RE: [Repeater-Builder] OT: 155.190 intereferes with Ham Radio Frequencies
Mathew, After looking at the number of transmitters operated by the Fulton County Sheriff and the Rochester Police Department, I can see that there are a number of possibilities. For example, when you double the Rochester PD channel at 155.130 MHz and then subtract the nearby NOAA Weather Radio Station WXK74 at 162.475 MHz, you get a third-order IM product at 147.305 MHz- only 20 kHz away from your 2m repeater's output. An Amateur-grade radio might be loose enough to pick that up. That's why I asked about whether a commercial-grade radio received the same interference. My gut feeling is that there is a third-order IM product that involves one of the police or sheriff frequencies, and the mixing may be occurring in a transmitter that does not belong to Fulton County or the City of Rochester. I believe that the best way to determine what carriers are causing the interference is to set up a spectrum analyzer where the interference is very strong, and monitor the spectrum to see what carriers are always present when the interference occurs. Since the sheriff uses UHF control stations, you might also monitor that band for clues. Steady carriers used by broadcast station STL (studio-to-transmitter link) or remote-monitoring equipment often are on the air 24/7 and can be just dead carriers most of the time. High-power paging transmitters are also IM candidates. I'd collect a lot more data before contacting anyone on the law-enforcement side. Use accurate equipment to determine exactly which frequencies are key to the interference. Some of the channels are very few kHz apart, so you need to be able to identify each frequency. When the time comes to make contact with the agency involved, don't call the chief! Look up the point of contact for the station licensee in the FCC license database. For Fulton County license KSB609, it's the Communications Director at 574-223-2910. Just call and ask for the Radio Shop. Tact and diplomacy goes a long way here, especially since you are offering to help clear up a little problem that may cause interference to their radio system. 73, Eric Lemmon WB6FLY YAHOO! GROUPS LINKS Visit your group "Repeater-Builder" on the web. To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
Re: [Repeater-Builder] OT: 155.190 intereferes with Ham Radio Frequencies
You are right Gary, the last thing I want to do is get a police cheif upset with the ham community, especially if it caused by something other than their transmitter. Mathew Gary <[EMAIL PROTECTED]> wrote: Assuming the amateurs are hearing this traffic with their radios incarrier squelch here's a few suggestions:assuming there is regular activity on the commercial channel attempt to'hunt' the signal on the amateur freq, try to verify an increase insignal strength and perhaps audio clarity as you approach the commercialtransmitter site.if possible look for a 147.2Mhz spur on the commercial transmitter'soutput. Look at the duplexer, transmitter, circulator, every point alongthe way. If you encounter something then inform the owner but try toavoid confrontation.If you encounter resistance from the owner, the 'chief' or his peoplethen I would suggest backing off, gather as much data withoutinteracting with them then pass the data on to your local FCC rep andtheir Spectrum Enforcement Division directly. Others may have betterideas for your region.Garyn9lv wrote:> I've have been asked to assist with an issue in a town about 40> miles from here regarding a commercial system that is causing> interference with Ham Radio.>> At best, the information that I have thus far, is that there is a> repeater that is owned by the county sheriff's department, this> repeater itself is on the output of 155.190, and is said to not be> causing interference. The only time that it interferes with the> hams in the area is when the city talks on the repeater for 911> dispatches. At this time I do not know how much power or what type> of radio they are using, antenna height, or brands.>> The radios thus far that is recieving the interference, from two> locations, one about a mile away and the other about a block away,> is the IC-2100H mobile radios, and an ADI AT600 handi talkie. There> has been other complaints, I'm supposed to get additional> information this weekend, and possibly make a trip up there to hear> the interfernce.>> Questions I have is, what should I be looking for? What avenue's> should be taken. I do know that the Chief has been notified of the> situation, but refuses to see a problem and has done nothing to> rectify the situation.>> At this point, I do know they say that on the receive of 147.285> that there is noted a nearly full scale signal, making it impossible> to hear the repeater that is about 25 miles north of there, of which> is on a 400 ft tower, classified as a large scale repeater.>> Thanks> Mathew>>> Yahoo! Groups LinksYahoo! Groups Links<*> To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/<*> To unsubscribe from this group, send an email to:[EMAIL PROTECTED]<*> Your use of Yahoo! Groups is subject to:http://docs.yahoo.com/info/terms/ Yahoo! Mail goes everywhere you do. Get it on your phone. YAHOO! GROUPS LINKS Visit your group "Repeater-Builder" on the web. To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
