Concept: Dual HT repeater using MURS bridge

[WRUR259]

Disclaimer:
I want to start off by stating on the record that the concepts I want to put forth are for entertainment and information only. I do not advocate for using any equipment mentioned in the following post(s), nor do I advocate for using said equipment in any mentioned manner. Therefore, if any individual builds such a setup and runs it, I will not be responsible for any repercussions brought to said aforementioned individual in the event the black coats show up to said individual’s residence to seize said equipment or to haul said individual’s ass off to the pokey. 
 

With that being said, on with the show.

[WRUR259]

I’m a tinkerer. I have a curse that had always kept me digging deeper once an interest infected me. I was like this with PCs, then Linux, solar, now radios. I love to conceptualize and figure out how to get the most performance out of bare necessities. I’m new to GMRS, thanks to the many entertaining videos posted by Notarubicon (Props dude, I’m a huge fan).

So on with the concept. In the event of SHTF or total disbandment of a certain three letter government agency, wouldn’t it be nice to be able to reach out farther over the air using a relatively high powered repeater that you didn’t have to sink $1000 into? The technology is readily available.

I’m referring to HT’s with cross band repeater capabilities. These little gems are awesome with features that will align them with some mobile rigs. The Leixen UV-25D is fine example of such an HT. It will cross band from UHF to VHF, VHF to UHF, or both ways. The flexibility here is unbelievable, and radios such as these or the TYT UV-8000 series of radios being the foundation of such a repeater would bring features to a repeater that simply don’t exist in even high end setups. 

I intend on outlining how this setup would work, be implemented, go over the strengths and weakness I think such a system may have, and touch on added features that would come from such a setup in posts to follow. I welcome any feedback, positive or negative along the way. Ideas are strongly encouraged as this is how we all learn.

 

[WRUR259]

Disclaimer:

I know, I know “not approved equipment blah blah blah”. This is a concept, so any keyboard Karens out there can keep it to themselves. We’re not children here and we don’t need to be preached to by your highness.

So to begin, a simple repeater would of course have to be based on two radios able to match the same frequencies. To keep costs down, and to not have to worry about desensing, insertion loss, or multiple antennas in a limited space, these radios would have to be placed apart. Far apart. Like 20, 30 or even 50 feet apart. One HT of coarse will be the receiving unit, the other will be the transmitting unit. 
The interface between the two radios I will dub the “MURS bridge”. This bridge is where that added functionality will come from, but more on that later.

[axorlov]

Why don't we have a dislike button here, anybody knows? Or better, "stomp into cow manure" button.

[tep182]

2 minutes ago, axorlov said:

Why don't we have a dislike button here, anybody knows? Or better, "stomp into cow manure" button.

 

 Mencken said something about "the haunting fear that someone, somewhere, may be happy"...

[WRUR259]

Hi tep182. Welcome to the thread. I hope you’re doing well.

[WRUR259]

The receiving radio will be set to low power, as the only transmission taking place from this radio will be a low powered MURS signal in the VHF band  the 20 feet or so to the transmitting radio upon receiving the 467.xxx signal.

The transmitting radio will then receive the VHF signal and send it out on the UHF band on the corresponding 462.xxx channel. This channel could be set on high power, or could be routed through a UHF amplifier like the Btech unit for an even higher output - up to 50 watts!

Even setting an HT such as the UV-25D to high power without the amplifier could yield and output of 18-20 watts.

This is a relatively inexpensive portable option that can be deployed with ease, but it can be improved. 

[axorlov]

44 minutes ago, tep182 said:

Mencken said

You mean the "gnawing worry"? You free-flying rebels are funny. Keep up your free-spirited, but useless and harmless experiments. Don't forget to keep us all posted, we will enjoy your fruitless hunt.

20 minutes ago, WRUR259 said:

or could be routed through a UHF amplifier like the Btech unit for an even higher output - up to 50 watts!

I ROFLed here. Up to 50 watts, with Baofeng! Crazy stuff, Imma telling ya

 

[WRUR259]

6 minutes ago, axorlov said:

You mean the "gnawing worry"? You free-flying rebels are funny. Keep up your free-spirited, but useless and harmless experiments. Don't forget to keep us all posted, we will enjoy your fruitless hunt.

I ROFLed here. Up to 50 watts, with Baofeng! Crazy stuff, Imma telling ya

 

Thank you for your engagement. Hope you’re doing well!

[SteveShannon]

In this case Alex is right. The owner of this site probably doesn’t want to have a thread that teaches people to flagrantly disregard regulations. 
Now if you wanted to publish almost exactly the same thread in the ham radio area and aim it at doing a cross-band VHF/UHF repeater, nobody could complain. 

