125 replies to this topic

[Lscott]

Good post... Nice read to let new-comers know what the reality is.

 

As far as "mobile repeaters" go... to do it right, its much more expensive and difficult than a fixed-station repeater, with nowhere near the performance advantage.  I built a portable repeater system for a government emergency response team.  It cost  a bit over $16,500.

 

The antenna alone was a massive project.  It was on a 10' tall tripod (mast mount centered half way up) with a 30' fixed mast and a 30' crank extension, for a total of 65' of elevation.  The equipment and batteries were extremely heavy and had to be installed in vented enclosures to keep them dry and cool.  The repeater had to be trucked to a location and dropped at a high-point.  Setting up the portable tower took a huge amount of labor and real estate to get it stood up and staked out so it was straight and wouldn't fall over in 20-30 mph winds.

 

And unless you have a babysitter, you need self-contained GPS tracking and local alarm on the transceiver in the event that some knucklehead finds your repeater and decides to leave with it.

That all depends. I have a Ham buddy who built a special event repeater, for local marathons and bike runs, really cheap with some used radios and a good power amp. The way it was done is using cross-band repeating so the expensive cavity filters get ditched. Most Ham HT’s can be programmed to do split band operation. You RX on one frequency on one band, say VHF, and TX on another, UHF, when you press the PTT button. For Ham radio this usually ends up being the 2 meter and 70 cm bands. On the repeater side a simple diplexer is enough to work the VHF and UHF radios into and can be had for $50 to $75 new.

 

Then he takes advantage of the local high rise buildings. Through his contacts he has access to the roof tops. No need for an expensive tower and feed line. When you’re on top of a 10 to 15+ story building you get some decent coverage. Since the repeater can be located close to the temporary antenna you don’t need expensive feed line. And what you do use is fairly short thus keeping the losses down and thus the TX’er power required.

 

Granted his conditions are not the general case but if one looks around and takes advantage of the local resources you can save a huge amount of money and effort. 
 

However if one wants to build an in-band repeater, then yes it gets more complicated and likely expensive as you pointed out.

[marcspaz]

Not disagreeing there, but there are serious limits to crossband repeaters.  They do have their place though.  I have a complete X-Band repeater system that will work with any two bands, covering 10m, 6m, 2m and 70cm.  Including antennas, a battery, diplexer, solar charger and the radio... it was about $700 for support of 50% duty cycle, 24x7.  It is almost exclusively used for me, personally... not others.

 

The model you discussed is known as ITDR, or Indirect Transmit / Direct Receive. An example of some problems you will experience with these types of solutions are limiting the users to only people you make aware of it (compared to known offsets for same-band), many times the repeater antenna is too close to the ground and other obstructions for any significant increase in coverage, and your receive is significantly hampered by the fact that you are listing direct on an HT.

 

My gear supports ITDR and ITIR (Indirect Transmit / Indirect Receive).  ITIR helps with both the ability to transmit and receive, but now significantly restricts who can use the repeater, normally being used/usable by a single operator to extend their TX/RX range.

 

In general, they can be a great individual solution for Hams and (if planned in advance) be a marginal solution for a group of Hams with the correct / compatible gear, but not ideal for a true repeater service and definitely not legal in GMRS.

[Lscott]

Not disagreeing there, but there are serious limits to crossband repeaters.  They do have their place though.  I have a complete X-Band repeater system that will work with any two bands, covering 10m, 6m, 2m and 70cm.  Including antennas, a battery, diplexer, solar charger and the radio... it was about $700 for support of 50% duty cycle, 24x7.  It is almost exclusively used for me, personally... not others.

 

The model you discussed is known as ITDR, or Indirect Transmit / Direct Receive. An example of some problems you will experience with these types of solutions are limiting the users to only people you make aware of it (compared to known offsets for same-band), many times the repeater antenna is too close to the ground and other obstructions for any significant increase in coverage, and your receive is significantly hampered by the fact that you are listing direct on an HT.