Re: [Repeater-Builder] OT: 155.190 intereferes with Ham Radio Frequencies
Assuming the amateurs are hearing this traffic with their radios in carrier squelch here's a few suggestions: assuming there is regular activity on the commercial channel attempt to 'hunt' the signal on the amateur freq, try to verify an increase in signal strength and perhaps audio clarity as you approach the commercial transmitter site. if possible look for a 147.2Mhz spur on the commercial transmitter's output. Look at the duplexer, transmitter, circulator, every point along the way. If you encounter something then inform the owner but try to avoid confrontation. If you encounter resistance from the owner, the 'chief' or his people then I would suggest backing off, gather as much data without interacting with them then pass the data on to your local FCC rep and their Spectrum Enforcement Division directly. Others may have better ideas for your region. Gary n9lv wrote: > I've have been asked to assist with an issue in a town about 40 > miles from here regarding a commercial system that is causing > interference with Ham Radio. > > At best, the information that I have thus far, is that there is a > repeater that is owned by the county sheriff's department, this > repeater itself is on the output of 155.190, and is said to not be > causing interference. The only time that it interferes with the > hams in the area is when the city talks on the repeater for 911 > dispatches. At this time I do not know how much power or what type > of radio they are using, antenna height, or brands. > > The radios thus far that is recieving the interference, from two > locations, one about a mile away and the other about a block away, > is the IC-2100H mobile radios, and an ADI AT600 handi talkie. There > has been other complaints, I'm supposed to get additional > information this weekend, and possibly make a trip up there to hear > the interfernce. > > Questions I have is, what should I be looking for? What avenue's > should be taken. I do know that the Chief has been notified of the > situation, but refuses to see a problem and has done nothing to > rectify the situation. > > At this point, I do know they say that on the receive of 147.285 > that there is noted a nearly full scale signal, making it impossible > to hear the repeater that is about 25 miles north of there, of which > is on a 400 ft tower, classified as a large scale repeater. > > Thanks > Mathew > > > Yahoo! Groups Links > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
RE: [Repeater-Builder] OT: 155.190 intereferes with Ham Radio Frequencies
I tried to find a licensed user of 155.190 MHz in an area 40 miles north ofyour QTH, around Michigan City, but found none. Fulton County Sheriff's Department, Rochester, Indiana Rochester Police Department, this is the department that can be heard. I also couldn't find a coordinated repeater on 147.285 MHz in that area. Please identify by callsign the repeater on 147.285, and where it is located. I simply assumed that "here" refers to your QTH. Are there any other transmitters at that location? K9WZ Repeater in Plymouth, Indiana He aslo mentioned that he could hear them on 146.535 Mhz, they operate there on simplex. Can you identify what Sheriff Department is using 155.190 MHz,and where it is located? I ask these questions because I suspect that theSheriff's signal may be mixing with a third carrier and that station may begenerating IM, unbeknownst to the Sheriff. This third station may verylikely be at the same site as the Sheriff's repeater, and I can look at suchcandidates only if I know where each site is located. It may be veryinstructive to set up a spectrum analyzer to see what signals are presentwhen the interference occurs.At this point, I do not know where the actual repeater is located in their county. I'm assuming from what he explains that it is there in Rochester, as that is the main city for the county. Some questions come to mind:1. Is the signal from the Sheriff repeater being heard by the complainers'radios directly, or is the Sheriff's signal being repeated over the 147.285machine? The only time they hear the repeater, and from what was explained, they can hear them very clearly, is when the city of Rochester talks on the repeater. 2. If the Sheriff's signal is being repeated on the 2m machine, whathappens when the repeater transmitter is shut off? That is, can you stillhear the Sheriff's signal on the 2m repeater's monitor speaker at the site,with the TX off? At this point I have not contacted Wayne, K9WZ whom is the owner of the 147.295 repeater. Wanted to do some research before I get in touch with anyone, to make sure we don't make enemies. I do know they told me they are hearing it on more than one frequency in the two meter band. 3. Is the interference also heard over a commercial-grade radio? Thismight eliminate an image reception issue. At this point I have to say no. I will be taking a number of radios with me when I visit the location this Saturday. 4. What are the details about the 2m repeater? (Make/model of receiver,transmitter, duplexer, filters, antenna, etc.) This I would have to contact Wayne to get this information. If you have access to IRLP, I do know he has IRLP and Echolink access, however I do not know either of his nodes. 