RCM

That antenna along with many others on the market, reminds me of something I heard about fishing lures: they're designed not so much to catch fish, but to catch fishermen.
 
Generally speaking, the shorter the antenna and the wider its bandwidth, the less gain it has. A better way to state it is the more loss it has.

That antenna along with many others on the market, reminds me of something I heard about fishing lures: they're designed not so much to catch fish, but to catch fishermen.
 
Generally speaking, the shorter the antenna and the wider its bandwidth, the less gain it has. A better way to state it is the more loss it has.

I actually run both on my F150. The only benefit of the 4503 is size. It works well on my local trunking systems but no antenna will work there. For GMRS its ok when on some repeaters, but simplex is junk. I since have put the 1/4 wave back on my GMRS mobile and am very happy with it. 

BTW, I honestly don't understand why you just don't go with a simple 1/4 wave NMO mount antenna. They are dirt cheap, and easily replaced. A fiberglass antenna, no matter how rugged, will shatter if it hits a low hanging branch, overhead rocks, or even the ground (for flipper). A simple metal 1/4 wave will just bend over and can be straightened out in seconds (or replaced with a spare).

You have mentioned the suitability of an antenna for repeaters and simplex as though the two things are inherently different.  Well, to some (very tiny) extent they are, in that with a repeater your transmit and receive frequencies are 5mHz apart, so there is a small degree to which an antenna might be tuned differently depending on whether the main use was simplex (tuned right on frequency) or duplex (somewhere between the Tx and Rx).  But, that is really pretty insignificant.
 
On the other hand, an antenna's  radiation pattern can make a difference depending on the physical relationship between two stations talking simplex,  or a station talking to a repeater.  But, since many repeaters are actually located pretty close to the ground, like on roof tops, and two stations on a jeep trail could be several hundred vertical feet apart, you can't really say any particular "gain" pattern is better for one or another.  However, as others have noted, a simple 1/4 wave may well be the best compromise, especially in a situation where both stations are in motion.

Okay, I'm hooked.
 
I was walking out to our local crop share pickup today when a neighbor texted me and asked if I knew what the huge plume of smoke is rising from near Alexandria, Virginia. Nothing (yet) on the news.
 
I had my radio with me because I was doing a couple of antenna/signal tests anyway, so I hopped on the local repeater and asked for anyone nearby to provide a visual situation report. Within a minute, I had 3 separate responses.
 
Turned out to be a huge construction fire, now at 5 alarms.
 
The local news story hit their web site and alert system > 30 minutes later. (See https://wtop.com/fairfax-county/2020/02/massive-fire-engulfs-fairfax-county-construction-site/)
 
No big deal, I suppose, but I will add that from my vantage point, the smoke was along the glide path into DCA (Reagan National) airport. I'm the son of a retired 747 pilot (and fighter/aerobatics RAF team), so big plumes of smoke near airports have always made me uneasy, since long before 9-11.
 
Anyway, LOVE my GMRS comms now that I've learned about the world of repeaters out there. I'll be taking my Ham technician class exam in a couple weeks as well.
 
I'm hooked.
 
Cheers,
 
Ken (WRFC318)
 

Your best bet is to use the coax that comes preinstalled on the NMO mount. This cuts out SWR issues caused by poor solder jobs and takes less time at that point. With such a short run you shouldn't have much loss. I can tell ya upfront installing anything the size of LMR400 in a vehicle, then attempting to attach it to an NMO connection and your just asking for a troublesome install. (LMR400 doesn't flex easily and is quite thick, about 1/2 inch.)

Alan,
 
Just an FYI.  I just went through exactly what you're doing.  I ended up with a Kenwood TK-880-1 V2 @ 25w from used-radios.  You can do some searching on this forum for the benefits (or not) of 40w over 25 (draws 12A vs 8A on TX, is 1" deeper).  I'm still considering the 880H for my pickup with more room to mount and dual battery reserve (not that I intend to TX from the SxS for long w/o it running).  Installed mine in a 2019 Yamaha Wolverine X4.  I think I'm going to like it.  Got a couple HT as well to hand out to family when on the trail.
 
Lots of help here and I've covered a lot of the questions you might have. You can search my posts for the answers I got on the topic.  Or chime in with me and I'll do what I can.

Alan; go for it....It is best option as it will do wideband mode as GMRS permits. The Midlands and cheaper radios don't.

I'll keep that in mind...

You would lose, not gain signal by moving the antenna down 15 inches to that tool box. If you can't bring yourself to drill a hole for a proper antenna, then get a better mag mount than the stock Midland (which is junk) with a better coaxial cable, (not that ultra-thin 174 junk that Midland uses) and leave it on the roof.  THAT is where you will get best results on UHF.  Even just a better 6" quarter-wave with a good cable and lager, low capacitance mount will beat the Midland quarter wave.

Hey there. We cannot direct link to software or firmware due to copyright issues (To my knowledge anyways) However, if you message me your E-mail I can send you the firmware package I used.

I will need to know if the 880 is Version 1 or 2. This can be determined on the sticker on the back of the radio (Version 2 radios will say Version 2.0)
Other than that, your 49D software disk should have a program called FPRO. This is used to update radio firmware. Ill include more detailed information when I send the firmware.

I'm skeptical about buying off Ebay but it sounds like lots of folks have good luck there.  Assuming that's where you get them.   I spend the extra to get a 90 day warranty and to be sure it works out of the box.  I have no interest in getting 2 or more to 'make' one good one.  If you find one you're passing on, pass it on to me if from a reputable seller and I'd consider it.. kidding, sort of..
 