 

My gear supports ITDR and ITIR (Indirect Transmit / Indirect Receive).  ITIR helps with both the ability to transmit and receive, but now significantly restricts who can use the repeater, normally being used/usable by a single operator to extend their TX/RX range.

 

In general, they can be a great individual solution for Hams and (if planned in advance) be a marginal solution for a group of Hams with the correct / compatible gear, but not ideal for a true repeater service and definitely not legal in GMRS.

I think his was a full cross band, duplex, design. The two radios are cross connected. He did his initial testing with the antenna on his tower.

 

He is also the main radio tech for a local city’s transportation department. He done some tower climbing and repeater installs. Many of his comments are similar to yours.

The one I remember most is a story where another tech went out to check the repeater equipment in the shack at the tower base. Opened the door only to discover a huge hornets nest inside. By the time help arrived he was passed out on the ground from all the stings. Luckily he survived.

[marcspaz]

I think his was a full cross band, duplex, design. The two radios are cross connected. He did his initial testing with the antenna on his tower.

He is also the main radio tech for a local city’s transportation department. He done some tower climbing and repeater installs. Many of his comments are similar to yours.
The one I remember most is a story where another tech went out to check the repeater equipment in the shack at the tower base. Opened the door only to discover a huge hornets nest inside. By the time help arrived he was passed out on the ground from all the stings. Luckily he survived.

Wow! That is terrible. Glad to hear h made it. The worst I came across was a Copperhead infested shack. Fortunately there was plenty of evidence outside, before we even opened the door, so we were able to get past control out before we did.

I have been thinking about building a self-contained repeater system that you can connect to any two radio and turn them into a repeater. Its pretty easy to design. I did one back in the mid-80's. I'm just so busy, I dont have time for it.

[Lscott]

I’ve looked at those cheap repeater controllers. Those are the ones you connect two radios together using the mic/speaker jacks and key the other radio using VOX. The main complaint I have with using one for a quick throw together repeater is the lack of an ID function. I have looked at the “ID- O-Matic” which has it but you need a COR it seems to make the thing work, which of course an modified radio doesn’t provide. So that brought me back to the first option about hacking the hardware to add an ID function. The cheap controllers without the ID could be used in two cases. The first is a half-duplexer repeater, which has the limitations you pointed out previously, and used exclusively by the licensed user. The second is with GMRS, but only if qualified family members use it exclusively since everybody ID’s using the same call sign. All other cases the repeater needs to self ID. The strange thing is the one GMRS repeater by me, which I have the owners permission to use, along with a few friends, I have NEVER heard it ID yet. How the owner is getting away with it beats me other than the FCC doesn’t want to bother with it. It doesn’t get much use so unless you know it’s there you wouldn’t notice.

[marcspaz]

...I have NEVER heard it ID yet. How the owner is getting away with it beats me other than the FCC doesn’t want to bother with it. ...

Per 47 C.F.R, Part 95 Subpart E, §95.1751 ( c ) states that the repeater doesn't need to ID itself if... (2) The GMRS stations whose communications are retransmitted are properly identified in accordance with this section.

So, even if the license holder is not using the machine, if people that are using it properly ID, the the repeater is considered in compliance with ID requirements.

[Lscott]

Per 47 C.F.R, Part 95 Subpart E, §95.1751 ( c ) states that the repeater doesn't need to ID itself if... (2) The GMRS stations whose communications are retransmitted are properly identified in accordance with this section.

So, even if the license holder is not using the machine, if people that are using it properly ID, the the repeater is considered in compliance with ID requirements.

That doesn’t make any sense to me. The point of ID’ing is so the owner of the repeater can be contacted in case of a problem. I don’t own the repeater I mentioned and I’m sure the FCC won’t be knocking on my door, nor anyone else using it with their own call sign, if there are issues. Without a proper ID how would they know who really is in control of it? It’s a lot less work to get the call sign of the owner from the on-air self ID, look them up in the FCC database then contact them directly. The other choice is having the FCC pull the plug then wait around to see who shows up to check the system out wondering why their repeater quit. If nobody shows up, the repeater is off the air problem solved anyway. Might even pack it up and take it with them on the way out the door. If their nice they could leave a nasty note taped to the empty rack.

