Re: Topband: Operations...
On Thu, 2011-12-22 at 05:20 -0500, Jon Zaimes AA1K wrote: Since in Europe and Asia the band typically starts at 1810 kHz it's possible those RBN's don't scan below there. 73/Jon AA1K Hi Jon, I tried again this morning from 11:00 Z for a little more than 15 minutes. I have been sending a long string..up to 10 CQs and signing twice. I pause and tune a little up and down, sip my coffee, scratch the dog's ears, and go again. I have it that my part of the band for casual, non-DX ragchewing is that same bottom 10 kc of the band so that's where I am trying. I try to get between 1808 and 1809. I can get pretty close but I don't take amateur grade tuning dials too seriously - except the xtal calibrator that keeps me inside the band. I check that against WWV often. I believe this morning I was operating very close to 1808.5 kc but maybe it was only 1808.49213875 kc wink. QRN and broadcast crud was around S4 this morning so weaker signals would have been tough to dig out. I haven't been hearing very much activity in the mornings. I did hear some SSB further up the band and a W2 calling CQ for DX. I'm not DX for him so I kept quiet. I was on last night too but not until after our dinner party and it was almost 10 PM local time. Lots of hams in my small propagation radius were likely already in bed. I will probably try a little earlier in the evening when I can..maybe tonight. I'm rounding up parts for a Switching/patch panel so that I can change my antenna from it's series configuration on 160 to L for 80 and 40. It's cumbersome to make the change at the moment with lots of opportunities for errors (Murphy ya know). I need to be able to change that antenna more easily and also select different antenna and radio combinations. I have a different receiver that stands up much better to the broadcast band crud and I only need to make some wiring mods to accommodate T/R switching. Happy holiday season and Merry Christmas to all. I hope all of you are enjoying your families and friends during this multiple holiday season. 73, Bill KU8H ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Noise problem question
I have one of these units ... http://pw1.netcom.com/~t-rex/ ... A nifty device. I purchased the complete unit as a kit about 7 years ago for around $40 plus shipping. I have never seen him advertise the kit, I found out about that after I contacted him. The gentleman that produces this kit is also a ham, a KC7 in Nevada. I added a $14 radio shack speaker/amplifier for all to hear. I have not used it to find noise, when the rain stops I'll see how it does. I does have about a 150' to 200' detection range on the local bats depending as per my gain setting. 73, Mike WA5POK -Original Message- From: Tim Duffy K3LR Sent: Wednesday, December 21, 2011 8:38 PM To: 'Chet' ; 'Lee Ward' ; topband@contesting.com Subject: Re: Topband: Noise problem question Hi Chet: Just add a l to the end http://www.midnightscience.com/ultrasonics.html I own one of these units - it is great for finding power pole problems. 73, Tim K3LR -Original Message- From: topband-boun...@contesting.com [mailto:topband-boun...@contesting.com] On Behalf Of Chet Sent: Wednesday, December 21, 2011 8:01 PM To: 'Lee Ward'; topband@contesting.com Subject: Re: Topband: Noise problem question The link noted below does not work for me. I am using I E 8. I tried it 3 times. Please post a better one if you have one 73 Chet N4FX -Original Message- From: topband-boun...@contesting.com [mailto:topband-boun...@contesting.com] On Behalf Of Lee Ward Sent: Wednesday, December 21, 2011 8:27 PM To: topband@contesting.com Subject: Re: Topband: Noise problem question Phil, W0XI, has put a kit ultrasonic detector on the market. Well worth looking into. http://www.midnightscience.com/ultrasonics.htm 73, Lee, K0LW -Original Message- From: topband-boun...@contesting.com [mailto:topband-boun...@contesting.com] On Behalf Of W2PM Sent: Wednesday, December 21, 2011 4:04 PM To: John G3PQA Cc: David Raymond; topband@contesting.com; Jon Zaimes AA1K; W5UN Subject: Re: Topband: Noise problem question I have used one which the ARRL RF lab brought down here to address a very serious problem. We were able to identify the BOLT on the insulators where arcing was coming from, photograph it, attach both the audio file and the spectral display unique to each offender and the power company still reneged. Until FCC saw this and that was the end of the power company resistance. Problem fixed. Those devices are not easy to aim however. You need a steady hand and lots of patience. Sent from my iPhone ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Noise problem question
