Huge repeater

[deputycrawford]

     A good friend of mine has put up a GMRS repeater in my area that is over 400 feet in the air.  He is using a borrowed digital repeater for the moment but will re crystal his big 100 watter for use soon.  He just got ahold of 7/8 hard line and a 16 bay folded dipole that he believes is 10 or 12 db gain. He will turn it down to keep the repeater safe, and it is on top of a building so the hard line is super short.  He has his ham, commercial, and GMRS licenses, and used to work for a radio service so he can get a lot of stuff super cheap or free.  He has a 40 mile foot print now and hopes to get it back to almost 60 miles like his commercial machine used to do it the same exact location.  If he runs the repeater at 75 or 80 watts and has about 50 at the antenna is he legal?  I hope so.  Just questions.  Should be huge by the end of the month.

 

Jerry

[PastorGary]

Jerry - GMRS equipment - including repeaters - can only have a maxmum RF power at the radio connector of 50 watts.  Regulations do NOT limit antenna gain for a higher ERP, but the power regulation is cast in stone. If he has a GMRs license, he should already be aware of the regulation -

 

47CFR95.135   Maximum authorized transmitting power.

 

(a) No station may transmit with more than 50 watts output power.

[deputycrawford]

Ok, thanks.  He has been reading up about the GMRS repeater stuff so I'm sure he is going to set it at the 50 watts.  It should still be a big booming repeater for the area.  A guy is getting into it already from Clyde, Ohio so when it gets stronger it should be full quieting almost everywhere.  He is moving the transmit stick up another 20 feet so it should be almost 430 feet.  That is great for this flat area.

 

Jerry

[PastorGary]

Thanks Jerry - We wouldn't want your colleague to get a visit from 'the men in black' for operating outside the power requirements...  

[deputycrawford]

     Update, we changed to the 9.2 DB gain antenna, and put "cans" in the transmit.  I know that's not a good term but you know what I mean.  This thing sounds sooo good.  A friend can also get into it from his portable a couple miles into the next county, and the repeater is located in the center of my county.  I think Tim said there are around 8 or 9 new GMRS licensees in our area that are starting to use the repeater.  Two of them, my brother-in-law and my son, are mostly through the ham tech book and starting practice tests on QRZ.COM.  We have started something here and may have two new hams soon from it.  It feels good to make a difference.  One guy gets into the repeater from about 55 miles away on a portable that lives on a hill.  Very cool. Just thought I would let everyone know.

 

Jerry

[PastorGary]

Thanks, Jerry - Sounds as if that system might have more usable range than the local Sheriff's system... but, that is common with many GMRS systems.

 

[Logan5]

Yep, sounds like an IDEAL installation, 50watts into short hardline on high gain antenna at altitude. Super range and building penetration. I hope you guys list it here. does it have a travel tone?  

[Guest spd641]

Jerry,

I hope he enjoys the new repeater,it sounds like he has it nailed down real well.I have a small repeater using minimal power and a Station Master antenna about 9db with only LMR400 which I had on hand.I could not believe the range 60 miles on a mobile and 40 miles on a hand held from the last range test I did a few weeks ago...William

[PastorGary]

William - Is your coverage on I-65 south of Cullman better now than last year?

[Guest spd641]

William - Is your coverage on I-65 south of Cullman better now than last year?

P-G,

It is different in several directions due to terrain with exceptions to the mountains,in the I-65 cooridor which seems most repeaters have trouble getting into including our amateur repeater locater just 14 miles off the 284 exit where we met,it seems those valleys are somewhat of a RF dead zone unless you are talking to a repeater toward Cullman or Birmingham and back to the west in Walker county.....William

[PastorGary]

Thanks William - on our next trip through the area we'll have less antenna on that vehicle, but we'll give it a try anyway.  I might be able to change things at my end by then - it's still a few months off.... I'll see what I can come up with for mobile gain.

[deputycrawford]

     Thanks guys for the input.  Yes the repeater is 425 FT in the air with a 9.2 DB transmit and a 10 DB gain Channel master in the receive, as well as the 100 FT 7/8 hard line at both ends.  It's booming big time for our area.  PG I believe it does work better than our old 460.475 Sheriff system used to.  I had 6 or 7 users on it at the same time a day or two ago. We did well with short transmissions and everybody got a turn.  Things are looking good in our area. 

 

     We have bad weather possibly coming into our area tonight and tomorrow so I have three people ready to take the mike near a computer to give us weather updates if another is away.  I will be on12 hr patrols for the next two days so I will try to spot, or help as I can.  We are having a TON of fun with this radio service. 

 

Jerry

[deputycrawford]

     Tim, the repeater owner, actually got into the repeater From Cedar Point on his portable, and I had a conversation with him for quite awhile from the parking lot from his mobile.  Cool beans I tell you.  He has a site he can get for free that is 400 Ft in Sandusky that will cover Cedar Point and much more.  He has the repeater equipment but has to get it up yet.  Maybe in a couple months we will have awesome Cedar Point coverage with a travel tone.  Things are looking up.

