Need some advice

[AsstChief]

This sounds like a very intelligent crew so I thought I would ask you guys what you think. Keystone Fire Dept. is running a repeater on the VHF side. When we first had it we had someone transmitting on the same freq with the same PL tone. That was frustrating having them on the repeater. So I changed the tone and re-programmed all of our radios with the new tone and now it is happening again with someone different. What can I do to keep unwanted traffic off the repeater? Is there another way to program the repeater and radios with a more secure tone? If so how can I tell if my radios will accept that type of tone? I would appreciate any input here because I am just about to pull my hair out.

 

[KD5RJZ]

If you're dealing with an unlicensed user, your options are limited. Most newer radios come with a PL decode feature. That is, you can monitor the input side of your VHF repeater and the radio will tell you what PL tone you guys are using and from there it is rather simple to use the repeater. Your best option generally is to ignore them and they will usually get bored and go away.

 

[VA3CAF]

Emerg Services Interference Issue

I would think that, given that your dealing with an Emergency Service, the FCC should be the first to ask regarding any unauthorized activity on the repeater. In this part of the world, any interference to Emergency Services is regarded as top priority and it doesn't take inspectors too long to zero in on unauthorized transmitters.
I thought too that they (the FCC) issued specific CTCSS and PL tones with the licence, so wondering if you had asked your district office before doing any tones changes?

 

[KD5RJZ]

The probability that the FCC would get anything done is low. A lot of times we have pirates on the Ham VHF repeaters in the area (Tulsa), and when a ham comes back "I'm licensed to use this frequency, etc etc etc the FCC is going to track you down..." The pirate just stays longer knowing he upset someone. When you ignore them or come back with something along the lines of "Unidentified Station, I believe your CB is malfunctioning, move to a different location in your trailer park and try again", they usually get offended and leave.

 

[dstew67]

yeah, usually ignoring them is the most effective thing. At first, it will probably confuse them, and make them think they are getting through. Then, they'll probably assume you have some super-duper filter on your radios that eliminates their interference. They'll get bored and move on.

 

[freqscout]

Chief- I don't know what your radio setup is, but you can try doing a Digital Code Squelch(DCS) instead of a PL tone. Not all radios are capable of this so again it depends on what you have. If it is truly an accidental interference, this would probably eliminate it. Not as many agencies use DCS as do PL.
If you do not have this ability I would spring for a PL Tone that is further to the edges of the PL frequencies, especially the higher end. It seems that most PL users remain in the middle of the PL frequencies and lower in the OKC Metro, dunno how true this is for rural though.
These are only solutions that are usable if the interference is indeed accidental. I know that skip coming in causes problems here in the metro on our VHF system quite regularly so I would not be surprised if this is the case for you.
If the interference is purposeful you can contact the FCC and file a complaint but I would not be surprised if they are slow in responding because they have several complaints to take care of and not enough people.
The other thing that you can look into is trying to find the source. If you can, work with your local PD or SO too. You might be able to see if it fits the criteria for a city or state citation for interfering like you would use if there was someone interfering with a police investigation, firefight, or fire investigation on scene.

 

[AsstChief]

I contacted the FCC and they advised me they do not give out PL tones. He advised me to just pick one and plug it in. I also have filled out two complaints about this person and have not heard back from the FCC. Those complaints were filed several months ago. This lady gets on there and is talking to someone else but we can't here the other party. She talks about all kinds of stuff as if she was on a ham freq. This is on the 155 range and I don't believe she should be doing that.

 

[VA3CAF]

Emerg Svc Interference

Well, unfortunately it sounds as though your Federal agency (FCC) is at the same plateau as ours in Canada. The cut backs and restraints are being felt throughout the communication sector but, here they do take pretty swift action to protect the emergency services and aero frequencies.
Failing action from the FCC maybe you could touch with your local Ham Radio Club and ascertain as to whether they are set up for 'Fox Hunts'. They might enjoy the challenge of sniffing out your interference problem for you. Hopefully you have someone in your area with the smarts to figure out what the problem is, as to whether it's a birdie from a legal system or just what is happening.