I'm not sure this would be useful as it seems not to be very directionally sharp. The ultrasonic device would be the last step in positively identifying the source of the arcing so it necessarily means it has to be extremely sharp. Less than 3 degree sense zone. You can get reasonable sharpness at 400 MHz AM with a 5 or 6 element handheld Yagi by the way but not sharp enough to point to actual source component up one the tower or pole. On high tension towers there are banks of insulators so the gapping noise is likely from one of those, not the whole bank. This is why you have to narrow it down. IF you're lucky and have an honest and competent power company they'll do it and just pointing them to a specific pole or tower is fine. They'd appreciate it (but make sure you get them all before calling them in!) A final note, based on my extensive working with ARRL on this topic it is clear the industry and FCC doesn't look at solving these things in weeks. Months minimally and often more than a year. FCC moves very very slowly and the office which handles this has been reassigned at time to other projects taking them off all amateur enforcement for months at a clip. That will only get worse with diminishing budgets. I Sent from my iPad On Dec 22, 2011, at 7:53, mikefur...@att.net wrote: I have one of these units ... http://pw1.netcom.com/~t-rex/ ... A nifty device. I purchased the complete unit as a kit about 7 years ago for around $40 plus shipping. I have never seen him advertise the kit, I found out about that after I contacted him. The gentleman that produces this kit is also a ham, a KC7 in Nevada. I added a $14 radio shack speaker/amplifier for all to hear. I have not used it to find noise, when the rain stops I'll see how it does. I does have about a 150' to 200' detection range on the local bats depending as per my gain setting. 73, Mike WA5POK -Original Message- From: Tim Duffy K3LR Sent: Wednesday, December 21, 2011 8:38 PM To: 'Chet' ; 'Lee Ward' ; topband@contesting.com Subject: Re: Topband: Noise problem question Hi Chet: Just add a l to the end http://www.midnightscience.com/ultrasonics.html I own one of these units - it is great for finding power pole problems. 73, Tim K3LR -Original Message- From: topband-boun...@contesting.com [mailto:topband-boun...@contesting.com] On Behalf Of Chet Sent: Wednesday, December 21, 2011 8:01 PM To: 'Lee Ward'; topband@contesting.com Subject: Re: Topband: Noise problem question The link noted below does not work for me. I am using I E 8. I tried it 3 times. Please post a better one if you have one 73 Chet N4FX -Original Message- From: topband-boun...@contesting.com [mailto:topband-boun...@contesting.com] On Behalf Of Lee Ward Sent: Wednesday, December 21, 2011 8:27 PM To: topband@contesting.com Subject: Re: Topband: Noise problem question Phil, W0XI, has put a kit ultrasonic detector on the market. Well worth looking into. http://www.midnightscience.com/ultrasonics.htm 73, Lee, K0LW -Original Message- From: topband-boun...@contesting.com [mailto:topband-boun...@contesting.com] On Behalf Of W2PM Sent: Wednesday, December 21, 2011 4:04 PM To: John G3PQA Cc: David Raymond; topband@contesting.com; Jon Zaimes AA1K; W5UN Subject: Re: Topband: Noise problem question I have used one which the ARRL RF lab brought down here to address a very serious problem. We were able to identify the BOLT on the insulators where arcing was coming from, photograph it, attach both the audio file and the spectral display unique to each offender and the power company still reneged. Until FCC saw this and that was the end of the power company resistance. Problem fixed. Those devices are not easy to aim however. You need a steady hand and lots of patience. Sent from my iPhone ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Topband: ZJ Beverage Box
I have one of these that I want to refurbish for use as an antenna-end preamp for a Beverage on Ground (BOG) RX antenna. I believe the MMIC amplifier in it is fried, but I do not have any documentation on the unit. Can anyone help? -- 73, Pete N4ZR The World Contest Station Database, updated daily at www.conteststations.com The Reverse Beacon Network at http://reversebeacon.net, blog at reversebeacon.blogspot.com, spots at telnet.reversebeacon.net, port 7000 AND now at arcluster.reversebeacon.net port 7000 ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: ZJ Beverage Box
Pete, all what I have regarding the ZJ bevs kits I posted on my blog here: http://topband.blog.cz/1011/zj-beverages-and-how-it-works-part-i http://topband.blog.cz/1011/zj-beverages-and-how-it-works-part-ii hope it helps, 73 - Petr, OK1RP On Thu, 22 Dec 2011 09:23:00 -0500, Pete Smith n...@contesting.com said: I have one of these that I want to refurbish for use as an antenna-end preamp for a Beverage on Ground (BOG) RX antenna. I believe the MMIC amplifier in it is fried, but I do not have any documentation on the unit. Can anyone help? -- 73, Pete N4ZR The World Contest Station Database, updated daily at www.conteststations.com The Reverse Beacon Network at http://reversebeacon.net, blog at reversebeacon.blogspot.com, spots at telnet.reversebeacon.net, port 7000 AND now at arcluster.reversebeacon.net port 7000 ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Noise problem question
