Home made/own GMRS Repeater

[RodrigoAGJ]

Hello!

I am new to the forum. My call sign is WRSL266 and I live in the city of Miami, FL. I really like the idea of being able to have direct communication with friends, groups and my family through a GMRS repeater.

How can I make my own functional, low-priced repeater to share with my community?

I appreciate all the information you can give me.

[Borage257]

Retevis has a turnkey solution for you. Their RT97 repeater is about $300-$500 depending on accessories.

With most things vhf/uhf height is more important than watts. If you can get the repeater (or its antenna) at about 50' above ground, you should be able to cover a few neighbor hoods. 

Here are a few threads in this forum on the unit.

https://forums.mygmrs.com/topic/4843-retevis-rt97-gmrs-repeater/#comment-47459

https://forums.mygmrs.com/topic/3755-rt97-real-world-output-power/

https://forums.mygmrs.com/topic/3353-retevis-rt-97-battery-size-recommendation/

https://forums.mygmrs.com/topic/2744-retivis-rt97-portable-repeater/

[SteveShannon]

22 minutes ago, RodrigoAGJ said:

Hello!

I am new to the forum. My call sign is WRSL266 and I live in the city of Miami, FL. I really like the idea of being able to have direct communication with friends, groups and my family through a GMRS repeater.

How can I make my own functional, low-priced repeater to share with my community?

I appreciate all the information you can give me.

Welcome, Rodrigo!

Without truly knowing what you consider “low-priced” I will say that the easiest path is probably to just buy a Retevis RT97, a good antenna, the best coax you can afford, and a mast to get the antenna up into the air.

[Borage257]

@SshannonThere is a post I can't seem to find anymore that I wanted to link here. A guy had a nice RT97 build running off solar up in the hills/mountains. Does that ring any bells?

[WRUQ758]

I have seen a few on Ebay that include controller & duplexer, usually Motorola mobiles converted. Just do your research on MyGMRS repeaters in your area and pick a repeater frequency pair that is least likely to cause interference with another. 

[gortex2]

As said the best bang for the buck is the RT97. Start with that and as you feel its used then upgrade. Buy a good feedline and decent antenna and it will work well. As said height is king. Get antenna as high as you can. Nice thing about the RT97 is it is waterproof so you can mount outside as long as you seal up the antenna connections. Putting it in an attic just below the antenna with a 6' feed line will work way better than 100' of LMR. 

@Borage257 There is another thread of a guy in Alaska who uses one on a pole with solar power. Think thats the one your looking for. 

[Borage257]

@gortex2I think it is, just having trouble finding it.

[PACNWComms]

My cheapest solution in the past for me was to use two Motorola CDM-1250 mobiles, and repeater interface "cable" from online auction sites. Using cheap magnet mount antennas and placing onto a desk was a cheap solution. These then ended up getting expensive after placing everything into a Pelican case, adding in Optima deep cycle marine batteries, Comprod antennas, high end tripod mounts for the antennas, and coax. 

[SteveShannon]

10 minutes ago, Borage257 said:

@SshannonThere is a post I can't seem to find anymore that I wanted to link here. A guy had a nice RT97 build running off solar up in the hills/mountains. Does that ring any bells?

Yes, I think it’ll be the gentleman in Alaska.  Wrrc399 or something like that.  I’ll look for it.

[gortex2]

@WRFP399 is the guy who has it. 

[SteveShannon]

Here’s one of the posts where WRFP399 describes his RT97S setup.  I’ve always been impressed by it:

 Steve

[OffRoaderX]

I've had 3 different repeaters over the last two years:

1. DIY 2 KG-1000Gs
2. Retevis RT97
3. Vertex VXR-7000

All using the same ~$120 Tram 1486 base antenna and 75 feet of LMR400 coax

• The two KG-1000Gs was the most expensive (~$875) and had the most power - but it was also the most unwieldy and issue-prone
• The RT97 was a much more compact package, and was the least expensive (~$400), but only output about 4-5watts after the duplexer and has a limited duty-cycle
• The  Vertex VXR-7000 (what I currently use) is by far the best solution. I paid $500 for mine (used), it puts out ~25 watts after the duplexer and it can be used 24/7 (100% duty cycle) - But because of its age its a bit of a pain to program/get set up.  

My recommendation, based on my experience, would be to try and get a good used commercial repeater (like the VXR-7000) OR an RT97.   Next month another company will be releasing a new GMRS repeater very similar to the RT97 but easier to configure -  but i'm not allowed to talk about that yet.. So you might want to wait and see if that one works better for your needs.

