December 2004 - January 2005 hunts for 146.91 problems

Paging on 146.31. TOI. One of the freq's is 47.68mhz. Theory, Lebonon Mountain, Hancock. Heard at the Pittfield Airport.

Re-tranmission: Middleburg 146.61(123pl) re-transmitted on 146.31. Suspect un-identified link transmitter pointing towards Syracuse?

Kerchunker: No details here, call me at home or on 146.58.

More  details after the hunt is complete.

May 10-15, 2003 A Hunt for the 146.91 Interference

Some time in March we started hearing paging interference on 146.91. During the winter without access to Mt. Greylock the only thing we could do was guess at the source. I did a PC signal compare to several paging companies in the area and discovered 157.74 was the page we were hearing. I went to three of the 157.74 sites in our area and heard nothing on the 146.31 input frequency. So my guess was that maybe we had another case of third order intermod in the 146.91 front end like we had when 144.39 packet was interferring. We still could not get to Mt. Greylock to even try that theory so the problem just persisted. No way to prove anything until the mountain opened. Then on a weekday of the eneding May 3/4 Sigurd (KJ1K) and Ed (N1FGY) made a successful trip up greylock in a 4x4 pickup truck. They took out the pre-amp and the noise was still there! They also hooked an HT to the repeater antenna and found that they could hear the interference on the repeater input! So now the hunt was on! On May 10th Sigurd and I (Tim/KE3HT) went up greylock again and got some confusing bearings until we got on top of the mountain by the monument. We got a nice 55-60degree bearing from there. I used a three element tape measure beam (see our equipment page) and a home brew switched attenuator. I even combined them with body sheilding (the process of using your body as an additional reflector to narrow the beamwidth of the Back side of the beam) to get as narrow of a bearing we could. Sunday May 11th I drove out to Greenfield, MA in order to get another bearing. I just wanted to see if the direction was NH or Maine. I got two bearings  345 from the east site and 330 from the west site. These two did not intersect with each other. This meant that one or both of these readings was not to good. In any case the signal was Not in Maine. when you look at the Mt Greylock line and its intersection with these you could see the signal source was probably within in 10 miles of a town called Marlboro. It was probably a one day trip. I took Thursday off  and  Ed joined me to take a closer look at the source of the interference. Some of the many reports we had on the interference said they thought it was near Bennington so we took off along Rt 8 and stopped in Searsburg. We had  nothing to the west towards Bennington but we had a good signal towards the east at 80degrees. Looking at the map we now knew that our four lines all surrounded Marlboro. We picked a site that was the target of one of our Hounds hunts, it was called the HogBack Mountain. We figured we could have a nice clear line of sight signal. When we got there we discovered that we could not get a bearing! We were on top of it! Even with 96db of attenuators switched in and No antenna I could not tone down the signal. We did discover that as we drove away from the site with no antenna we could get the signal to drop off so we measured the distance away from the top we went on each side of the hill before the signal dropped off and found the top to be at the center of our measurements. We did see a couple of other towers on another hill top to the west of us on the Hogback shi area. So with the attenuator on 96db and no antenna we went towards the other towers and the signal dropped of. So we are pretty sure of the source of the 146.325 signal. Turns out this hill has a 157.74 transmitter on it!  This hunt took a few days of work but it was fun to use our skills to find a real interference signal. This information and maps were e-mailed to both Mt Tom and Mt Greylock repeater clubs presidents. The source: N42 51.230 by W72 47.684.
Click on these maps for larger versions.

Now that the location has been identified Sigurd aand Ed went to work on identifing the bad transmitter.
 Click here. There is some really good analysis of the signal at this link.