John G3PQA wrote: For those who wish to build an ultrasonic detector (or in the absence of DX locate bats!) an article was published by ARRL in 2006http://www.arrl.org/files/file/Technology/PLN/Ultrasonic_Pinpointer.pdf I have built a couple of this design using the Far Circuits pcb and they work well, needs a small parabolic dish and piezo electric detector at its focal point. Also I should mention that Jerry K4SAV has designed some improvements in sensistivity and mixing if needed. This is a very useful device at pinpointing a problem. If the noise source is not very close to you, a radio of some kind will be needed to get somewhere close to the source. When in the area, a check of each power pole with the ultrasonic detector will usually locate the problem. In all cases I have been able to determine which item on the pole is the problem. It's amazing how quick the service can be when the power company doesn't have to do any work at locating the problem. In one case I called in a problem, telling them it's the surge suppressor on the top north corner of a specific pole. Two hours later the noise disappeared. I couldn't believe they fixed it in that time, I was thinking oh no it's gone intermittent, so I drove to the area and they had disconnected the surge suppressor. I also found it amazing at the distances that can be involved in these noise problems when the source is loud. The example above was 3 miles from my house and the noise level at my house was S9 (on 160 meters). I have identified two problems in that area, both of which were fixed, but the area continues to emit noise that I can hear. I'm sure there are more smaller problems there. When the source is that far away, if you just call the power company any complain, they will never find it. The only source that I never found using the ultrasonic detector turned out to be a plasma TV in a house about 1500 ft from my antenna. Fortunately they moved less than a year later. The biggest problem I have when using this is that when I start looking I usually find multiple noise sources. When at a considerable distance from home most of these sources are not audible and it's sometimes difficult to identify exactly which one is the one causing the problem. If the source has a particular characteristic then it's a piece of cake. Note: Don't get fooled by the bats and the grasshoppers at mating time. They don't really sound like noise, but more like a data channel. Jerry, K4SAV ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Topband Noise noise question (Mike Greenway)
Another good source for an ultrasonic (US) kit and a construction article is www.midnightscience.com, website of The Xtal Set Society. I built a receiver (about $150) on their instructions. It has been so successful our local very responsive power coop bought a $4500 commercial version. The power coop didn't make this investment out of gratitude for my discovery of numerous noise sources, although I did that with my combo IC706, VHF whip on the car, and US detector. They did it because they had a cost study done that concluded about 7% of their energy was going to ground via noisy leaks. Old infrastructure seems to be the primary culprit around here. The study prompted the employment of an engineer, an expensive receiver specifically intended to find leaks, and (after seeing mine in action) the US detector. Their commercial US detector is 30 times more expensive than my plumbers delight model, and perhaps twice more effective. Their receiver is a real asset. The noise engineer and I hook it to my antennas, note the pulse characteristics of the power leak, then are able to practically drive right to it. Some of the time anyway and given a pretty strong QRN signal. The bad news is no matter how successful I am new sources keep on coming on. Stuff breaks, the temperature varies, the wind blows, lightning strikes, the line crews over and under tighten hardware or install wrong, poles decay away and catch fire, birds fry - a never ending task. If anyone's interested in photos please email off the reflector k6xt at arrl dot net. -- 73 Art K6XT~~ near Allison Colorado Success is going from failure to failure without a loss of enthusiasm. ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: 1820 BCB