[SteveShannon]

40 minutes ago, OffRoaderX said:

Next month another company will be releasing a new GMRS repeater very similar to the RT97 but easier to configure

I sense a video from Notarubicon …

I look forward to seeing it. 

[MichaelLAX]

1970s Legacy Repeater 

[KAF6045]

Be advised that the /base/ RT97 does not have an ID system -- without it, the repeater is limited to "immediate family" using your callsign to ID (thereby IDing both themselves and the repeater).

Quote

§ 95.1751 GMRS station identification.

Each GMRS station must be identified by transmission of its FCC-assigned call sign at the end of transmissions and at periodic intervals during transmissions except as provided in paragraph (c) of this section. A unit number may be included after the call sign in the identification.

<SNIP>

 

(c) Any GMRS repeater station is not required to transmit station identification if:

(1) It retransmits only communications from GMRS stations operating under authority of the individual license under which it operates; and,

(2) The GMRS stations whose communications are retransmitted are properly identified in accordance with this section.

Note the "AND". Clause (1) "authority of the individual license" basically means "immediate family"; clause (2) thereby means users IDing with that license.

Quote

§ 95.1705 Individual licenses required; eligibility; who may operate; cooperative use.

A valid individual license is required to operate a GMRS station. To obtain an individual license, an applicant must be eligible and follow the applicable rules and procedures set forth in this subpart and in part 1 of this chapter, and must pay the required application and regulatory fees as set forth in part 1, subpart G of this chapter.

<SNIP>

(c) Individuals who may operate a GMRS station. This paragraph establishes who may operate a GMRS station under the authority of an individual license.

(1) Any individual who holds an individual license may operate his or her GMRS stations.

(2) Any individual who holds an individual license may allow his or her immediate family members to operate his or her GMRS station or stations. Immediate family members are the licensee's spouse, children, grandchildren, stepchildren, parents, grandparents, stepparents, brothers, sisters, aunts, uncles, nieces, nephews, and in-laws.

 

Clause (2)

[SteveShannon]

2 minutes ago, KAF6045 said:

Be advised that the /base/ RT97 does not have an ID system -- without it, the repeater is limited to "immediate family" using your callsign to ID (thereby IDing both themselves and the repeater).

Note the "AND". Clause (1) "authority of the individual license" basically means "immediate family"; clause (2) thereby means users IDing with that license.

Clause (2)

It's true that a repeater must be IDed if either or both of those two clauses is not true, but there's no technical requirement for an automatic ID system.  If the operator and users of the system identify it according to the rules that is sufficient.  Of course from a practical standpoint having an ID system is much more convenient.

[Fernleaf]

3 hours ago, OffRoaderX said:

I've had 3 different repeaters over the last two years:

1. DIY 2 KG-1000Gs
2. Retevis RT97
3. Vertex VXR-7000

All using the same ~$120 Tram 1486 base antenna and 75 feet of LMR400 coax

• The two KG-1000Gs was the most expensive (~$875) and had the most power - but it was also the most unwieldy and issue-prone
• The RT97 was a much more compact package, and was the least expensive (~$400), but only output about 4-5watts after the duplexer and has a limited duty-cycle
• The  Vertex VXR-7000 (what I currently use) is by far the best solution. I paid $500 for mine (used), it puts out ~25 watts after the duplexer and it can be used 24/7 (100% duty cycle) - But because of its age its a bit of a pain to program/get set up.  

My recommendation, based on my experience, would be to try and get a good used commercial repeater (like the VXR-7000) OR an RT97.   Next month another company will be releasing a new GMRS repeater very similar to the RT97 but easier to configure -  but i'm not allowed to talk about that yet.. So you might want to wait and see if that one works better for your needs.

So, is there an issue with operating a repeater that KAF6045 shows is a problem? I was talking with the head of my GMRS group to put up a repeater of my own. But he didn’t seem to think there were any problems doing so. It is operated under the license of the operator without any further legal ramifications as this individual indicated. 

[Fernleaf]

3 minutes ago, Sshannon said:

It's true that a repeater must be IDed if either or both of those two clauses is not true, but there's no technical requirement for an automatic ID system.  If the operator and users of the system identify it according to the rules that is sufficient.  Of course from a practical standpoint having an ID system is much more convenient.

How is this id done on a diy repeater, such as the linked KG-1000Gs?

