GMRS Base Radio Questions

[Squaregrouper]

I recently went the legal route for GMRS (WRWJ564) and have a few questions...
The main purpose of getting these radios is for SHTF and I'm also interested in having them for places without cell service. I am concerned about line of sight between two radios, especially if repeaters are not accessible. Then I started looking into making or buying my own repeater.
Question #1- I came across this base radio and am under the impression this would also function as a 40w UHF repeater. If so, logic says I could set it up at home (or elsewhere) and be able to use handheld radios 5+ miles apart.
Question #2- If it can be used as a repeater, is making it pseudo private as simple as having the offset say, +7 instead of +5? I would want it to be "my" repeater and not readily available to any random Joe.
.

Wouxun KG-UV920P-A Dual Band Base/Mobile Two Way Radio

The Wouxun KG-UV920P-A is a Dual Band UHF/VHF base/mobile two way radio with dual speakers and dual output.

www.buytwowayradios.com

 

[lazarus]

I recently went the legal route for GMRS (WRWJ564) and have a few questions...
The main purpose of getting these radios is for SHTF and I'm also interested in having them for places without cell service. I am concerned about line of sight between two radios, especially if repeaters are not accessible. Then I started looking into making or buying my own repeater. I came across this base radio and am under the impression this would also function as a 40w UHF repeater. If so, logic says I could set it up at home (or elsewhere) and be able to use handheld radios 5+ miles apart.
.

Wouxun KG-UV920P-A Dual Band Base/Mobile Two Way Radio

The Wouxun KG-UV920P-A is a Dual Band UHF/VHF base/mobile two way radio with dual speakers and dual output.

www.buytwowayradios.com

That's not for GMRS, but HAM. You can tune it to the GMRS frequencies unless they locked those out in the firmware. You are not supposed to use HAM on GMRS even if you are legal on both. Stupid, but it is there.

This would also only work as a cross band repeater. So you can pickup UHF and retransmit on VHF and so on.

If you want a cheap ammo can repeater get this https://www.argentdata.com/catalog/product_info.php?products_id=98

Then you just need the appropriate cable for your radio. Simplex. Store and forward. I've read things that this is not allowed and plenty who say it is fine. I see nothing wrong with it in general. Mine works great. With my home station, a DB-25g with a 6dBi antenna in the attic I can cover my entire neighborhood just fine. The house is on a slight ridge and I can easily hit anything within LOS with handhelds using the repeater. That said, even without that, with my handhelds and the right antenna I can stretch out 50 miles fine, with limited obstruction. My DB-25g in my car with the extra radio power reaches out cleaner, but you are only talking around 4dB signal strength difference between a 5w and a 20w radio. GMRS can do NLOS, of course not as well as VHF can. I can get around a quarter mile and maybe 50ft vertical below the horizon from my house from the crest of a hill nearby (about 2 miles total distance) before I start losing reception entirely.

Separately, I can hit the EC repeater from my house and it is NLOS, not LOS, about 14 miles away from my DB-25g and attic antenna.

A BTech UV-5g, extended battery, Argent repeater and a nice Nagoya 770g on the ammo can lid can be carried easily and be made waterproof for a solid day of use as a repeater (maybe longer) depending on talk time. Easy enough to get the 12v adapter, install a small deep cycle lead acid battery and a solar panel and stash it somewhere to run indefinitely.

 

[Squaregrouper]

That's not for GMRS, but HAM. You can tune it to the GMRS frequencies unless they locked those out in the firmware. You are not supposed to use HAM on GMRS even if you are legal on both. Stupid, but it is there.

This would also only work as a cross band repeater. So you can pickup UHF and retransmit on VHF and so on.

If you want a cheap ammo can repeater get this https://www.argentdata.com/catalog/product_info.php?products_id=98

Then you just need the appropriate cable for your radio. Simplex. Store and forward. I've read things that this is not allowed and plenty who say it is fine. I see nothing wrong with it in general. Mine works great. With my home station, a DB-25g with a 6dBi antenna in the attic I can cover my entire neighborhood just fine. The house is on a slight ridge and I can easily hit anything within LOS with handhelds using the repeater. That said, even without that, with my handhelds and the right antenna I can stretch out 50 miles fine, with limited obstruction. My DB-25g in my car with the extra radio power reaches out cleaner, but you are only talking around 4dB signal strength difference between a 5w and a 20w radio. GMRS can do NLOS, of course not as well as VHF can. I can get around a quarter mile and maybe 50ft vertical below the horizon from my house from the crest of a hill nearby (about 2 miles total distance) before I start losing reception entirely.