There have been some interesting developments and observations regarding my noise problem on 1836 that I had mentioned in a previous message. (See below.) First of all, I'd like to thank those folks who responded to my post with some excellent suggestions. I started to search in earnest for the source of the noise. Typically, I only tune 160M between 1815 and 1840 and use that range on my SDR-IQ panadapter. Today, I opened up the range and immediately saw an AM signal on 1840. I was able to make out the audio and identified two local AM stations: WGFC (1030 KHz) and WPIN (810 Khz). The first is a low power Mom and Pop station about eight miles away and the second is a Blue Grass and Gospel station about 15 miles away. Both are daytime stations and QRT at around 5 PM at this time of year. I contacted both stations and both were extremely agreeable and helpful. It turned out that the engineer at WPIN was a very knowledgeable ham who also worked 160M. He was able to control the 810 TX remotely, and while we were on the phone together, he turned it off. The AM signal on 1840 disappeared, but there was still a strong, narrow carrier. The carrier was also visible and equally strong on 1830, 1820, etc. After installing an RX 4-square last year, I had observed very low level signals every 10 Khz on 160M, but they were so weak that I ignored them. However, this season they were somewhat stronger and today, as the night progressed, they became extremely strong, comparable to W1AW's S9 signal at this QTH. Because the signals tonight were as strong as I'd ever heard them, I could detect some audio, but it was unintelligible. I also observed that the broad signal around 1836 was as strong as I'd ever seen it, and there was a similar, though weaker, signal centered around 1808.5 that I'd never seen before. I had to QRT because of other commitments, but I will pursue the problem further tomorrow. In view of Rick's comments and the WDOR problem on 1820 reported by Larry, I wanted to add my current experiences to the discussion. At this point, I'm convinced that the source of the problem is the 24 hour station and that the WPIN and WGFC signals are getting mixed somehow to produce the AM signal on 1840. 73, Joe K2XX / Regarding noise on 160M, I have been consistently observing all season long a broad signal, reminiscent of a plasma TV, centered around 1836 KHz. Since it seems to be on 24/7 and my closest neighbor is a half mile away, I don't think it's a TV. It's more or less centered on 1836 and is quite wobbly and varies in amplitude and frequency. It's about 2.5 KHz wide, and it doesn't vary in strength when I change directions on the RX array. / On 12/21/2011 2:44 PM, Rick Karlquist wrote: lrp...@comcast.net wrote: The BCB on 1820 has become considerably louder lately. The interference has been identified as WDOR www.wdor.com out of WI. As the audio is intelligible. I know of a couple of Emails that have been sent to the station. Maybe if more polite Emails are sent to the station corrective actions will be taken. Larry W8VVG ___ UR RST IS ... ... ..9 QSB QSB - hw? BK Intermods on even multiples of 10 kHz are simply a fact of life on 160 meters. Never operate exactly on one of these. In the recent Stew Perry, a station was absolutely zero beat at 1820. I was lucky to be able to copy him. He was probably wondering why it was so easy to hold that frequency. In the rest of the world, change 10 kHz to 9 kHz. Rick N6RK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1890 / Virus Database: 2109/4694 - Release Date: 12/21/11 ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: 1820 BCB
That is a VERY important point Joe. getting mixed somehow- often occurs without fault from either of the two mixed stations - but as a result of a nearby rectification area (the right metal hardware (rectifiers) coupled to a antenna of some sort with good primary RF energy from the stations) - that maybe located many miles from both stations - but breeds the mix. And that is what you hear on 160 and 80. Guys are fast to blame the AM radio stations (and some have problems) - when after a deeper dive - the stations spectral purity meets or exceeds the FCC regulations. I have found my share of AM station mixers - and it is not easy - they take on a non powered life of their own - just like the first crystal radio I built with a razor blade and pencil lead. My most recent mix at K3LR involved 3 AM stations. The closest one 1470 - had their 2nd harmonic added to the next stations primary frequency - result was booming signal (both audios) on 3.730 MHz. The 1470 2nd harmonic with the further station added together gave a - signal on 3.510 (both audios). Lots of DF to find the mixer. Which was one bad power pole ground (located close to station #1) was the problem. Ground fixed - everybody is happy. problems gone. 73, Tim K3LR -Original Message- From: topband-boun...@contesting.com [mailto:topband-boun...@contesting.com] On Behalf Of Joe Giacobello, K2XX Sent: Thursday, December 22, 2011 10:26 AM To: rich...@karlquist.com Cc: topband@contesting.com; lrp...@comcast.net Subject: Re: Topband: 1820 BCB At this point, I'm convinced that the source of the problem is the 24 hour station and that the WPIN and WGFC signals are getting mixed somehow to produce the AM signal on 1840. 73, Joe K2XX ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Noise problem question