[marcspaz]

That doesn’t make any sense to me. The point of ID’ing is so the owner of the repeater can be contacted in case of a problem. I don’t own the repeater I mentioned and I’m sure the FCC won’t be knocking on my door, nor anyone else using it with their own call sign, if there are issues. Without a proper ID how would they know who really is in control of it? It’s a lot less work to get the call sign of the owner from the on-air self ID, look them up in the FCC database then contact them directly. The other choice is having the FCC pull the plug then wait around to see who shows up to check the system out wondering why their repeater quit. If nobody shows up, the repeater is off the air problem solved anyway. Might even pack it up and take it with them on the way out the door. If their nice they could leave a nasty note taped to the empty rack.

 

Repeater sites are (or at least should be) registered with the FCC.  In order to put up a tower, there has to be permits issued, an environmental impact evaluation, an FAA Risk/Impact evaluation and a RF exposure evaluation, determining RF exposure health risk to people/animals in the area... and all submitted to the FCC as proof that you are in compliance with all applicable laws.  Plus the FCC regularly does site inspections. 

 

These systems don't cover a tremendous amount of real-estate and there are not many of them in many areas.  If a machine starts doing something stupid or is non-compliant, I promise you, unless the owner has completely ignored every single law and requirement, they know who owns what machine and where to find both the machine and its owner.

[Lscott]

Repeater sites are (or at least should be) registered with the FCC.  In order to put up a tower, there has to be permits issued, an environmental impact evaluation, an FAA Risk/Impact evaluation and a RF exposure evaluation, determining RF exposure health risk to people/animals in the area... and all submitted to the FCC as proof that you are in compliance with all applicable laws.  Plus the FCC regularly does site inspections. 

 

These systems don't cover a tremendous amount of real-estate and there are not many of them in many areas.  If a machine starts doing something stupid or is non-compliant, I promise you, unless the owner has completely ignored every single law and requirement, they know who owns what machine and where to find both the machine and its owner.

What you said is true I’m sure for commercial systems, public safety etc. I don’t recall seeing anything in the FCC rules requiring a GMRS repeater to be registered with the FCC. Neither are Ham repeaters, but you do work through a local frequency coordination body which is not part of the FCC. The only requirement is each station must ID, so as long as only qualifying family members use the machine it doesn’t need to self ID. Each qualifying family member when they ID satisfies the requirements. However if non qualifying family members use it then it’s impossible to determine who is the owner unless it self ID’s.

 

This was EXACTLY the problem I had trying to identify the local repeater I’m currently using. No self ID, nothing shows up of any use when doing an FCC GEO search on the exact frequency over a limited range of 50 miles. I finally tried contacting the owner because it was listed on this site’s repeater database, by shear luck and I still wasn’t really sure. But even then the info was wrong because the owner died and the listing wasn’t updated for a few years. Months went by and no response to my emails, unknown at the time they were going to a dead guy’s account. Then when it was updated everything got worked out really quick. If it had ID’ed with the current owners call sign a simple lookup of that in the FCC license database would have given me the contact info I needed and saved me a lot of screwing around.

[marcspaz]

What I wrote is all required by law to put up an antenna tower.  It doesn't matter who owns it or what service/band its on.  Even if someone puts up a Rohn 45 in their backyard, all of the things I wrote are required by law and FCC rules.  If private owners choose not to, they are in violation of federal law.

 

If someone has a private use repeater at their house or business and its mounted on a building not more than 10' high from from top of the roof, then I suppose it would not go through any of that... but it wouldn't be much of a repeater, either.  I guess it would be okay for their HT's while around the house/neighborhood, but that would be about it.