 

     Oh, by the way, I got a new license on the way for another new user, and found 4 more Baofeng 888 radios, correct for part 95, on order for $14,56 each.  Things are happening in Ohio. LOL

 

Jerry

[WQPE714]

meh just do it, not like the FCC ever cares or wants to do anything. At least the community will get better repeater service range.Theres even one on a mountian in my area doing 300 watts. It's all fine.

[quarterwave]

meh just do it, not like the FCC ever cares or wants to do anything. At least the community will get better repeater service range.Theres even one on a mountian in my area doing 300 watts. It's all fine.

 

No, I'm afraid it's not "all fine". Follow the rules. I have read a couple of your posts, are you here to participate or instigate? Sounds very negative to me. I think I can speak for all members in saying we welcome participants....not problems. Let's don't be antagonistic...or maybe this isn't the site for you.

 

And furthermore...a 300 watt repeater has no better usable range than a 50 watt repeater if the receive isn't enhanced. 4 watts from a portable still only goes so far to reach a repeater....300 watts is just "broadcasting" and is likely hurting the receive side more unless using high dollar cans, pre filters/selectors, etc.

 

Moderator - if I am being too forward with our new member here, please delete. Just calling it as I see it, and don't want something getting out of hand.  

[PastorGary]

Quarterwave - everything is cool at your end and we sent you a PM regarding the situation to which you have responded to.

 

We will only say this one more time in the open before the staff here takes punitive action:

 

We DO NOT want to see any posted suggestions regarding BLATANT** unlawful operation - such as over power being an "OK - who cares" situation, Ham equipmment being used on GMRS frequencies and so on.  Any further postings of this type will trigger an automatic staff response which may decrease our membership by one, as well as being removed from the main website registration. The suggestions made by the individual in question may also potentially stir the interest of the Commission because the Commission IP address shows up occasionally as a guest here and the call sign of the person is clearly visible. Need we say more?

 

 

The MyGMRS staff

________________________________________________________________________

 

[** ref: the Part 90 equipment in Part 95 service is not a blatant issue as of this time and is still on the table for discussions as usual.]

[Guest spd641]

May I also add this is a family oriented forum and we do not condone certain types of language or "by words" that may be seen by children or adults that may find it offensive...William

[deputycrawford]

     Thanks for the words to keep the post going the right way.  I read back through it and want to answer a couple questions.  We do not have a travel tone on the repeaters yet.  Tim has to get his Motorola MSR2000 repeater up there so he can use his good controller.  When he use his controller remotely he will add a travel tone to it.  We have both of them registered on this site.  He might get to the Paulding site first, so he will get that one running first, but he hopes to get the Sandusky, Ohio site up soon and put a travel tone on it.  It will be an open repeater for all to use.

 

     I will read back through this thread again but I might have mentioned Tim retired from a two way mobile company as their main tech.  He still helps them out a bit so the owner has allowed him to put up the GMRS repeaters at commercial sites with most being at the 400 Ft area.  All on commercial towers, or tall buildings, and all 7/8 hard line and Super Station Masters already in line.  The two way radio company owner has allowed all sites for free, including the use of the antennas etc., and Tim helps him out by doing a repair, or new install, for free once in awhile.

 

Jerry

[PastorGary]

Jerry - Thanks for the updates... always interesting to see how members and colleagues are making the service better for many persons.

[deputycrawford]

Tim put his MSR2000 repeater back together with a 1225 radio in line.  He set it at 6 watts, added a 10dB intenuator in line to drop the power to 1/4 watt to excite the amp.  Then set the amp at 50 watts and programmed for the 550 and tested it until it was ready to put up. HE THEN GAVE IT TO ME.  We swapped it out with the Icom repeater and let it rip.  We went from 25 watts out to 50 watts out.  WE are going up Wednesday to do some antenna work and put the Icom back in line wit the 575 in it. They will both be over the 400 ft mark at the same site.  Kewl I tell ya. Always a work in progress.

 

Jerry

[Tim]

yes Jerry's black swamp 550 is working great and we put the black swamp 575 system on the air only to find that we have unlicesed users on simplex 3 blocks from the system and once they get reprogrammed we will start using it, we only did this to be nice because of who it is and I'll let Jerry tell you about that LOL

[jimenezl]

Hello all, Did I read correctly, that the baofeng 888 is part 95 compliant?

Thanks,

Louis

WQUS816

[zap]

Power doesn't always translate to distance. 

