Subj: Interference Tracker Responses Date: Mon, Apr 17, 1995 10:19 AM CDT From: HBXH55A@prodigy.com X-From: HBXH55A@prodigy.com (JIM WILSON) To: dx@unbc.edu Thanks very much to all who responded with suggestions for interference tracking devices/methods. The responses were so numerous (many said they were also looking for such a device) I decided to post this summary of the responses: The majority of the replies indicated that portable am radios work well in many cases, especially where electrical power lines are the problem. Here are a few specific suggestions that I thought might be of particular interest: -------------- I use a portable Sony ICF-SW7600G. There are other choices. Getting direction info is difficult but just using the s-meter can be sufficient as you move around. Good luck. Dennis, W1UF See: A Line-Noise Sniffer That Works in QST Sept., 1992. Also see a follow up in Tech Correspondence, QST April, 1994. 73 de N4OO abowen@freenet.scri.fsu.edu -------------- From: Gary M Danaher There was a device called the Easy Finder whose sepcs have been published in the mags several times. It was designed to listen for a null in the vhf bands, but I would think tat with a longer antenna, it would work on hf as well. The principal is that it receiveds a signal through 2 different antennas, in the case of vhf, a pair of bow ties, mounted on either side of the board. Since the signals hit the radio at different moments in time, there is a squeel in the audio. You turn the device until it is head on and the squeel disappears. It has no front to back distinguishing though, so you have to plot a heading based on two or more locations. Works great on 2 meters and ought to work on lower frequencies as well. Cost about 15 bucks with all the bells and whistles from radio shack. Good luck. ------------------- One good receiver for this would be one of those marine radios with a built-in rotatable antenna. Heath made one several years ago which even had a "sense" antenna to help reduce the bidirectional ambiguity. Heath is long gone, but you might get lucky at a used marine gear dealer. I've never seen one at a hamfest, but who knows? You would be limited to the marine band, but that's probably not a disadvantage. One difficulty to keep in mind is that when you're having a problem with RF coupled into AC lines, the source is no longer a point (easily locatable). The wiring becomes the antenna, so when you get close, your DF'er will point every which way. Good luck. 73, Bill W7LZP ------------------- When I was KL7HGR, I had really bad electrical interference in Fairbanks. I tried to get the power company to use some locator to find it and kill it. It was S9+10 on most bands when it would hit. They didn't have anything. I ended up using an old Hallicrafters shortwave portable radio that had a good loopstick antenna for broadcast and VLF. It was directional enough to pinpoint the source to one of two power poles...they fixed the noise when the finally sent someone to follow me down the street with the radio "zazzing" away, DFing the noise. Maybe this will help you with the problem. 73 and good luck, Larry, W7DGP -------------------- I really appreciated all the suggestions. I think I will start with the Sony shortwave portable radio with the S-meter and see if I can find the culprit. 73, Jim - W4MWT