 

As far as finding a station (and owner) that does ID, that is actually really easy.  There are free, online RF detection centers all over the globe.  Especially here in the US.  Once you have the address, you can lookup the land owner and you're done. 

 

I have a local UHF broadband repeater that started causing issues around here.  I was able to find the repeater in just about 15/20 minutes. It happened to be owned by the local FD, so it was easy to find out who to talk to.

[berkinet]

...There are free, online RF detection centers all over the globe.  Especially here in the US....

 

Could you note a couple.

[marcspaz]

Could you note a couple.

Sure... I have some saved on my PC. When I get home, I'll share a couple.

I know Hackaday provides direction finding with a bunch of online SDR's. I don't remember the others.

Edit- I just remembered... WebSDR has a whole list of services. Just pick a station that covers the frequency you want to use and be sure direction finding is one of the services.

[Lscott]

What I wrote is all required by law to put up an antenna tower.  It doesn't matter who owns it or what service/band its on.  Even if someone puts up a Rohn 45 in their backyard, all of the things I wrote are required by law and FCC rules.  If private owners choose not to, they are in violation of federal law.

 

If someone has a private use repeater at their house or business and its mounted on a building not more than 10' high from from top of the roof, then I suppose it would not go through any of that... but it wouldn't be much of a repeater, either.  I guess it would be okay for their HT's while around the house/neighborhood, but that would be about it.

 

As far as finding a station (and owner) that does ID, that is actually really easy.  There are free, online RF detection centers all over the globe.  Especially here in the US.  Once you have the address, you can lookup the land owner and you're done. 

 

I have a local UHF broadband repeater that started causing issues around here.  I was able to find the repeater in just about 15/20 minutes. It happened to be owned by the local FD, so it was easy to find out who to talk to.

The repeater I was trying to locate turns out it’s on the top of a building that’s listed as the roof top at 206 feet above ground level. So per your points it wouldn’t have been required to be registered with the FCC.

 

There is also a Ham repeater on the top of what is now GM’s headquarters. That’s only 14 to 15 miles line of sight from my house.

 

http://www.gmarc.org...-compressed.jpg

 

There is also another Ham repeater just a mile or so from the GMRS one on top of another building at 300+ feet. Both of which are just under 5 miles to the west of my location.

 

Both Ham repeaters do self ID.

 

Since the above are not on a tower, and the antennas are mounted close to the roof top there is no legal requirement they be registered with the FCC? 

 

I was not aware of any FCC requirement to register if you’re on a tower however. That’s new one for me. Thanks for educating me on that.
 

I also monitor the security frequencies from two local malls. It was rather interesting when the police protesters showed up by the one in Sterling Heights a few weeks back. Both use repeaters. Nether one self ID’s that I can tell from several years of monitoring them. Both are listed in a well known on line scanner database.

https://www.radioreference.com

 

In that one of the two shows the call sign for the repeater. There is nothing listed for the other one. Again doing an FCC GEO search on either the input or output frequencies yielded nothing that makes sense. A search of just the frequencies used for the city, where I’m guessing the repeater is located at the mall, didn’t yield anything useful either. How would one use freely available sources to track down the owner, and the call sign, of the non ID’ing repeater?

So for the two malls how can they operate with out either the repeater nor the hand held radios used ID? Is there a specific FCC rule that allows this or are they in violation?

[kb2ztx]

We are getting off topic here.

 

GMRS does not have to ID. Period. Per rules. None of mine ID. Commercial Part 90 Repeaters must ID per rules. Alot of Part 90 repeaters ID with no PL/DPL tone so if you have a scanner with PL/DPL enabled you will never hear the ID.

[Lscott]

We are getting off topic here.

 

GMRS does not have to ID. Period. Per rules. None of mine ID. Commercial Part 90 Repeaters must ID per rules. Alot of Part 90 repeaters ID with no PL/DPL tone so if you have a scanner with PL/DPL enabled you will never hear the ID.