 

[dbestfirefighter]

Locate an active ham group locally, most usally one or two of the hams have DF (direction finding) equipment. Have them locate the source and let your PD do a "come to jesus meeting" with the persons. Lets us know if we can help out most of us on this OK forum site are hams.

 

[mancow]

What type of equipment are you using? If it's all fairly current Motorola stuff you may be able to set it up with MDC required access.

 

[KD5RJZ]

It could also be somebody using old Business band gear in the 155Mhz range.

There are several hams in Tulsa with doppler gear, let me know if we can do anything to help you out. kd5rjz@tulsahamradio.org

 

[car2back]

uh oh.... it won't be long now..... someones gonna get busted!

 

[OkRob]

Doesn't APCO still do the frequency coordination for the fire service frequencies? I'm not sure as I haven't applied to coordinate one in quite a long time, but if the depts are using the proper coordination it should prevent them from interfering with each other except in rare occasions like band openings. One of those interfering with your system may not be coordinated properly, in which case you may be able to get some help from APCO on it.

Rob

 

[car2back]

I am confused... Asstchief, is it interference from a legit (liscenced) radio user or someone intentionally (or unintentionally, but illegaly) causing the interference?

 

[OkRob]

Asstchief, check here for more info: http://www.apcointl.org/frequency/

Rob

 

[2112]

Doesn't APCO still do the frequency coordination for the fire service frequencies? Rob

Acutally, I think IMSA does fire service for frequencies below 512 MHz. In either case, you can check here for the appropriate coordinator and their contact info:

http://wireless.fcc.gov/publicsafety/coord.html

Also, be real careful about some of those "official" looking notices that you might get in the mail from various organizations that claim that your license(s) are in danger of cancellation or expiring. Most of these are just companies who have accessed the public-record license holder information available online and sent letters hoping to "scare" license holders into using their expensive services unnecessarily.

 

[dstew67]

...This lady gets on there and is talking to someone else but we can't here the other party. She talks about all kinds of stuff as if she was on a ham freq. This is on the 155 range and I don't believe she should be doing that....

Doesn't sound like a coordination issue to me. Sounds like unauthorized use.

 

[OkRob]

Doesn't sound like a coordination issue to me. Sounds like unauthorized use.

Indeed it does. For some reason, when I saw that part of the AsstChiefs post, it didn't register in my brain for some reason. I'll plead too many birthdays.

I wasn't aware that IMSA was doing the fire service coordination either. It's probably been over 15 years since I did paperwork for a fire service coordination.

Hope you get some relief soon AsstChief. I know how annoying that can be for sure.

Rob

 

[fast2okc]

155.295MHz

Keystone Fire Dept. is running a repeater on the VHF side. When we first had it we had someone transmitting on the same freq with the same PL tone. That was frustrating having them on the repeater. So I changed the tone and re-programmed all of our radios with the new tone and now it is happening again with someone different.

Chief, looking at the licensed users for your input frequency of 155.295MHz, there are several that could be the problem.

There is KVP513, which is the Hospital in Bristow.

There is KVT891 which is the Hospital in Stillwater.

There is WPYN399 which is the Bartlesville Ambulance.

155.295MH is also a frequncy that has been around for medical use for a long time and as such, there may be some additional users that have expired licenses. Even if you could find a PL that keeps these outsiders off your repeater, they may still cause some interference. And there is never a good time for communication interference.

My suggestion would be to request a new frequency from the FCC. Yes, it's crowded out there, but there are a lot of freqeuncies opening up in the VHF business bands, because many of those users are moving to UHF trunked systems, NexTels or Cell Phones. Perhaps whoever does your radio work could help.

Good Luck,

fast2okc

 

[dstew67]

Nice work fast2okc! I had thought about the input, but didn't take the time to look it up because it sounded like an unauthorized user. If it's a hospital, then there's no telling what they would be talking about, just due to being untrained.

Cheif, you said that you heard a woman talking, but didn't mention hearing the other side of the conversation. If that's the case, what fast2okc is suggesting would explain that. If the lady you heard is on a base radio with an antenna up on a small tower, or on the roof of the hospital, and the other party is in a mobile, you'd likely hear her, but not the other party.

Sounds like requesting another frequency may be the way to go...