5. When the interference is heard, is it a mixture of voices or tones, oris just the Sheriff dispatcher heard clearly? They stated they can hear them clearly, however until I hear it for myself, I can't say what is actually being heard. Thanks! Mathew 73, Eric Lemmon WB6FLY-Original Message-From: Repeater-Builder@yahoogroups.com[mailto:[EMAIL PROTECTED] On Behalf Of n9lvSent: Tuesday, May 02, 2006 8:22 PMTo: Repeater-Builder@yahoogroups.comSubject: [Repeater-Builder] OT: 155.190 intereferes with Ham RadioFrequenciesI've have been asked to assist with an issue in a town about 40 miles from here regarding a commercial system that is causing interference with Ham Radio. At best, the information that I have thus far, is that there is a repeater that is owned by the county sheriff's department, this repeater itself is on the output of 155.190, and is said to not be causing interference. The only time that it interferes with the hams in the area is when the city talks on the repeater for 911 dispatches. At this time I do not know how much power or what type of radio they are using, antenna height, or brands.The radios thus far that is receiving the interference, from two locations, one about a mile away and the other about a block away, is the IC-2100H mobile radios, and an ADI AT600 handi talkie. There has been other complaints, I'm supposed to get additional information this weekend, and possibly make a trip up there to hear the interference.Questions I have is, what should I be looking for? What avenues should be taken? I do know that the Chief has been notified of the situation, but refuses to see a problem and has done nothing to rectify the situation. At this point, I do know they say that on the receive of 147.285 that there is noted a nearly full scale signal, making it impossible to hear the repeater that is about 25 miles north of there, of which is on a 400 ft tower, classified as a large scale repeater.ThanksMathewYahoo! Groups LinksYahoo! Groups Links<*> To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/<*> To unsubscribe from this group, send an email to:[EMAIL PROTECTED]<*> Your use of Yahoo! Groups is subject to:http:
Re: [Repeater-Builder] OT: 155.190 intereferes with Ham Radio Frequencies
The local oscillator. It can travel for miles. Joe M. Tony VE6MVP wrote: > > At 08:35 PM 2006/05/02 -0700, you wrote: > > >Search for scanners that are tuned to receive 155.19, Seems to be a > >popular problem out here. Dead give away is when they scan a periodic > >pop can be heard on the channel you are trying to recieve. > > So how can a scanner interfere with a repeater? I'm probably missing > something basic but thought I'd ask anyhow. > > Tony Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] OT: 155.190 intereferes with Ham Radio Frequencies
At 08:35 PM 2006/05/02 -0700, you wrote: >Search for scanners that are tuned to receive 155.19, Seems to be a >popular problem out here. Dead give away is when they scan a periodic >pop can be heard on the channel you are trying to recieve. So how can a scanner interfere with a repeater? I'm probably missing something basic but thought I'd ask anyhow. Tony Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
RE: [Repeater-Builder] OT: 155.190 intereferes with Ham Radio Frequencies
-Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of n9lv Sent: Tuesday, May 02, 2006 10:22 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] OT: 155.190 intereferes with Ham Radio Frequencies I've have been asked to assist with an issue in a town about 40 miles from here regarding a commercial system that is causing interference with Ham Radio. At best, the information that I have thus far, is that there is a repeater that is owned by the county sheriff's department, this repeater itself is on the output of 155.190, and is said to not be causing interference. The only time that it interferes with the hams in the area is when the city talks on the repeater for 911 dispatches. At this time I do not know how much power or what type of radio they are using, antenna height, or brands. Mathew I think the problem might be with the city dispatching thru the repeater using a high power base. They could possibly be using the input of 153.875 and causing a local mix within the local radio's if. 155.19 output of repeater 153.875 input to repeater. Difference of 2.315 MHz??!? I hope this helps Wayne Wa9ne Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
RE: [Repeater-Builder] OT: 155.190 intereferes with Ham Radio Frequencies
Mathew, I tried to find a licensed user of 155.190 MHz in an area 40 miles north of your QTH, around Michigan City, but found none. I also couldn't find a coordinated repeater on 147.285 MHz in that area. Please identify by callsign the repeater on 147.285, and where it is located. I simply assumed that "here" refers to your QTH. Are there any other transmitters at that location? Can you identify what Sheriff Department is using 155.190 MHz, and where it is located? I ask these questions because I suspect that the Sheriff's signal may be mixing with a third carrier and that station may be generating IM, unbeknownst to the Sheriff. This third station may very likely be at the same site as the Sheriff's repeater, and I can look at such candidates only if I know where each site is located. It may be very instructive to set up a spectrum analyzer to see what signals are present when the interference occurs. Some questions come to mind: 1. Is the signal from the Sheriff repeater being heard by the complainers' radios directly, or is the Sheriff's signal being repeated over the 147.285 machine? 