Author Topic: GMRS/MURS: Non-Ham Comms Solution for the Ready Minded  (Read 1056 times)

Offline SCWolverine

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GMRS/MURS: Non-Ham Comms Solution for the Ready Minded
« on: May 31, 2018, 01:54:57 PM »
Here is a little something I put together this afternoon for my family to use here on the farm.

It consist of a GMRS Transceiver as well as a MURS Transceiver.

We utilize the MURS with the Dakota Alert Driveway and Proximity Sensors and the newly added GMRS gives us some flexibility with mobile/handheld units to boot.



you can see everything is stacked upon a little old Radio Shack 12v power supply, which seems to provide plenty of power to allow both stations to monitor their respective frequencies.

The 2 radios (MURS=VHF and GMRS=UHF) Transmit and Receive through the same antenna mounted on the chimney.  They share the same feed-line (coax cable) by utilizing what some call a Duplexer and others a Diplexer....either way, it's a low cost device that prevents an opposing frequency from entering the wrong radio at the wrong time.



The radios are connected to the Duplexer with 2 short coaxial jumpers and then head outside and up the chimney to a Ham Radio Tuned Dual-band (VHF/UHF) Arrow Jpole Antenna.



MURS is licenses free and is a well-kept secret in the Ready-Comms world.  GMRS requires a licenses from the FCC ($70) to keep yourself and family legal.

I have yet to do any distance testing but plan to get on that straight away. 

MFJ Duplexer:
http://www.mfjenterprises.com/Product.php?productid=MFJ-916B

Midland GMRS Mobile:
https://brickseek.com/walmart-inventory-checker?sku=54085122

Radio Shack 19-1210 (discontinued-sometimes avail on ebay):
http://mark-rodgers.com/MURS/191210mobile.html

Arrow JPole Antenna (MURS/GMRS model avail:
http://www.arrowantennas.com/osj/j-pole.html

Before you mention it, yes I know your chi-com walkie talkie will do all of this and more-just not legally...I'm that guy.

Offline Carl

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Re: GMRS/MURS: Non-Ham Comms Solution for the Ready Minded
« Reply #1 on: May 31, 2018, 04:52:45 PM »
  Some China Talkies are commercial approved and also workable. At the apparent height of your base antenna ,I would expect about 12 miles to a mobile with a good mobile antenna ,or even a talkie with a good mobile antenna as line of sight and height above terrain are your primary limiting factors. Good looking setup SCW! Location of hills in your area will allow for greatly extended range .  Plus some KARMA for great post.

Offline Alan Georges

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Re: GMRS/MURS: Non-Ham Comms Solution for the Ready Minded
« Reply #2 on: May 31, 2018, 06:16:59 PM »
Nice work, and thanks for the duplexer link.

Offline cidyl

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Re: GMRS/MURS: Non-Ham Comms Solution for the Ready Minded
« Reply #3 on: June 02, 2018, 07:07:58 AM »
The RS 19-1210 isn't legal for use on the MURS frequencies unless you held a Part 90 license to operate on those frequencies prior to Nov 2000 and were grandfathered in.  The 19-1210 is a Part 90 radio with a 5w output.  MURS radios must be certificated for use under part 95 and are limited to 2w.

But don't take that the wrong way, I like it and we use a similar setup.  It's not like any individual ever got fined by the FCC for a type certification violation or for using 5w on MURS either.

Offline SCWolverine

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Re: GMRS/MURS: Non-Ham Comms Solution for the Ready Minded
« Reply #4 on: June 02, 2018, 07:33:26 AM »
well dang. 
Mic D/C'd on MURS rig to monitor sensors (we have no other stations to talk to anyways).
GMRS arrived at perfect time for the fam: W_B_237
« Last Edit: June 02, 2018, 07:53:15 AM by SCWolverine »

Offline cidyl

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Re: GMRS/MURS: Non-Ham Comms Solution for the Ready Minded
« Reply #5 on: June 02, 2018, 07:56:59 AM »
Well then again, there's a lot of anecdotal evidence that the output power is automatically limited to 1 watt on MURS freqs.  The FCC filing for certification (https://fccid.io/AAO01901210) shows it has 850mW and 5 watt RF outputs, but nothing on the whether it's fixed at 850mW for MURS. 

Maybe it is legal?

ETA: Legal, apparently.  It's limited to 1w on MURS channels automatically provided you don't own a tweaker.   See "Going Mobile With MURS" http://www.americanradiohistory.com/Archive-Popular-Communications/00s/Popular-Communications-2003-12.pdf

That would seem to violate 95.649, "No CB, R/C, LPRS, FRS, MedRadio, MURS, or WMTS unit shall incorporate provisions for increasing its transmitter power to any level in excess of the limits specified in ยง 95.639." but whatever.
« Last Edit: June 02, 2018, 08:28:16 AM by cidyl »

Offline Carl

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Re: GMRS/MURS: Non-Ham Comms Solution for the Ready Minded
« Reply #6 on: June 02, 2018, 08:36:15 AM »
Well then again, there's a lot of anecdotal evidence that the output power is automatically limited to 1 watt on MURS freqs.  The FCC filing for certification (https://fccid.io/AAO01901210) shows it has 850mW and 5 watt RF outputs, but nothing on the whether it's fixed at 850mW for MURS. 

Maybe it is legal?

  I would use the radio on MURS as the 3DB difference in output is minimally even noticeable as the MURS power restriction is limited to 2 watts for the type acceptance at manufacture and the fact that your older radio can output more is of little worry ,unless you bring attention to yourself by interfering with  users
who paid for business use of the band and this will bring attention to you way faster than any power or antenna restrictions.It is good to have knowledge of the laws of radio use ,even though most laws are set more for type acceptance/manufacture of radios than consumer use...this is why most China radios are sold as HAM radios as they do not have TYPE ACCEPTANCE for commercial band use. I have NEVER been even asked what radio or power I use on FRS,GMRS,MURS by any person....though it is a popular question on Ham radio.  Don't make trouble,there won't be trouble.

Offline SCWolverine

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Re: GMRS/MURS: Non-Ham Comms Solution for the Ready Minded
« Reply #7 on: June 02, 2018, 10:40:23 AM »
 :)