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GMRS radio as backup communication

6K views 61 replies 6 participants last post by  46camper 
#1 ·
So in another thread I asked about the Midland GMRS radio , the MXT115 as a base statio and GMRS as backup communication. Anyway I said in that thread I was going start a new thread talking about what I have and the ranges I got .
So here it is we chose GMRS because of the license fees and how easy it was to get a license. Next the radios I picked for me and others to buy were the BTech v1 GMRS HT radios .I was impressed with the ranges we got with those. In the winter with no foliage we were getting almost 3.5 miles. Then spring came we were getting only 3 miles in a complete circle around my place.
So I decided on a more powerful radio I bought a Wouxun KG805G and a Retevis RT76P radio both are 5watt radios . The range only improved a small amount. So then I had the idea of better antennas and a base station. By then my budget for preps was getting thin.
So at the time for the base station I decided to use a HT unit for the base radio. I chose one of the BTech v1 GMRS radios . Bought some RG-8x coax cable a Tram 1173 NMO antenna and Tram 1465 ground plane. The antenna is tuned for frequencies 450-470.
My results were only a little better I was able to get 4 miles . From base to radio in the vehicle.
So I bought a Midland antenna the little 7 inch antenna that comes with there MXT line of mobile radios.
I hooked it to the Retevis RT76P 5watt radio.Then I hooked the Wouxun KG805G 5watt radio to the base antenna. Now the only thing that changed was the clarity of my signal. The same range of 4 miles but a clear signal.
Again the budget I set for the communication part of my prepping was getting close to being over.
So I thought a better antenna for the vehicle was the ticket.
So I bought a Nagoya U-72G it’s tuned for GMRS. With the same radios and the U-72G . I ran some more test I my range improved about a half mile . That was from vehicle to base. The radio in the vehicle was able to pick up the signal from base right at 5miles. So then my thought was more power . So I went over budget and bought a Baofeng BF-F8HP 8watt radio tuned it for GMRS and tried it with the Nagoya UT-72G again not much change.
So I decided to try a amp. I bought a BTech U25 amp. With a 5watt radio hooked to it it’s puts out about 30watts . So I put it and the Wouxun KG805G in the vehicle. Now my signal back to base was clear and I was able to get 6.3 miles . Way beyond my original goal.
Now with the amp hooked to the base and to a 2watt BTech V1 GMRS radio . I’m able to get 7 -8 miles . That’s with the vehicle moving the whole time.
So my conclusion on my set up was to get a proper Mobile radio for a base radio. I chose the BTech UV-25x2 radio not the most powerful but it should meet my goals .
I have not done any test with it as I’m over budget with the communication part of my preps.
So soon I’m going to do some range test from base to vehicle. The vehicle will have the U25 amp hooked up to a 5watt radio .
That way I can get clear signal back to base . Also we are going to stop the vehicle in key places to see if that will improve clarity of the signal and give a more exact range. Then I’m going to test range from ht -ht with with better then the stock rubber duck antenna’s . Using some GMRS tuned Nagoya ‘s maybe another brand of GMRS antenna. I think I’m going to try the Smiley antenna also.
So expect some more test and my results .


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#4 ·
Yes most of my early test with the BTech V1 GMRS radios was clear winter day . No foliage and at around 1pm . The base to vehicle test were spring time the foliage was at full growth. It was raining.
The test with the Midland 7in antenna and Retevis RT76P 5watt radio hooked to it in the vehicle. Using the KG805G as a base radio was a rainy day mid summer. Time was at 1-2pm .
Most recent test using the Wouxun KG805G and Retevis RT76P 5 watt radios. Using the U-72G antenna. The RT76P hooked up to the U-72G for the vehicle. Then the Wouxun KG805G for the base radio. That test the weather was mid summer and clear day.
Now for testing with the BTech U25 amp with the Wouxun KG805G hooked to it and the Nagoya U-72G antenna. That test was from the vehicle to base . Base radio has been the V1 GMRS. The weather was 1-2pm clear summer day
The test using amp and V1 radio at base to vehicle. That day was clear hot and at around the same time.
Not sure when I’m going to test the new radio . I’m also going to test in the winter