[SteveShannon]

27 minutes ago, Fernleaf said:

How is this id done on a diy repeater, such as the linked KG-1000Gs?

It can be as simple as instructing anyone who uses your repeater to identify it whenever they identify their own stations, but of course that's subject to human frailty. For example, if I were using your repeater, I would say "This is WROM258 on repeater WRMM689."

Some (most) people purchase a device called an ID-o-matic, that sits between the two linked KG-1000G boxes and which automatically follows the rules for station identification.

The Retevis RT97 doesn't have an easy way to insert an ID-o-matic.  Its newer version, the RT97S has a port that should allow the use of the ID-o-matic, but I haven't done it so I cannot comment on whether it's easy or difficult.  The RT97S used to be much more expensive than the RT97, but lately they appear to be very close in price.  In fact, the shopping portal associated with this site had the RT97S for $100 off just the other day, but I think it was a limited time offer.

Edited to add: And there's at least one repeater owner who simply setup a Baofeng attached to his/her computer which transmits a call sign to the repeater every fifteen minutes:

Here are the FCC rules for GMRS identification:

§ 95.1751 GMRS station identification.

Each GMRS station must be identified by transmission of its FCC-assigned call sign at the end of transmissions and at periodic intervals during transmissions except as provided in paragraph (c) of this section. A unit number may be included after the call sign in the identification.

(a) The GMRS station call sign must be transmitted:

(1) Following a single transmission or a series of transmissions; and,

(2) After 15 minutes and at least once every 15 minutes thereafter during a series of transmissions lasting more than 15 minutes.

(b) The call sign must be transmitted using voice in the English language or international Morse code telegraphy using an audible tone.

(c) Any GMRS repeater station is not required to transmit station identification if:

(1) It retransmits only communications from GMRS stations operating under authority of the individual license under which it operates; and,

(2) The GMRS stations whose communications are retransmitted are properly identified in accordance with this section.

[OffRoaderX]

4 hours ago, Fernleaf said:

So, is there an issue with operating a repeater that KAF6045 shows is a problem? I was talking with the head of my GMRS group to put up a repeater of my own. But he didn’t seem to think there were any problems doing so. It is operated under the license of the operator without any further legal ramifications as this individual indicated. 

I put Kaf6045 on my "3rd-grade hall monitor block list" a long time ago so i dont know what he posted, but, It is important to know the rules.. It is also important to understand the risks and what happens in the real world..

The head of your GMRS group is correct, it is no more of an issue than rolling through a stop-sign is an issue, as the FCC, based on their published record of enforcement, does not care.

 

[Fernleaf]

Thank you. I always love your replies!!

I figured that the guy running our club probably knows the rules order well.  They’ve got linked repeaters covering nearly all of Georgia and parts of Tennessee and Alabama. Mine won’t be covering nearly that span!

 

 Those kind of posts just cause confusion to those of us newer to the radio world. Your clarity is appreciated. 

[Fernleaf]

21 hours ago, Sshannon said:

c) Any GMRS repeater station is not required to transmit station identification if:

(1) It retransmits only communications from GMRS stations operating under authority of the individual license under which it operates; and,

(2) The GMRS stations whose communications are retransmitted are properly identified in accordance with this section.

So essentially, being a private repeater (for now), all I need to be concerned with is just identifying when connecting and go on from there. Anyone answering will be doing the same as it’s all one license in the family.  
 

Additional expenses isn’t what I’m aiming for as it won’t be going public until I get more established in the area. That is future build. But the KG-1000G aren’t really built for that type of duty cycling. A true repeater system would be needed at that point. 
 

(I’d need a better paying job! )

[SteveShannon]

2 minutes ago, Fernleaf said:

So essentially, being a private repeater (for now), all I need to be concerned with is just identifying when connecting and go on from there. Anyone answering will be doing the same as it’s all one license in the family.  
 

Additional expenses isn’t what I’m aiming for as it won’t be going public until I get more established in the area. That is future build. But the KG-1000G aren’t really built for that type of duty cycling. A true repeater system would be needed at that point. 
 

(I’d need a better paying job! )

You’ve got it!  Best wishes getting that set up!

[Fernleaf]

Yea! Thank you!!

[SteveShannon]

1 minute ago, Fernleaf said:

Yea! Thank you!!

Honestly I wouldn’t even worry about the duty cycle.  I’m sure in some places repeaters get a lot of use, but most of the ones I hear in Montana are seldom transmitting more than twenty minutes continuously.  Run it until it needs to be replaced, then you’ll have a pretty good idea.