Advantage of split codes on GMRS repeaters

[DonErle]

What are the advantages of having different squelch codes on the TX and RX side of a GMRS repeater? Is it more common than using the same code on each?

[axorlov]

If you want to keep repeater private, you may set a different input tone, that it's not so easy to be scanned. Thus, repeater owner can control, to some extent, who can use the repeater. Also, till recently, only the good quality Part 90 and Part 95 radios were able to do split-tones. Using split-tones it is a way to keep people with CCRs off your repeater.

[DonErle]

Not familiar with the term CCRs

[MozartMan]

Not familiar with the term CCRs

 

Cheap Chinese Radios.

[JLeikhim]

To be politically correct and technically accurate. I call them Low Parts Count radios.

 

What do you get for buying a $29.95 radio versus a $799.99 radio? Fewer parts.

 

Sent from my SM-T350 using Tapatalk

[WRAK968]

What are the advantages of having different squelch codes on the TX and RX side of a GMRS repeater? Is it more common than using the same code on each?

I owner two mixed code repeaters. There were two reasons for doing this. A ) Security. For a bit I had an unknown user keying the repeater for minutes at a time. After asking the user not to do this they chose to key the repeater for nearly 30 minutes. Of course the repeaters TOT tripped after 2 minutes, however the user continued to key either until they were bored, or until their radio finally killed itself, nearly 30 minutes and long enough for me to figure out where they were. So I changed only the input tone so the user couldn't trip the repeater (or its twin) again. B ) We kept the original output tone to make it seem like we never changed tones at all. Trying to "scan" the repeaters output would only give the 223 code for output. I figured this would frustrate anyone who is trying to get access without checking with me first.

[WRKC935]

Yes, split repeater tones will give a level of privacy to repeaters. Another option is the RAC code.  This was a thing back in the 90's that still exists occasionally in commercial radio.

The RAC or Repeater Access Code, was a data burst that the repeater was programmed to hear to go into transmit. It was also a Motorola thing.  I don't believe, but could be wrong, that only Motorola radios would generate a RAC.

To hear it on the air, it sounded like an MDC1200 burst.  Kenwood I believe used a DTMF version of this. 

 

I will say that running MDC1200 can be handy if you are having issues with folks squirreling on your repeater. 

If you run it and then comment about it not being on their signal, you can get them to enable it with and ID.

If you have the correct setup, or a radio that will do it, you can send a STUN command to that ID and turn his radio off.

While this will generate a LOT of hate and discontent, it's effective against morons that can't seem to understand what a private repeater is.

Of course, it's a mostly Motorola thing and you can't as far as I know STUN a CCR.  But I sure wish you could

[SkylinesSuck]

My KG-1000's mention stun and kill functions but I never knew what they did. Now I know.

 

Just curious WRAK968, how did you find the offender and did you knock on their door? I used to DF ELTs with Civil Air Patrol when I was younger, but I've never seen what equipment LMR guys would use for that.

[serrasalmus]

My KG-1000's mention stun and kill functions but I never knew what they did. Now I know.

 

Just curious WRAK968, how did you find the offender and did you knock on their door? I used to DF ELTs with Civil Air Patrol when I was younger, but I've never seen what equipment LMR guys would use for that.

i saw that in mine also and was hoping that it would work on anyone who touched the mic that wasnt spose to.....stun is a viable radio protection asset for kids like mine that want to say hi to everyone on the radio....even when ur not home....

also just think of the fun u could have with your brothers or sisters (at least once)..."hey bro go hop on the radio and give me a 3 count so i can listen to the other radio and see if i got it set up right in the car" .... "picks up mic, gets knocked the f down a peg" all the while your around the corner with a camera to video this and post it to a gmrs forum u visit...

[Lscott]

If you run it and then comment about it not being on their signal, you can get them to enable it with and ID.

If you have the correct setup, or a radio that will do it, you can send a STUN command to that ID and turn his radio off.

 

If the radio supports a STUN function but the user doesn’t have a code entered that won’t work. Of course you would have to know what that code was before hand, which if it’s an unknown user you won’t have it.

 

Changing input PL codes works for a very short time with a determined jammer. It only takes a few minutes curchunking the repeater using different analog PL tones until they hear the squelch tail. There are only around 38 to 40 of them. 

 

As far as using an output tone that isn’t that effective either. All my radios, CCR’s - Ham - commercial, there is a provision for entering a RX tone, which I never use. In that case I don’t even care if there is a tone on a repeater output, I’ll hear anything that’s there.