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#5 ·
46camper: Sir; for continued learning. Read this article. We approach both ionosphere + groundwave with thinking. (Groundwave is typically understood uhf/vhf)
Your progress is inspiring 😁



are concerned with the ionosphere, VHF/UHF enthusiasts generally have their sights set a little lower – on the troposphere.
Under normal or flat conditions most VHF and UHF communications are generally thought to be line of sight – the higher your antennas the better.
Fortunately, reality is actually a little different thanks to the way VHF and UHF signals can be refracted. This process is the same as that seen with light. Put a pencil in a glass of water and it seems to bend. Look along a hot asphalt road in the middle of summer and it looks like water in the distance. Both of these phenomena are due to the way that the velocity of light waves changes in different media.
Another way of looking at it is that different materials have different refractive indices. The same process applies to radio waves, which are electromagnetic and therefore part of the same “family” as light waves.
If our radio wave travels from a medium with one refractive index to another bending or refraction will occur. The amount of bending will depend on the differences in the two refractive indices.
 
#12 ·
Hence why we can sometimes on CB radios hear guys in far parts of the country sound like they are next door and not be able to talk to the guy next door. Here in the KC area in my truck I have heard guys from Texas, Fla and Cali. among others sound like they are almost parked beside me. Granted they are on base units and may be using Linear amps to boost things but they do come in loud and proud.
 
#6 ·
Neophyte thanks for the link.
With that said I grew up with TV antenna and broadcast TV. Plus I grew up in a time when listening to the radio was with a antenna. In was always a guarantee in the summer that reception was crap in the summer around here . Especially in the middle of the day. Decent in the morning, crappy at noon -5 or 6 in the early evening. At time’s late at night in the summer the reception for radio and tv was amazing. You could pick up station’s far away.
So I had assumed that it was the same for two way radio.
I’m not exactly picking the best days to test range . Or the best terrain for the fact that I want to see what equipment I have will do in the worst conditions.
Plus it seems like any time I have off the weather is crappy


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#8 ·
One thing I have learned is in my area there isn’t a lot of activity on GMRS. I have also scanned amateur radio frequencies and still not a lot of traffic.
Of course CB was real popular at one time around my area.
I also know that there are a few ham repeaters but I might just be out of there range


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#9 ·
46camper: Sir; Wecome to the “Elmers” edge study 😁 Your progression 😃


The term "Elmer"--meaning someone who provides personal guidance and assistance to would-be hams--first appeared in QST in a March 1971 "How's DX" column by Rod Newkirk, W9BRD (now also VA3ZBB). Newkirk called them "the unsung fathers of Amateur Radio." While he probably was not trying to coin a term at the time, here's how Newkirk introduced "Elmer" in his column and, as it turned out, to the rest of the Amateur Radio world:
"Too frequently one hears a sad story in this little nutshell: 'Oh, I almost got a ticket, too, but Elmer, W9XYZ, moved away and I kind of lost interest.'"
Newkirk went on to say, "We need those Elmers. All the Elmers, including the ham who took the most time and trouble to give you a push toward your license, are the birds who keep this great game young and fresh."--Rick Lindquist, N1RL
 
#10 ·
Thank you Neophyte. Yea I’m planning at some point getting a Ham / amateur license, for now I’m just sticking GMRS. Although I do use my radios to listen to local Emergency services.
This weekend I plan on range testing my new mobile radio I have set up for a base radio. I will post my results and equipment that I used . It is supposed to be raining and the temperature high 90 degrees.
So I won’t get the longest range and signal clarity. Although it will give me more of a idea in a real world since and what to expect in crappy conditions.