GMRS doesn’t have to ID? What section is that in the rules?

 

When I’m scanning I have all the tone decoding turned off so I don’t miss anything. I’ve never had it on.  Still don’t hear any ID. I do occasionally hear the MDC burst from Motorola radios, but not all of them.

This really isn’t just an academic issue. There have been enough posts I’ve read where users have the same problem, trying to figure out who to contact for permission to use a repeater. The typical answer is listen for the ID, dah, what if there isn’t one? Without something to work with the problem isn’t easy. For anybody thinking about putting one up some thought needs to be put into the decision based on who is going to use it and how is anybody monitoring it on the air going to figure out who to contact.

 

Not everyone has access to expensive for pay database services. Not every GMRS, for that matter Ham, repeater is listed in commonly available on line databases. That’s been another complaint here as well. The database on this site has repeaters listed that no longer exist, repeaters that exist but the owners choose not to list it, I know of a few of those too where a buddy lives, and just plain wrong info on some that do exist, like the one I tried tracking down.

 

When somebody asks about putting up a repeater it isn’t just about do you need one. There is the engineering aspect and the regulatory requirements too. The repeater doesn’t live in a vacuum, it has to coexist with other stations and users so going a step beyond what the letter of the rules require could be well worth the effort. All are important IMHO when asking about advise.

[quarterwave]

GMRS repeaters do not have to ID. The users of the repeater must ID when they use it. 

 

When I first became licensed, about 25 years ago, you had to designate on the application IF you were going to have a repeater, how many mobiles, how many portables.... also you had to designate which pair you were using for the repeater, your LAT/LON and calculate your ERP. You don't have to do any of that now. If the FCC needed repeaters to be "registered" they would still require that. 

 

Tower wise, mine is beside a barn on a hill, it's about 35 feet with a 18 foot ASP fiberglass stick on top. There was never a requirement for a site registration because we are under 200' tower height, and not in a flight path. There are TV antenna towers at 60 feet around here...so no issue there. 

[Lscott]

GMRS repeaters do not have to ID. The users of the repeater must ID when they use it. 

 

Unfortunately that's not exactly what the rules really say.

 

https://www.law.corn...text/47/95.1751

 

Reading the above we have the following:

 

There are two usage cases that are being confused. One where everyone using the repeater is operating under the authority of the repeater owner (FCC licensee), and the other is when "others" with their own FCC issued call sign use it, either granted permission by the owner or the repeater is listed as "open" for public use.

 

If the users are all operating under the authority of the repeater owner then yes it doesn't need to self ID. 95.1751 (c1) and (c2) This is the only exception to the repeater ID requirements. This makes sense since everyone operating under the authority of the repeater owner all are using the same call sign. So when they ID the repeater is also properly ID.

 

However if you read this critically the repeater MUST self ID, as stated in the rules for any GMRS station, if it is being used by anyone else other than stations operating under the authority of the repeater owner. This is the part I think everyone misses. Just because the FCC hasn't busted anyone for this doesn't imply a rule violation is not occurring. Same thing with Part 90 radios being used on GMRS, some in fact have been used for building GMRS repeaters!

 

In the usage case I had originally mentioned the repeater owner is allowing other licensees to use it and it doesn't self ID with its owners call sign, ever, when in use or otherwise.

 

I've never asserted that GMRS repeaters must ID if they are not in use. It would be nice if they did. That helped me very late last night, 2AM to 3AM, when tropospheric ducting was going on. A distance GMRS repeater, I caught only part of its CW ID before it faded out, operating on the same repeater channel as the one I use locally, the one that never ID's. No the DX repeater wasn't activity being used so without it automatically self ID'ing I wouldn't have known it was there.

[quarterwave]

That's fine. One needs to understand the differences of FB2, FB4 and FB6 to really see the light here. 