Regardless of where I buy, I am leaning toward another 880 in the pickup.  The UTV install turned out well IMO so will see how much use it gets this summer on the trails, etc.
 
Yeah, repeater.  Don't need one at home, there's already two within easy reach of both my HT.  I have a piece of dirt in Montana that would be close to ideal @ 5600', open with no trees or big buildings, looking over a good size town several hundred feet below and a couple valleys that stretch a long way.  Closest repeater to that area is well over 100 mi. LOS and behind a few 10k ft. mountain ranges.  Also happens to be at the junction of two major interstate highways.  But I don't live there, visit a couple times a year only, so it would be more of a GMRS community service, if there's even a GMRS "community" in the area.  Build it and they will come.
..and I know squat about requirements, as in enclosures, tower/pole, batteries with solar I'm assuming would be the ticket.  Maybe I could find someone to maintain it for their group or such.  Anyway..

Last TK-880 I bought didn't cost much more than a PL259-SMA adapter. In fact I passed on some just last week that were $15 each.
If I were you I would put the 880 in the UTV, get another one for the truck, and probably a couple more as backups. But that's just how I roll!
 
I was actually thinking awhile back that I had several TK-880s. But I started looking for them and could only find one that wasn't already in a vehicle. So I looked around for some cheap ones and bought three more for just over $20 each.
 
You're gonna need two for your repeater! What repeater, you ask? Just wait!

IMHO - you don't have an antenna problem. You've got a radio problem. 3.5 miles with 40 watts in relatively flat terrain in mid Ohio is not a line of sight problem.
 
Those Midlands are quite honestly garbage. You are going to spend a lot of time (and money) trying to make those units perform like actual radios should. Go buy some used Kenwood/Motorola/Vertex radios programmed to GMRS (which will end up costing half as much and work three times better).

I have no problem with NWI. I hop on from time to time. My only problem is having free time to devote to the hobby.
 
 
Sent from my iPad using Tapatalk

Also run a FCC search for the coordinates. You mentioned the license was cancelled. Back in my shop days we did a lot of LMR and a few times would add a site like this to our license especially if we had a chance to sell other on the system in a fringe area. Once you determine there is nothing connected to the antenna and it is indeed UHF find someone to sweep the antenna for Return Loss and DTF to verify the line and antenna is good. Once that is determined and a deal can be made with the owner, then start assembling your parts for a repeater. As I have said other times if you do build the repeater yourself image is every thing. Most customers/site owner dont want to see mobile or portable radios wire tied to a sheep of metal or power supply. Make it neat. Quality jumpers for the duplexer with no adapters and you will have a decent repeater.
 
Site lease/costs is a big unknown. Do some research and talk to the owner. A lot of times you can work something out especially if its a local agency. If its American or Crown walk away as your going topay many thousands a year. When our SAR team first put a repeater online we worked out a deal to mow and maintain the building at an old tower site in exchange for rent. Worked great for years.

I was sort of imagining a civilianized version of the military radios that share a common backplane a while ago -- something that'd fit in a double-DIN stereo slot, with separate radios, and a shared screen and mic.  Seems like it has potential to work really well with an auto-voting mic like you're imagining.

… Those exist?

Yay! Persistent application of cognitive energy pays off finally!

You can do that on most of the Kenwoods. Here it is, in the TK-3180 manual: https://www.manualslib.com/manual/1656566/Kenwood-Tk-3180.html?page=86#manual
 
 
"This function allows you to change the Decode/Encodecombination of the QT/DQT Signaling without changingthe transmit/receive frequencies.This is used when there are several Talk Groups usingQT/DQT codes on the same frequency.You can configure a maximum of 40 pairs of OST QT/DQT Decode and QT/DQT Encode to the OST table. TheQT/DQT Encode/Decode pair and the OST table areswitched when the PF OST key is pressed."

You should be able to get full-scale copy at 3.5 miles on less than 2 watts.  If you can't do it at 40 Watts, then lose those junk Midland antennas, and get a couple of decent UHF omni antennas mounted on the roofline.  Also run a heavy, large gauge coax cable designed for UHF...such as LMR-400.  If you have those Midlands with that thin RG-174 type coax, then that is exactly why you can't get 3 miles.  If you need to extend the coax, note that the CB coax extenders you buy at the truck stop will not work at UHF.

I would only opine that there is no magic that comes with a Technician license over GMRS. It's practically the same physics at play. I'm facing a different problem, but also physics related. I live in a dip that breaks LOS in the direction that I need coverage. GMRS focuses my solutions to the GMRS band, whereas the amateur solution spreads me over several bands, which equal more $
 
The only exception would be HF, which would do a better job at distance. 
 
Otherwise, I'm focused on doing GMRS really well as I can tune everything to be excellent at those frequencies. 

Sorry to hear that.  I'm not sure what your goals are, but I have been a Ham for close to 18 years and GMRS is a fantastic service that I use regularly. The thing about radio service is to use the proper service for the comms you are trying to have.

Omni's fall into a similar issue.  While there are some dual-band 2m/70cm vertical antennas that cover from 440-470 MHz, the gain is very low.  As gain increases, the bandwidth narrows and so does the takeoff angle, impacting sensitivity between stations with elevation difference.
 
So, if you have the expendable income, you can test it.  However, don't be surprised if the lower gain of a broad band antenna doesn't help much.
 
I have to agree with RCM on getting two service-dedicated Larsen welded Yagis.  That's going to be your best bet, relating to both performance and price.