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#11 ·
46camper: Sir; My reasoning 😁. You are making-taking major efforts 😃
id be remiss if I didn’t offer some information.

im not trying to make you HAM Radio. Amateur Radio yes 😜

These articles give you a bit more here and there. Hence. My reasoning offer.
i read / gleen information. Usining a pinch here and there.

perhaps a piece or to will guide 😁
 
#13 ·
Today I was scanning other frequencies then GMRS. I came across our local EMS frequency. That’s the one I do like to monitor. That way if there is a SHTF event I will be able to get the idea of damage has been done also areas to avoid. Now I’m trying to find or pick up local law enforcement frequencies. Although I think they use a different system. Not sure witch one though . Cool part is I can monitor different frequencies during SHTF. Then with a push of a button switch back to a GMRS channel. To communicate with In coming family and friends. Possibly be able to reroute them to my place /our meeting spot.
I still have not had the time to do any range test with the new radio. I’m also trying to figure out what to do with the BTech U25 Amp. I may set up another antenna one specifically tuned for GMRS. Hook a HT and the amp to it and use it as a longer range for GMRS only. Not sure yet . I’m thinking of possibly getting the Midland MXT105 5watt mobile radio and adding the Amp the putting it into the wife’s vehicle.
The amp works really well and it does boost the range .
I have also thought about just keeping hooked up to the second antenna useing a GMRS antenna as mentioned before. Then setting up a portable Simplex repeater/parrot. Close to my sons place that way in a emergency/SHTF situation we can communicate .
I wish I could in a way send the amp back and use the money towards another mobile radio . I think I have had it to long to get my money back . Not sure what the return policy is with BTech. I never sent anything back to them plus any item I have had trouble with BTech just replaced it . Once I showed poof of purchase.


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#15 ·
Today I was scanning other frequencies then GMRS. I came across our local EMS frequency. That’s the one I do like to monitor. That way if there is a SHTF event I will be able to get the idea of damage has been done also areas to avoid. Now I’m trying to find or pick up local law enforcement frequencies. Although I think they use a different system. Not sure witch one though . Cool part is I can monitor different frequencies during SHTF. Then with a push of a button switch back to a GMRS channel. To communicate with In coming family and friends. Possibly be able to reroute them to my place /our meeting spot.
I still have not had the time to do any range test with the new radio. I’m also trying to figure out what to do with the BTech U25 Amp. I may set up another antenna one specifically tuned for GMRS. Hook a HT and the amp to it and use it as a longer range for GMRS only. Not sure yet . I’m thinking of possibly getting the Midland MXT105 5watt mobile radio and adding the Amp the putting it into the wife’s vehicle.
The amp works really well and it does boost the range .
I have also thought about just keeping hooked up to the second antenna useing a GMRS antenna as mentioned before. Then setting up a portable Simplex repeater/parrot. Close to my sons place that way in a emergency/SHTF situation we can communicate .
I wish I could in a way send the amp back and use the money towards another mobile radio . I think I have had it to long to get my money back . Not sure what the return policy is with BTech. I never sent anything back to them plus any item I have had trouble with BTech just replaced it . Once I showed poof of purchase.


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IIRC most police agencies now a days use an 800 mhz trunked system of some type. It might be just a bit more difficult to follow them. EMS and Fire in many places possibly still use lower frequencies
 
#16 ·
information: reviews 3,000 4++ rating $100.00


Uniden BC355N 800 MHz 300-Channel Base/Mobile Scanner, Close Call RF Capture, Pre-programmed Search “Action” Bands to Hear Police, Ambulance, Fire, Amateur Radio, Public Utilities, Weather, and More, Black
 
#17 ·
I will look into the scanner neophyte. It would be I nice addition to my base radio set up .
I’m in agreement with blue fox about the 800 MHz being the frequencies the local police and Sheriffs department use . Or at least is what I have found doing research.


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#18 ·
I have not gotten to do anymore test . I have been busy maybe this weekend I will get to do some more range test. I still have yet to try my UV-25x2 . I’m certain that 25watts will get the range goals that I’m wanting . I will give a full report on my results . As promised plus a list of equipment.