 

The purpose of STUN codes is to disable a lost or stolen radio that you own and programmed. On all of my radios I get used that’s one of the first things I make sure is cleared out. 

 

I would suggest using a digital tone, there are more of them. Also using an uncommon repeater access method, like MDC1200, might work out better. The later isn’t that common outside of Motorola radios. Only a few of my commercial Kenwood radios have it for example.

 

One other idea is to also use a non standard repeater split. There is nothing in the FCC rules that requires the repeater split to be exactly 5MHz. The requirements are one frequency from the 467.xxx input group be used and one from the repeater output group, 462.xxx, be used. Any radio that has preprogrammed repeater channel frequencies won’t be able to use the system setup using an odd spilt. In the Ham world I’ve run across a few odd repeater spilts so it’s been done there.

[WRAK968]

My KG-1000's mention stun and kill functions but I never knew what they did. Now I know.

 

Just curious WRAK968, how did you find the offender and did you knock on their door? I used to DF ELTs with Civil Air Patrol when I was younger, but I've never seen what equipment LMR guys would use for that.

Being a ham, I had limited experience with fox hunting. Fox hunting is the hobby's name of locating a transmitter. I took the information I had and moved forward. I could hear the signal in my house with an antenna on a portable in one direction so that burned off about 85% of the area needing checking. I removed the antenna and began driving around until a signal returned on the radio. This further reduces the area as a portable without an antenna will only pick up stronger signals. Holding the radio to my body blocks signals from one direction, and I turn until the signal sounds strongest. Doing that a few times and I ended up driving past the guys house while he was outside. Seeing a vehicle with warning lights and 3 antennas freaked him out cause he and his buddys ran inside and the transmission stopped soon after. I also noticed a few minutes later when I drove past again that the antenna on his car was gone.

 

I did not confront the person, that is not what self policing (which is what HAM and GMRS is) is about. You do the leg work, gather enough evidence, and forward it to the FCC who may do something if the interference can/has caused property damage, or if the incident presents a public safety hazard. Confronting someone this day in age is a good way to get your head blown off, or be posted on the news as racist, or some other crazy negative like that.

[DonErle]

Wow,

 

Thanks for all the info. My only repeater experience has been along the FrontRange of CO, where almost all repeaters require a split code and Texas (Dalhart to Austin) none required a split code. Of interest to me since I have a new Motorola MXT400 and was unable to input split codes until I purchased a cheap PC laptop, programing cable and loaded a copy of the software to make the changes. A bit of a pain, but glad I did all this just for the learning experience.

 

So again, thanks for all your help. Plus I learned about CCRs!

[serrasalmus]

Wow,

 

Thanks for all the info. My only repeater experience has been along the FrontRange of CO, where almost all repeaters require a split code and Texas (Dalhart to Austin) none required a split code. Of interest to me since I have a new Motorola MXT400 and was unable to input split codes until I purchased a cheap PC laptop, programing cable and loaded a copy of the software to make the changes. A bit of a pain, but glad I did all this just for the learning experience.

 

So again, thanks for all your help. Plus I learned about CCRs!

i think ive talked to you on the metro600 or leehill725

[DonErle]

i think ive talked to you on the metro600 or leehill725

We probably have talked on both. I live in SW Longmont so Lee Hill closer to me. My MXT400 resets the TX code to the same value as the RX code when I just touch the TC/DCS button. Even if touched accidentally. Pointed out to Midland and they tell me the design of the front control is such that it always sets TX and RX the same, that's why they provide the programing cable to change. They probably don't want to fix so there is a good market for their MXT500 that comes out later this year. . So I've been checking just to confirm I still have TX. Now I just lock the keypad to avoid issue. Also, I just download the radio occasionally using the PC and programing cable to make sure correct codes are still split. Will talk again I'm sure. Trying to improve my knowledge.

[serrasalmus]

awesome that was def u i member the location, im in loveland so both r a good reach for me i belive im 29 miles from the leehill725 and 37ish from the metro600, do u also use the gsharp there in longmont or is it dead? holler at me anytime u want i monitor all the front range repeaters even though i can only hit those 2, havent tried the metro 700 on the new radio

[DonErle]

Have not heard of gsharp repeater in Longmont. It's not on this site's map. Metro 700 is down right now, not sure when it will be back. I'm 11 miles from Lee Hill and 19 miles from Metro 600. You must live on a hill in Loveland if you can hit Metro 600 at 37 miles. See you on the air Works 790.