 

A couple of things to remember, the biggest attenuator to FM communications is the ground. Path loss on a 50W GMRS radio, a commercial grade receiver, and 1/4 wave antennas is nearly 6000 miles. However, this number goes south quickly when you start talking about punching through urban environments, trees, hills, etc. With GMRS, you're pretty much guaranteed a successful transmission if there is unobstructed line of sight. More power means greater risk for desensing the receiver (what good does it do to have a repeater that can be heard for 100 miles but only talked to for 35?) which means adding extra filters, more antenna separation, etc. 

 

The 675 and 700 repeaters in Lubbock. The 675 repeater is on the tallest building for 120 miles. The antenna is 360 feet off the ground. It's running 50W at the transmitter and 40W at the antenna (which is a DB420).That's 477W ERP. It fizzles out about mile marker 41 on I27 (it's located at marker 4 roughly). The 700 repeater is a good 70 feet below it running 32W (23W at the DB420)...it fizzles out around mile marker 38. The two sites are 1000 feet away from one another. 70 feet is what mainly makes up that extra 3 miles.

 

95% of the time, you'll never notice the difference between a repeater running 200W or one running 25W if it's in a good location.

[mel]

Did I read correctly, that the baofeng 888 is part 95 compliant?

 

I read that too...but alas a search on https://apps.fcc.gov/oetcf/eas/reports/GenericSearch.cfm  =

There are no applications on file that match the search criteria specified: 

Grantee Code: ZP5 Rule Part Exact Match: Selected First Rule Part: 95 

 

Same with 95a. So the search for the cheap, legal, full power gmrs HT continues...

[quarterwave]

Power doesn't always translate to distance. 

 

A couple of things to remember, the biggest attenuator to FM communications is the ground. Path loss on a 50W GMRS radio, a commercial grade receiver, and 1/4 wave antennas is nearly 6000 miles. However, this number goes south quickly when you start talking about punching through urban environments, trees, hills, etc. With GMRS, you're pretty much guaranteed a successful transmission if there is unobstructed line of sight. More power means greater risk for desensing the receiver (what good does it do to have a repeater that can be heard for 100 miles but only talked to for 35?) which means adding extra filters, more antenna separation, etc. 

 

The 675 and 700 repeaters in Lubbock. The 675 repeater is on the tallest building for 120 miles. The antenna is 360 feet off the ground. It's running 50W at the transmitter and 40W at the antenna (which is a DB420).That's 477W ERP. It fizzles out about mile marker 41 on I27 (it's located at marker 4 roughly). The 700 repeater is a good 70 feet below it running 32W (23W at the DB420)...it fizzles out around mile marker 38. The two sites are 1000 feet away from one another. 70 feet is what mainly makes up that extra 3 miles.

 

95% of the time, you'll never notice the difference between a repeater running 200W or one running 25W if it's in a good location.

 

Great points to reiterate. I have talked to people about these time and time again. People that know enough about radio to be dangerous often think more power is better. but with these repeaters, location is everything. If your portable radio is 4 watts and the antenna height is about 5 feet when transmitting, and you can make the repeater just fine...then your repeater only really needs 4 watts at the antenna to get back to you the same. Of course, there can be other factors, but this is why those little 12w UHF industrial repeaters always worked well at manufacturing plants, you put them on the smokestack or the water tower, etc...and you had all the range you needed for the job at hand. 

 

When I worked for M we had a big plant that had 6 or 7, 25 watt UHF repeaters going....set it and forget it. I don't think we ever went back for anything on those until we moved them once. 

 

On a wider scale, we had a volunteer fire system with the "100 Watt or die" mentality. Over the years they had gotten more and more portables until that was the primary radio, and the mobiles they now had were 45 watt dash mounts. The repeater was at an awesome site, so we had their repeater set for about 50 watts, and you could always hear it at around 20 miles further than they could talk in...but that was ok, no need to talk in on a portable from 2 counties over! They never knew it wasn't running at 100 watts, they couldn't tell. 

 

The worst case of this not being heeded was a manufacturing plant on about 300 acres...with 6 VHF repeaters, and antennae on the roof (about 40 feet off the ground) and among various exhaust stack, piping, railings, AC units, etc....all things that deflect and attenuate signals. They had a "guy" that insisted on big power. Well, with 6 VHF repeaters running constantly during the busy day, that place, and a 1/2 mile around it, is a giant intermod factory! They recently narrow banded, of course, and I was told they dropped the power to 50 at the base except one repeater that's at 75-80 because the head Maintenance guy wants to hear it at his house 20 miles away....boo hoo...I'm sure this place provides him a cell phone. I heard they were advised to reduce the power...not sure if it was for the intermod issue, or the FCC reduced their power. Either way....that's up to 12 VHF frequencies on the air at once! I would venture to say 10-15 watts would work just fine on those repeaters. After all the years, still can't see why they are on VHF at all...but this point, they should be on a UHF or 800 trunk, which could be put on a on-site tower and be easier to service, etc. Oh well, not my money.