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#20 ·
I forgot to mention that once I’m caught up with some house maintenance and other responsibilities. My wife said that I could spend a little more on another radio.
So I chose the Retevis RA-25 GMRS mobile radio. It’s supposed to be a 20 watt GMRS radio. So it will be put into the vehicle.
For $99 I think that if it does what I need it to do . Plus if it gets lost or stolen out of the vehicle I’m only out $100. Not $150-$200.
Plus out of all the Chinese made radios Retevis seems to always meet or comes close to there claims on the power out put of there radios.
Once I get the Retevis RA-25G I’m going to hold off on range test with it .
I want to test the BTech UV-25x2 / base radio to the amp /radio combo first. Then when that’s done I want to set up the amp and Retevis RT76P. As a secondary base radio. Then I want to test the range with that system using a separate antenna. Once I see what ranges I get with the amp/ radio combo .The amp set up will be for GMRS frequencies only. Plus I don’t know what else to do with the amp.
Wish I could exchange it for another BTech UV-25x2 radio for the vehicle.
I just don’t think BTech would go for it.
So it looks as if the amp is a secondary base system.
I might contact BTech and see what I can do . They might work with me.[emoji1696]
I can’t say that it’s not working because the amp has performed better then expected.
When I was doing the research about using amps with HT units . People were saying that the transmission from the were horrible and that they most of the time didn’t add any more power to the radio.
I can say it may not put out 40watts . On thing for sure it put out more then 5watts and almost tripled my transmission range


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#21 ·
Remember, radios at these frequencies work line of sight. Adding more power will not increase the range of the radio. You must raise your antenna. VHF and UHF radios do not propergate like a CB radio. After you install a radio into a base or mobile station, check SWR with a wattmeter designed to work at that frequency. Never transmit into an unchecked antenna.
 
#22 ·
I mostly concur with the “line of sight“ claim, but not completely. Even at low uhf frequencies (440 MHz) the signal does refract to follow ground path for quite some distance. Especially true of vhf. There is no way that NY state is line of sight from an 8 element yagi at 35 feet in a burb north of Detroit, but lots of contacts from them during vhf contests.Same can be said for Chicagoland and even Wisconsin.
 
#35 ·
What you are describing is ducting, caused by summer temps. You can't count on that for everyday comms. de KA5SIW
I think I had a post in here before about ducting which we sometimes saw jamming radars in the EF-111. As I remember it it could happened to frequencies quite high -- perhaps 3000 MHZ or more, but was more prevalent at lower radar frequencies. We got a good bounce against the NORAD FPS-117s and -124s ( one was made by GE the other by then Unisys) years ago during a test and despite being at a few hundred feet running like a scalded cat from some Fargo F-16s were still putting some pretty good strobes on their scopes (as well as screwing with the gains).

Obviously we had to break line-of-sight to do the dive and run away (bravely--one of the problems with not having any A-A missiles on the jet) so it was puzzling at first until someone explained the ducting phenomenon.

Problem is as I remember you couldn't count on it. Although the military HAD developed a radar exploiting it as I remember to look over the horizon.
 
#24 · (Edited)
No, that wasn’t tropo. It can’t be counted on regularly, but tropo is much more pronounced than that. Troop doesn’t happen in January in Michigan Lol. And to some degree an amount of atmospheric diffraction always exists. It is why beyond line of sight commo works at all at those frequenches.
Beyond GMRS, at today’s trunk ham swap I could have picked up a vhf repeater, kenwood, 2 meter band, for 200 or best offer. Granted I have no need, but just saying that ham swaps are amazing sources of good stuff. Picked up a g7-144 antenna off of an old repeater, in great shape, for a whopping 20$. I have a friend out in farm country that just got his tech license and he is having trouble getting into some of the repeaters from his farm with his current vertical at 35 feet. I am sure this vertical will help. If he doesn’t want it, I will use it myself.
 
#25 ·
46camper: Sir; as an objective.
Something narrowed down for the working com.
You are doing good.