The W1TRC unti is very, very sharp with the parabolic reflector. The one I saw mentioned earlier as a Bat detector kit does not appear that it would be directive enough but the W1TRC is super effective. The signature is very subtle and you have to be right on the bad component. I have compared it with the commercial Radar Engineer units that the power companies use and it is almost identical in pinpointing the defective part on the pole. Not that we have to do that but when you hear the arc signature on the pole you know you have the right one. I have had occasions when it would appear a pole was bad but no arc signature and it would turn out to be another pole adjacent. It is possible for the arc to be covered or on top when the unit cannot detect it but it has worked 100% for me. They power company uses a Ultrasonic unit that is on a pole where they can sniff around once on top of the pole. 73 Mike K4PI -Original Message- From: W2PM Sent: Thursday, December 22, 2011 8:37 AM To: mikefur...@att.net Cc: topband@contesting.com ; k...@k3lr.com ; Chet ; Lee Ward Subject: Re: Topband: Noise problem question I'm not sure this would be useful as it seems not to be very directionally sharp. The ultrasonic device would be the last step in positively identifying the source of the arcing so it necessarily means it has to be extremely sharp. Less than 3 degree sense zone. You can get reasonable sharpness at 400 MHz AM with a 5 or 6 element handheld Yagi by the way but not sharp enough to point to actual source component up one the tower or pole. On high tension towers there are banks of insulators so the gapping noise is likely from one of those, not the whole bank. This is why you have to narrow it down. IF you're lucky and have an honest and competent power company they'll do it and just pointing them to a specific pole or tower is fine. They'd appreciate it (but make sure you get them all before calling them in!) A final note, based on my extensive working with ARRL on this topic it is clear the industry and FCC doesn't look at solving these things in weeks. Months minimally and often more than a year. FCC moves very very slowly and the office which handles this has been reassigned at time to other projects taking them off all amateur enforcement for months at a clip. That will only get worse with diminishing budgets. I Sent from my iPad On Dec 22, 2011, at 7:53, mikefur...@att.net wrote: I have one of these units ... http://pw1.netcom.com/~t-rex/ ... A nifty device. I purchased the complete unit as a kit about 7 years ago for around $40 plus shipping. I have never seen him advertise the kit, I found out about that after I contacted him. The gentleman that produces this kit is also a ham, a KC7 in Nevada. I added a $14 radio shack speaker/amplifier for all to hear. I have not used it to find noise, when the rain stops I'll see how it does. I does have about a 150' to 200' detection range on the local bats depending as per my gain setting. 73, Mike WA5POK -Original Message- From: Tim Duffy K3LR Sent: Wednesday, December 21, 2011 8:38 PM To: 'Chet' ; 'Lee Ward' ; topband@contesting.com Subject: Re: Topband: Noise problem question Hi Chet: Just add a l to the end http://www.midnightscience.com/ultrasonics.html I own one of these units - it is great for finding power pole problems. 73, Tim K3LR -Original Message- From: topband-boun...@contesting.com [mailto:topband-boun...@contesting.com] On Behalf Of Chet Sent: Wednesday, December 21, 2011 8:01 PM To: 'Lee Ward'; topband@contesting.com Subject: Re: Topband: Noise problem question The link noted below does not work for me. I am using I E 8. I tried it 3 times. Please post a better one if you have one 73 Chet N4FX -Original Message- From: topband-boun...@contesting.com [mailto:topband-boun...@contesting.com] On Behalf Of Lee Ward Sent: Wednesday, December 21, 2011 8:27 PM To: topband@contesting.com Subject: Re: Topband: Noise problem question Phil, W0XI, has put a kit ultrasonic detector on the market. Well worth looking into. http://www.midnightscience.com/ultrasonics.htm 73, Lee, K0LW -Original Message- From: topband-boun...@contesting.com [mailto:topband-boun...@contesting.com] On Behalf Of W2PM Sent: Wednesday, December 21, 2011 4:04 PM To: John G3PQA Cc: David Raymond; topband@contesting.com; Jon Zaimes AA1K; W5UN Subject: Re: Topband: Noise problem question I have used one which the ARRL RF lab brought down here to address a very serious problem. We were able to identify the BOLT on the insulators where arcing was coming from, photograph it, attach both the audio file and the spectral display unique to each offender and the power company still reneged. Until FCC saw this and that was the end of the power company resistance. Problem fixed. Those devices are not easy to aim however.