Separately, I can hit the EC repeater from my house and it is NLOS, not LOS, about 14 miles away from my DB-25g and attic antenna.

A BTech UV-5g, extended battery, Argent repeater and a nice Nagoya 770g on the ammo can lid can be carried easily and be made waterproof for a solid day of use as a repeater (maybe longer) depending on talk time. Easy enough to get the 12v adapter, install a small deep cycle lead acid battery and a solar panel and stash it somewhere to run indefinitely.

My goal is handheld to handheld for 5 miles regardless of terrain. Would this accomplish that?

 

[6-Pack]

Are you on a hill? UHF repeaters would be best on top of a hill.

You legally need GMRS radios and legally can’t use other radios (such as ham radios). I’m not saying it’s never been done, but this is the legal answer.

If you hit a 5W repeater you should easily get quite a few miles as long as the repeater has a good antenna, is as high as possible, and the repeater had a good output. 40W should be fine. Just be aware of duty cycles and longevity of your repeater transmitter.

 

[lazarus]

My goal is handheld to handheld for 5 miles regardless of terrain. Would this accomplish that?

If there is no line of sight to the repeater, or near line of sight, no. Terrain is king and height of the antennas is queen.

Without repeaters 5 miles is no problem handset to handset if you have line of sight. Woods or city will cut that down, but if you have line of sight through a forest a few miles is still just fine. You’d want higher gain antennas on the HTs, not just near no gain 1-2dBi rubber duckies. Urban terrain will drastically cut down range unless you are on a roof top.

 

[jc1240]

If I recall GMRS repeater input/output frequencies are established by the FCC and are 5kHz apart. I don't think going with 7 is valid; you'll be outside the GMRS band.

There is no privacy with GMRS. You can set "privacy tones" but all they do if you set one is block your radio from allowing you to listen to someone on the same frequency who doesn't use that same tone. They can hear you just fine unless they too set a tone and one different from yours.

A true repeater can have an input tone, but those can be found by scanning for them when someone is transmitting. In your case you may not have a problem if you aren't babbling for long periods and the chances of somone is in range and wants to hop on are probably low. Basically possibility vs probability.

I don't know anything about cost and it's been months since I've seen this video, but one of my favorite youtubers who puts out a bazillion GMRS videos did a test of a Retevis RT97 repeater.



And the midland MXR10 (I don't know if has a newer video on this with a "real world" test).

 

[Squaregrouper]

If I recall GMRS repeater input/output frequencies are established by the FCC and are 5kHz apart. I don't think going with 7 is valid; you'll be outside the GMRS band.

There is no privacy with GMRS. You can set "privacy tones" but all they do if you set one is block your radio from allowing you to listen to someone on the same frequency who doesn't use that same tone. They can hear you just fine unless they too set a tone and one different from yours.

A true repeater can have an input tone, but those can be found by scanning for them when someone is transmitting. In your case you may not have a problem if you aren't babbling for long periods and the chances of somone is in range and wants to hop on are probably low. Basically possibility vs probability.

I don't know anything about cost and it's been months since I've seen this video, but one of my favorite youtubers who puts out a bazillion GMRS videos did a test of a Retevis RT97 repeater.



And the midland MXR10 (I don't know if has a newer video on this with a "real world" test).

I have been watching a ton of his videos. He loves the HAM commenters.

 

[gamer_jim]

I've been a ham for 10 years but new to GMRS. From what I am reading it looks like the only way to have a private GMRS repeater is to use unpublished tones. You can also ask someone to not use your repeater and if they persist you can file a complaint with the FCC.

 

[dblas]

I recently went the legal route for GMRS (WRWJ564) and have a few questions...
The main purpose of getting these radios is for SHTF and I'm also interested in having them for places without cell service. I am concerned about line of sight between two radios, especially if repeaters are not accessible. Then I started looking into making or buying my own repeater.
Question #1- I came across this base radio and am under the impression this would also function as a 40w UHF repeater. If so, logic says I could set it up at home (or elsewhere) and be able to use handheld radios 5+ miles apart.

Yes, but you have to pick one of the 8 repeater pairs.