[WRUR259]

21 minutes ago, Sshannon said:

In this case Alex is right. The owner of this site probably doesn’t want to have a thread that teaches people to flagrantly disregard regulations. 
Now if you wanted to publish almost exactly the same thread in the ham radio area and aim it at doing a cross-band VHF/UHF repeater, nobody could complain. 

Well, they could. However I do appreciate the concerns you have brought to light in such a diplomatic fashion. You sir, are a shining example to us all and your statement is worthy of consideration. With that, I will end my input on this subject and I appreciate you kindly pointing out to me the error of my ways. This was intended to be a thinking exercise, but I see now see how it can be interpreted. You have a wonderful day.

[KAF6045]

18 hours ago, WRUR259 said:

The receiving radio will be set to low power, as the only transmission taking place from this radio will be a low powered MURS signal in the VHF band  the 20 feet or so to the transmitting radio upon receiving the 467.xxx signal.

The biggest problem is that you are not just "cross-banding" (which essentially only exists in Amateur usage as that service has multiple bands). You are "cross-service" linking: GMRS -> MURS -> MURS -> GMRS.

That also opens up the problem that, someone with a MURS radio that is configured with the same channel and tone, is going to be picked up by your output radio, and repeated in the GMRS band -- AND DOES NOT HAVE A GMRS LICENSE/CALL.

Also, there are only five MURS channels vs eight GMRS main/repeater channels. Three of the MURS channels are narrowband-only! (4&5 are wideband with narrow optional). Proper GMRS is wideband.

[WRUR259]

3 hours ago, KAF6045 said:

The biggest problem is that you are not just "cross-banding" (which essentially only exists in Amateur usage as that service has multiple bands). You are "cross-service" linking: GMRS -> MURS -> MURS -> GMRS.

That also opens up the problem that, someone with a MURS radio that is configured with the same channel and tone, is going to be picked up by your output radio, and repeated in the GMRS band -- AND DOES NOT HAVE A GMRS LICENSE/CALL.

Also, there are only five MURS channels vs eight GMRS main/repeater channels. Three of the MURS channels are narrowband-only! (4&5 are wideband with narrow optional). Proper GMRS is wideband.

Yes, and as Sshannon pointed out, this concept belongs in ham where one can use the lower frequencies in the 70cm and 2m bands so this horse is already dead. I had already considered the potential ramifications and possible solutions for a “mixed bag” of canned frequencies that were going to be addressed later in the thread, along with linking independent repeaters but at this stage, it’s all moot. I’m absolutely sure that many hams are already doing what I envision, but I dreamed it up myself and I realize that the best path forward for me is to get my ham license. Thanks for your input, and please have a blessed day.

[SteveShannon]

25 minutes ago, WRUR259 said:

Yes, and as Sshannon pointed out, this concept belongs in ham where one can use the lower frequencies in the 70cm and 2m bands so this horse is already dead. I had already considered the potential ramifications and possible solutions for a “mixed bag” of canned frequencies that were going to be addressed later in the thread, along with linking independent repeaters but at this stage, it’s all moot. I’m absolutely sure that many hams are already doing what I envision, but I dreamed it up myself and I realize that the best path forward for me is to get my ham license. Thanks for your input, and please have a blessed day.

There are a few pretty neat mobile ham radios that can be configured as cross-band repeaters without needing two separate radios. The Yaesu FTM-6000 is an example at a price of $270. 
It has two separate VFOs. 
If you want digital modes there are models from Alinco, Anytone, and Yaesu that do that as well. 

[MichaelLAX]

What great “out of the box” thinking.

It seems to me that instead of GMRS, FRS/MURS would be a better pair. 

[WRUR259]

4 hours ago, Sshannon said:

There are a few pretty neat mobile ham radios that can be configured as cross-band repeaters without needing two separate radios. The Yaesu FTM-6000 is an example at a price of $270. 
It has two separate VFOs. 
If you want digital modes there are models from Alinco, Anytone, and Yaesu that do that as well. 

Yes, TYT has a nice mobile unit capable of cross banding as well. The whole purpose for two radios was to give a single band user a single band experience using typical offsets - ie UHF in, UHF out.

The VHF only acts as a bridge between the two or the “connecting cable”. However, this bridge has a mountain of potential, using offsets as well it can link repeaters.

Crap, I was supposed to be done here. It just consumes me going when my head starts building something.

[WRUR259]

1 hour ago, MichaelLAX said:

What great “out of the box” thinking.

It seems to me that instead of GMRS, FRS/MURS would be a better pair. 

Thank you. 

In a perfect world, you are correct. However, FRS HT’s can’t do offsets - at least none I know of.

[MichaelLAX]

Check this out!

[WRUR259]

9 hours ago, MichaelLAX said:

Check this out!

That is pretty cool.