October 5th, Plane crashed 5:30am, found 16:30pm

Don (N1ISB) was called around 8:30am and was asked to see who might be available for a search and rescue mission involving a plane crash at 5:30am. At around 11am Don was calling us back and asking for us to make the trip to the Williamstown Fire department. Ed (N1FGY), myself Tim (KE3HT) and Don (N1ISB) all made it there and signed in. Three officers and three hams were the first search parties to start looking for the plane. The State police might have been looking to get a helicopter in there after the clouds cleared but after awhile it started to look like the day might stay overcast. Thats when the first foot search parties went in. We were escorted with sirens and lights by MASS state enviornmental police to a back road just east of Berlin mountian. Ed and I took our search gear and mounted  ATV's with two of the police officers. My portable 5 element beam was a bear to handle and still be able to hold on to the frame of the ATV. The  trip up the mountain only had a few obstacles to overcome. The first was a bridge out which required the ATV's to make a river crossing along some rocks then climb the other side of the river bank. What a neat ATV! I took the chicken way out and crossed on foot. We had a couple of trees in the logging trails to go around but we did not have to stop till we were facing a up hill slope that the ATV's could not climb. We were three teams but split up in the woods. Ed took the south ridge, I took the center ridge and a police officer with no df equipment took the north ridge. Ed heard a rise in the noise, which is trade mark in AM signals, to the north of him. I was to close to the shadow of my ridge to hear anything  but I confirmed the position of Ed and my police officer used his compass to figure out which way was north of Ed. The officer to our north went further north of us when he picked up the scent of Aero-fuel. That lead to the helicopters circling him and the plane was found. The police did not really want us on the scene but my officer (Sgt. Terry, id=S18) was very poilte and concerned for my safety. He really did want to help get us into a position to DF the plane. The State Police should be commended for such fine officers. The only thing that might have gone better if that we should have started earlier in the morning to hear the ELT (Emergency locator transmitter) before its battery ran down. The signal got weaker to the point of dissappearing by the time they actualy got to the plane. Ed only got one bearing on the signal and as he got closer to the ridge got closer to the shadow of the hill and of course lost the signal. You can view the news broadcast of the story from WNYT and see how things were interperted by the news crews. Nov 15, 1999 update: A nice thank you from a friend of one of the pilots of the plane. He also sent a set of pictures to be seen here.

September 26th, Greylock, lost day hikers at night !

We had a real hunt this evening as well. Right after the NOBARC club meeting N1FGY,KJ1K and KE3HT were up at Greylock looking at the split pipes on the tower when the call came in that there were lost hikers on the mountain. The hikers had Motorola FR50 radios. We had some trouble figuring out that channel 14 was 447.7125mhz. With good weather the hikers were able to signal a hellicopter with the exact location so our attempts at DFing them were not successful. I was totaly unprepared for the event. I also never heard that I should stand down from the hunt. I think the ground crews were successful in extracting the hikers but it was so late a night that the net control just stopped when they were done. I am not sure. I would like to be more prepared next time. Two areas of preperation are needed.
#1 We should be prepared to hunt for lost hikers or hunters that may have radio's even if they are not ham radio's.
#2 We should be prepared to hunt for people that interfere with the operation of any emergency event. There are $20,000 fines for emergency interference. In some cases there are also rewards to catch the jammers.
#1 We are looking at the idea of putting some of the more useful frequencies used by hikers and travelers up on this web site somewhere so we can get fast access to them should the need arise again in the future. When you see them posted, print them out and stick them with your ham gear. I also have a plastic carry all box that I keep my dop scan stuff in, I just added the list and a scanner so I can scan for out of ham band signals.
#2 Everybody likes to monitor the frequency when there is a real emergency. Many do not say anything unless they have something useful to say. Would you like to help without being to involved or leaving the house on a cold winter night? PLEASE when you hear a jammer on a real emergency event, CHECK THE INPUT, and report it on another repeater or simplex. You can do this without leaving your easy chair. For instance if a WX problem is going on on 146.91 try 449.426(-)(pl162.?), 147.03 or even 146.52. If I hear anything happening I plan on being out there with the dop scan and I need the help of everyone sitting at home. Please press the REV (reverse) or MONI (monitor) buttons available on almost every ham radio. If you hear the jammer, note the Signal level and call it in on one of the other frequencies.
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This page was last updated 20 January, 2002 20:45 -0500