Topband: 1820 BCB
This could be reduced ~30 dB by a shorted 1/4 wave stub on the TX output...~178.5' of 0.66 Vf coax and one T-connector. 73, Bill W4ZV ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Operations...
Hi, I've had several useful suggestions including moving a short way up the band. I already knew hams in other countries don't have the same frequency allocations we do. I was trying to stay out of the way for the DX chasers (and the DX). Maybe I just got some bad advice about that. I'm going to start using a little more range of motion in my wrist on that VFO. I have been staying below 1810. There were some comments about a too long string of CQs. I don't like long CQs, either but 6 to 10 isn't all that long (I've heard some that ran to 30 or 40 (or more)) and when the fish are scarce you have to move the bait more. I'm going back to my 3X2 and see if that helps. I am, however going to still sip my coffee and pet the dog between strings grin. 73, Bill KU8H ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Topband: Speaking of noise...
Here is my situation. I am pretty sure noise is from switching power supplies. Unfortunately, it tends to put noise right where I don't want it. Like bottom of 160, 80 and 40m. Typically the noise is 20-25 kHz of S8-9. One hears modulations on it and the whole band moves up and down in frequency 15-25 kHz over many hours. Best way to locate, inside house, outside house and correct? David J Rodman, MD Assistant Clinical Professor Department of Ophthalmology SUNY/Buffalo Office 716-857-8654 ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Speaking of noise...
David, I think the divide and conquer approach is the best. Hopefully the source(s) are in your own home, much easier to resolve. What I did was to connect a 12 volt battery to my K3 so I could listen without needing AC. Then shut off the main breaker to the house. The noise was gone (yay!) Then one at a time turned on each individual breaker until the noise started again. Then went around and unplugged everything one at a time on that circuit until the noise went away. I discovered I had two circuits with noise offenders. One was a Mikita battery charger for a battery powered drill in the garage. The second was a DirecTV receiver. It was the worst. Even though it was turned off it radiated noise because the power supply is on all the time. ( So it is best to unplug everything when testing !) I called DirecTV and they acknowledged that some of the receivers can have RFI issues. They sent me a new receiver in a few days and no more problem. I have tried doing sleuthing with a portable AM radio but it wasn't effective at all, the AC lines conduct and radiate the noise so it is hard to nail down. Hopes this helps and hope it is in your own home ! 73, Bob K6UJ On Dec 22, 2011, at 8:03 PM, D Rodman MD wrote: Here is my situation. I am pretty sure noise is from switching power supplies. Unfortunately, it tends to put noise right where I don't want it. Like bottom of 160, 80 and 40m. Typically the noise is 20-25 kHz of S8-9. One hears modulations on it and the whole band moves up and down in frequency 15-25 kHz over many hours. Best way to locate, inside house, outside house and correct? David J Rodman, MD Assistant Clinical Professor Department of Ophthalmology SUNY/Buffalo Office 716-857-8654 ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