 

The point it is...a repeater does not run itself, so a licensee and possibly the one that owns it will be the one using it. The transmitter is not required to be located on the license. The real way to track it...if they did was through the call sign of the user...and I don't know any owners that wouldn't, at some point use their own repeaters. In the Ham service it's always been the thing to have a IDer on the machine...in commercial I saw very few. I can say I have seen a 15 mile circle where a licensee in GMRS had 3 repeaters on the same frequencies, each with a different input PL and none of them ID. If they did they would put out the same ID. 

 

It's not just a cut and dry deal...

[Tsavorite75]

Lots of great repeater information on here. As for myself I will stick to the ones that are open for now and then way later down the road I will ask to use someones repeater possibly. As for building one out from what I see on here that can get expensive which I would have no clue how to at this time . Wealth of information on here. I look forward to eventually having a repeater later down the road. For now this is all new for me and is great.

[danielh3]

Why does every new license holder want to setup a repeater? I would like to shed a little light on some of the important things to consider if you recently got your GMRS license and now want your own repeater.

 

First thing to consider, are there any open well placed repeaters in your area that you are able to use? I can assure you most repeater owners want people to use there repeater. Owning several repeaters I can assure you all are welcome and encouraged to use my machines.

 

Do you have access to a location to host your repeater? If your answer is your garage roof you should reconsider. Your garage roof will give you about the same coverage as simplex. Unless you’re on top of a mountain and all your users are at the bottom you will never be happy with this setup.

 

GMRS is not as popular as one would like to think, unless your repeater covers 20 miles or more you may find you only have 1 or 2 users in the area. Unless you already have a group of friends together you may want to consider this before spending money on a decent well positioned site to install your repeater.

 

So you found a nice high site and the price is right, all you need to do is get the repeater installed, sounds simple right? Some thigs to consider first and foremost are the costs because they can add up quickly. Are you on a commercial tower that requires a license and bonded climber? If so this could be by far your largest expense depending on your area. I have spent $600 to $1200 on a climber; I have had quotes as high as $2500 depending on the amount of work and heights involved.  Keep in mind commercial sites require certified mounts, hard line cable, cable clamps, engineered grounding solutions and commercial grade antennas. No tower owner is going to let you install a comet antenna and 200’ of braided shield coax.

 

This brings me to my next point, the antenna. Because of the costs involved with climbers you will want to expend your budget on the antenna. Remember a $2000 repeater on a $200 antenna is going to work about as good as a $200 repeater.  Whereas a $200 repeater on a $2000 antenna is going to work like a $2000 repeater. On my first repeater I was gifted use of a 150’ tower, I installed a DB-420 on the top and 160’ of 7/8 hardline. Total cost of equipment for the antenna install was $2500, with the climbers labor coming in at an additional $800. This left me with enough to purchase an old Motorola R100 repeater running at 25W. To my surprise it had 30 miles of coverage, all due to the cash spent on the antenna and waiting for a decent spot.

 

Things happen, more so if you have an antenna 200’ in the air with a conductive cable connected to sensitive electronics. Antenna issues, feedline issues, repeater issues all cost money and I promise at some point you will have issues that need repair and require your money!

 

It is my opinion that the GMRS community does not need another 2 to 5 miles repeater as it just becomes background noise. What use is a public listed repeater if somebody in a mobile can’t use it 5 miles away while moving or the portable coverage is only a mile? If after reading this you are still going to build a repeater for your garage more power to you, just don’t expect 20 people to show up if it only reaches a mile.

 

As the owner of several GMRS and Commercial repeaters I can attest to the amount of money and effort go into my repeaters. I have only touched on the basics, if you add in any kind of testing services, duplexer tuning, addition of a combiner channel to an existing tower system, RF engineering, rent and insurance your costs can sky rocket. The best advice I can give any new licensee is to try and use the available systems in the area. Take the time to learn a little about what you’re doing and to assess the usability of the service before investing in a repeater for the sole reason of saying you own one.

What are the options for someone who lives in an area where there are no repeaters?