2. If the Sheriff's signal is being repeated on the 2m machine, what happens when the repeater transmitter is shut off? That is, can you still hear the Sheriff's signal on the 2m repeater's monitor speaker at the site, with the TX off? 3. Is the interference also heard over a commercial-grade radio? This might eliminate an image reception issue. 4. What are the details about the 2m repeater? (Make/model of receiver, transmitter, duplexer, filters, antenna, etc.) 5. When the interference is heard, is it a mixture of voices or tones, or is just the Sheriff dispatcher heard clearly? 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of n9lv Sent: Tuesday, May 02, 2006 8:22 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] OT: 155.190 intereferes with Ham Radio Frequencies I've have been asked to assist with an issue in a town about 40 miles from here regarding a commercial system that is causing interference with Ham Radio. At best, the information that I have thus far, is that there is a repeater that is owned by the county sheriff's department, this repeater itself is on the output of 155.190, and is said to not be causing interference. The only time that it interferes with the hams in the area is when the city talks on the repeater for 911 dispatches. At this time I do not know how much power or what type of radio they are using, antenna height, or brands. The radios thus far that is receiving the interference, from two locations, one about a mile away and the other about a block away, is the IC-2100H mobile radios, and an ADI AT600 handi talkie. There has been other complaints, I'm supposed to get additional information this weekend, and possibly make a trip up there to hear the interference. Questions I have is, what should I be looking for? What avenues should be taken? I do know that the Chief has been notified of the situation, but refuses to see a problem and has done nothing to rectify the situation. At this point, I do know they say that on the receive of 147.285 that there is noted a nearly full scale signal, making it impossible to hear the repeater that is about 25 miles north of there, of which is on a 400 ft tower, classified as a large scale repeater. Thanks Mathew Yahoo! Groups Links Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] OT: 155.190 intereferes with Ham Radio Frequencies
On Wed, 3 May 2006, n9lv wrote: > At this point, I do know they say that on the receive of 147.285 that > there is noted a nearly full scale signal, making it impossible to hear > the repeater that is about 25 miles north of there, of which is on a 400 > ft tower, classified as a large scale repeater. Start looking for mixing products as well -- make sure that your repeater is protected with a circulator. The Chief may not have one. If all else fails, get the FCC involved and "wake them up" as the case may be. A lot of people don't realize when the FCC says jump, they mean jump. Nextel just got a reminder of this when the FCC made a visit and requested the transmitter be turned off for a quick test -- to the tune of $7K. -- Kris Kirby, KE4AHR <[EMAIL PROTECTED]> "BIG BROTHER IS WATCHING YOU!" This message brought to you by the US Department of Homeland Security Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] OT: 155.190 intereferes with Ham Radio Frequencies
Search for scanners that are tuned to receive 155.19, Seems to be a popular problem out here. Dead give away is when they scan a periodic pop can be heard on the channel you are trying to recieve. On 5/2/06, n9lv <[EMAIL PROTECTED]> wrote: > I've have been asked to assist with an issue in a town about 40 > miles from here regarding a commercial system that is causing > interference with Ham Radio. > > At best, the information that I have thus far, is that there is a > repeater that is owned by the county sheriff's department, this > repeater itself is on the output of 155.190, and is said to not be > causing interference. The only time that it interferes with the > hams in the area is when the city talks on the repeater for 911 > dispatches. At this time I do not know how much power or what type > of radio they are using, antenna height, or brands. > > The radios thus far that is recieving the interference, from two > locations, one about a mile away and the other about a block away, > is the IC-2100H mobile radios, and an ADI AT600 handi talkie. There > has been other complaints, I'm supposed to get additional > information this weekend, and possibly make a trip up there to hear > the interfernce. > > Questions I have is, what should I be looking for? What avenue's > should be taken. I do know that the Chief has been notified of the > situation, but refuses to see a problem and has done nothing to > rectify the situation. > > At this point, I do know they say that on the receive of 147.285 > that there is noted a nearly full scale signal, making it impossible > to hear the repeater that is about 25 miles north of there, of which > is on a 400 ft tower, classified as a large scale repeater. > > Thanks > Mathew > > > > > > > > > > Yahoo! Groups Links > > > > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/