For those play times with meteor showers -ducting lanes.
enjoy those moments.
They will come and go.
But will not be the consistent.

ka5sis perfect
reverendg perfect

in the imperfect

keep tweaking for strong consistency
You will find small tweaks that will sharpen
Signals.
I can happen 3 ways. Your son or brother are major participant. Tweaking theirs is just as beneficial
 
#26 ·
So I haven’t gotten to do any equipment and range test ,as of yet.
With that said I finally got me a SWR/power meter . It’s a Nissei RS 40. Probably not the best and most accurate meter . It will give me more of a idea on power output and what kind of SWR I’m getting .
That all helps give a better report on my range test . So now when I do range test not only I be able to list my equipment I will be able to give SWR and accurate watt vs what the manufacturer states as watts that given radio puts our. Plus I’m sure that low SWR on the antennas I’m using will give better range also.
Also from what I have found in a lot of my research is there are a bunch of guys that really give truthful information about power out put of the Baofeng radios . I have the BF-F8HP from BTech. A lot say those radios won’t do the 8 watts.
If you search hard enough you find out they are buying there radios from eBay and Amazon.
Not the same as from BTech.
In those searches the guys that know what there doing and know what to expect. Are getting the full 8 watts on the correct frequencies.
Plus alot of those guys are testing using UHF frequencies.
BTech says with the BF-F8HP 7watts UHF and 8watts VHF. I think 7.75 watts is close enough to 8 watts for me.
Anyway Tuesday or Wednesday I will know what power and SWR my radios and antennas are putting out.
I need to order another connector so I can test my base radio .


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#27 ·
So hopefully once I get all this testing done it will give others a idea of what to expect going the route of GMRS as backup communication. I know in the last 6 months I have learned a lot . If I would known what I know now it would have saved me a lot of money.
I would have skipped the BTech V1 GMRS radio and the BTech U25 amp. Also I think just for emergency communication that GMRS is fine for groups / MAGs . But you should skip the GMRS only radios and go with. Ham radios that do GMRS frequencies. The versatility of the amateur radios that can transmit on GMRS frequencies is more of what Prepers need.
Because in SHTF at some point you and your family/ group will have to communicate outside of your small group


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#28 ·
That SWR meter should be fine for your purposes. They are not complicated instruments. So long as the leads are short, the proper diodes are used, and the meter movement isn’t junk, they work pretty well.
Don’t fret too much over SWR anyways. Sure, you want a good SWR, but an antenna that gives a great SWR over a range of frequencies is likely not very efficient. Remember, a dummy load has a great SWR over a wide range of frequencies, but doesn’t put out much signal at all.
Same with power output. The final output circuit can only be so broad-banded, so power output naturally varies from one end of the band to the other. And bad SWR can give the illusion of low, or high, power output, depending on which way the SWR is off. A 2:1 SWR can be 25 ohms or 100 ohms pure resistance, or any number of other values, with added reactance. Check power into a resistive dummy load, and then you can compare to your antenna system and they should be similar. Seriously though, The difference between 7 and 8 watts is trivial, and can be explained away by all sorts of intrinsic things, even the the location of the coax. That’s especially true if no balun or rf choke is used to keep rf off the outside of the coax shield.
One thing not mentioned is audio processing, If your rigs have a speech compressor or mic gain control, use those as high as possible without distorting or clipping the mic audio. This increases the effective signal power, making the signal intelligible at longer distances. Not more watts, but more information sent using the watts available.
 
#29 · (Edited)
Thank you reverendg my mobile/base radio does have mic. gain control. I have also been experimenting with it .
I still haven’t gotten to do many range test yet with my new equipment. . I hope to do that this weekend. At least test my mobile radio .

There is one antenna that I’m looking at adding to my arsenal of antenna’s for my HT radios. It’s the Smiley Super Stick IV 465Mhz . I know it’s probably not as good for GMRS. Thing is in SHTF I may not always be on GMRS frequencies. So a little more frequency range . Gives me a lot more versatility.
Same as my base antenna it’s tuned for 400-520Mhz . So I imagine that GMRS falls in between those frequencies. My SWR won’t be perfect but reasonable.
Versatility is also I’m going to not stick with GMRS only radios. The ones I have will be given away. To help some friends and family members get started.
 
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