. Outside of that, its just features that YOU may want. Things like scan or radio ID or channel grouping.

Speaking of TK-880, Type 1 is 450-490 MHz and certified as Part 95 radio. https://criticalradi...880h_ver2_k.pdf



#7 WRAK968

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Posted 05 September 2019 - 07:24 AM

Speaking of TK-880, Type 1 is 450-490 MHz and certified as Part 95 radio. https://criticalradi...880h_ver2_k.pdf

I stand corrected, Type 1 is 450-490 Type 2 is 485-512 and type 3 is the 400-430 (not sure why they went in that order) Thus you would need a TK880 type 1 radio.

Thanks for the correction Axorlov, good catch :)



#8 berkinet

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Posted 05 September 2019 - 08:08 AM

...
3) Repeater. I've considered using a simplex repeater (https://www.argentdata.com/catalog/product_info.php?cPath=27&products_id=98&osCsid=18AQ4OPGf1tOsN4yF2kZB2) specifically the ADS-SR1 Simplex Repeater....

There is some question about whether simplex repeaters are legal on GMRS. First, check out this thread from 2017. However, note that @commsprepper never provided any specific information (and, in fact, hasn't been active since shortly after he posted that comment.)

However, in spite of @jmoylan69's claim that nothing in Part95A prohibits simplex repeaters, there are two sections that could be read as disallowing such operations. Both have to do with One-way communications.

§ 95.1731 Permissible GMRS uses.
The operator of a GMRS station may use that station for two-way plain language voice communications with other GMRS stations and with FRS units concerning personal or business activities.
(a)Emergency communications. Any GMRS channel may be used for emergency communications or for traveler assistance. Operators of GMRS stations must, at all times and on all channels, give priority to emergency communications.(b)One-way communications. The operator of a GMRS station may use that station to transmit one-way communications:

(1) To call for help or transmit other emergency communications;(2) To provide warnings of hazardous road conditions to travelers; or,
(3) To make brief test transmissions.

and

§ 95.1733 Prohibited GMRS uses.
... ...

(b)GMRS stations must not be used for one-way communications other than those listed in § 95.1731( B). Initial transmissions to establish two-way communications and data transmissions listed in § 95.1731(d) are not considered to be one-way communications for the purposes of this section.

The argument can be made that transmissions of a simplex repeater constitute a series of one-way transmissions. Personally, I don't know if this is true or not and, frankly, I don't like the idea of simplex repeaters in the first place. However, I thought you'd want to know there is at least some question as to the permissibility of simplex repeaters on GMRS.

Personally, if I was in your position, I would look at building a portable repeater out of 2 decent quality HTs and a mobile duplexer. There are literally hundreds of pages around the web on how to do this. Here is a thread on radio reference.com that might be a good starting place.
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#9 BoxCar

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Posted 05 September 2019 - 12:12 PM

Simplex repeaters also fall within the following:

§95.1745   GMRS remote control.

Notwithstanding the prohibition in §95.345, GMRS repeater, base and fixed stations may be operated by remote control.

 

§95.1747   GMRS automatic control.

Notwithstanding the prohibition in §95.347, GMRS repeater stations may be operated by automatic control.

 

 

A Simplex repeater would operate the station with automatic control as it keys the transmit portion when the receive is complete. The control is seen as automatic in the same manner a duplex repeater keys a separate transmitter upon its receiver being activated. Remember, the simplex operation requires the repeater start at the beginning of the received transmission which cannot occur concurrently.


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#10 Guest_Mark Lewis_*

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Posted 05 September 2019 - 09:46 PM

To each and every one of you, MANY THANKS!! I appreciate the assistance and the information. You have been outstanding. 

 

1) radios. thanks for the addition resources. any others I should look into? any devices that allow for FRS, MURS, and GMRS? I have FRS/GMRS, MURS/GMRS but not all three.

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?

3) portability. is it even remotely possible to develop a truly portable mobile unit complete with power source and whip antenna for use in the field?

4) privacy codes. any instructions on how best to use these and call tones, etc?

5) easy. for now the people using this equipment will be my immediate family. however, if this setup isn't as a easy an keying a CB mike all bets are off. any suggestions?

 

Thanks for the help, insight, and advice.



#11 berkinet

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Posted 06 September 2019 - 12:56 AM

Simplex repeaters also fall within the following:

§95.1745   GMRS remote control.
Notwithstanding the prohibition in §95.345, GMRS repeater, base and fixed stations may be operated by remote control.
§95.1747   GMRS automatic control.
Notwithstanding the prohibition in §95.347, GMRS repeater stations may be operated by automatic control....

Note that not-disallowing something is not the same as allowing it. Just because simplex repeaters use automatic control technology, does not mean they are allowed. If that were the case, you could argue that a GMRS repeater could be used for any purpose as long as it was controlled automatically.

Everything we hear is an opinion, not a fact. Everything we see is a perspective, not the truth.

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#12 BoxCar

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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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#13 berkinet

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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.


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#14 quarterwave

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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. 


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#15 axorlov

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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.



#16 n4gix

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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

https://www.youtube....h?v=WZEAo_HkLv8

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.

https://www.retevis....ASABEgIJwvD_BwE


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#17 Ian

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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  



#18 n4gix

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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... ;)



#19 WRAK968

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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.



#20 berkinet

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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.

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