Question #2- If it can be used as a repeater, is making it pseudo private as simple as having the offset say, +7 instead of +5? I would want it to be "my" repeater and not readily available to any random Joe.
.

Wouxun KG-UV920P-A Dual Band Base/Mobile Two Way Radio

The Wouxun KG-UV920P-A is a Dual Band UHF/VHF base/mobile two way radio with dual speakers and dual output.

www.buytwowayradios.com

No, you cannot change the split on your repeater, you have to use the FCC mandated pairs. As for making it private, you can use a really obscure PL tone on transmit and an equally obscure PL tone on receive.

 

[dblas]

My goal is handheld to handheld for 5 miles regardless of terrain. Would this accomplish that?

Handheld to handheld or handheld to repeater?
Handheld to handheld regardless of terrain is an issue with 5W.
Handheld to repeater regardless of terrain, is feaseable with the right repeater set-up.

 

[Squaregrouper]

Handheld to handheld or handheld to repeater?
Handheld to handheld regardless of terrain is an issue with 5W.
Handheld to repeater regardless of terrain, is feaseable with the right repeater set-up.

I was quoting post #2- specifically the argentdata link Lazurus posted.

 

[dblas]

I was quoting post #2- specifically the argentdata link Lazurus posted.

Bite the bullet and buy a real repeater that transmits and receives at the same time, instead of a store and forward "gimick".
I've never liked store and forward systems, they only use one frequency and are notoriously unreliable.

 

[Ponder_MD]

You can't use your single radio as a repeater. You need to pair them or buy a dedicated repeater.
The videos linked by jc are excellent.

To locate a list of repeaters that are in your area that you might use:
repeaterbook.com
mygmrs.com then click "Repeaters" along the top of the page.

It appears that neither of those sites contain all of the repeaters so you kind of have to use both pages to get the complete list. You'll notice that some of them say "need permission" and some say "open." You can email the repeater owner to gain permission and get the CTCSS tones needed to access the repeater.

Right now, range is "better" due to the cool, dry air and the trees being leafless. Expect range to decrease as the humid summer air arrives and the trees leaf out. These factors impede transmission somewhat. That's why gain and antenna height are key.

 

[dblas]

You can't use your single radio as a repeater. You need to pair them or buy a dedicated repeater.
The videos linked by jc are excellent.

To locate a list of repeaters that are in your area that you might use:
repeaterbook.com
mygmrs.com then click "Repeaters" along the top of the page.

It appears that neither of those sites contain all of the repeaters so you kind of have to use both pages to get the complete list. You'll notice that some of them say "need permission" and some say "open." You can email the repeater owner to gain permission and get the CTCSS tones needed to access the repeater.

Right now, range is "better" due to the cool, dry air and the trees being leafless. Expect range to decrease as the humid summer air arrives and the trees leaf out. These factors impede transmission somewhat. That's why gain and antenna height are key.

Both of those are woefully incomplete, I am aware of at least 8 repeaters in the DC metro area that are not on either list. The best way to find an "open" pair is to listen to the output of a repeater pair for a week or two and see if you hear anything, leave the radio on open squelch to hear anything and everything on the frequency.

 

[Chat-Bot]

Here are places you can look up repeaters that "may" be active.

https://mygmrs.com/repeaters

https://www.repeaterbook.com/gmrs/Display_SS.php?state_id=24

 

[Mark75H]

My head spins

 

[dblas]

Here are places you can look up repeaters that "may" be active.

https://mygmrs.com/repeaters

https://www.repeaterbook.com/gmrs/Display_SS.php?state_id=24

As I stated above, neither of those are complete, as there are at least 8 repeaters in the Baltimore/DC area that are not on either page. And there is no requirement for anyone to add their repeater. This isn't amateur radio where all of the repeaters are coordinated, and there is no requirement for GMRS repeaters to be coordinated, but it make for good radio if they are between repeater owners.

Again, the best way to find a clear repeater pair is to listen on a certain pair for a week or so.

 

[K31]

My head spins

I you hook up some power to it you could make an oscillator and with a few more components have a radio.

 

[Mark75H]

I you hook up some power to it you could make an oscillator and with a few more components have a radio.

Sparks would fly. I don’t think that type of transmitter is allowed anymore.

 

[dblas]

Sparks would fly. I don’t think that type of transmitter is allowed anymore.

It depends....How large is the air gap between your ears?