Topband: carbon fiber
Thinking of carbon fiber for your next 160 meter project? Listed are material advantages & disadvantages. http://www.protechcomposites.com/pages/About-Carbon-Fiber.html 73 Bruce-K1FZ www.qsl.net/k1fz/beveragenotes.html _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: How much ground independence?
I use a reduced size flag (50%) antenna about 7 feet above the ground mounted on our deck right above our pool (comes down in the summer so we can swim) and I use a KB-5 for the feed line transformer. I rotate this antenna with a TV rotor. It sits about 20 feet from the house and about 50 feet from the transmit antenna. I have not tried any other height above ground simple because where I have the flag mounted is the best location I can find on my lot. This year I added remote variable termination with a photo cell and white LED. I see no difference in F/B with the variable termination on any band except when the resistance goes above 1500 then the F/B nears zero. Most of the time I leave it at 800-1000 and F/B seems to be a consistent 25db in most directions. I really have no other equipment to accurately measure F/B besides the S meter on my TS590 and a signal source from WWV. I live on an urban lot with lots of noise from various sources and the flag is almost always much more quite than my transmit antenna. I tried very hard to decouple the feed line, rotor line and LED feed line prior to entering the shack. I don't find that this antenna nulls the local big signals (1000 miles and in) very much and I always appreciate when a DX station operates split. I also use a Pixel loop. They both do well to null out local noise but sometimes the flag hears better and sometimes the Pixel loop hears better. I should add that on top band and 80 meters with the flag I use the DXE RPA-1 preamp. 73, Tony - K8ALM _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Wideband interference
The noise occurs early AM, before sunrise. It was gone during the day and early evening yesterday. I made a new recording this morning and the rhythmic nature of the noise pulsation is very evident: http://youtu.be/A0a1fLCHr9M 73, Barry N1EU On Thu, Dec 12, 2013 at 6:06 AM, Barry N1EU wrote: > Sorry for yet another plea for help identifying an interference source. > Please see the video/audio I just uploaded to http://youtu.be/AN9VNCanEJM > > The panadapter clearly shows wideband rhythmic interference centered on > the 160M band. The interference is predominant in the northeast Beverage > and also audible on the inverted L. There's audio in the recording for cw > and AM. > > Is this consistent with a faulty high pressure street light? > > Thanks & 73, > Barry N1EU > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Wideband interference
The on-off timing may suggest a timer applying power to a power leaking hot water heater. 73 Bruce-K1FZ - Original Message - From: "Barry N1EU" To: "topBand List" Sent: Friday, December 13, 2013 10:49 AM Subject: Re: Topband: Wideband interference The noise occurs early AM, before sunrise. It was gone during the day and early evening yesterday. I made a new recording this morning and the rhythmic nature of the noise pulsation is very evident: http://youtu.be/A0a1fLCHr9M 73, Barry N1EU _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Wideband interference
On 12/13/2013 7:49 AM, Barry N1EU wrote: The noise occurs early AM, before sunrise. The consensus among RFI professionals who hang out on the RFI list is that recordings and spectrum plots are not usually helpful, but walking around with a portable RX is. 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Wideband interference
I've had many helpful private emails from folks who've seen/listened to what I posted. An RFI occurrence may or may not have a characteristic fingerprint, but you're not going to know unless you ask around or search the Web for a similar recording. If someone posted a recording of interference similar to what I've personally identified in the past, I could certainly respond with my past findings and potentially help them. In any event, this is the first step I choose to take before heading out the door in the dark and bitter cold weather to snoop around the surrounding area. But thanks for your encouraging finger pointing to do just that. Barry N1EU On Fri, Dec 13, 2013 at 12:12 PM, Jim Brown wrote: > On 12/13/2013 7:49 AM, Barry N1EU wrote: > >> The noise occurs early AM, before sunrise. >> > > The consensus among RFI professionals who hang out on the RFI list is that > recordings and spectrum plots are not usually helpful, but walking around > with a portable RX is. > > 73, Jim K9YC > > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Wideband interference
I may be overreaching here but…in learning some of the new features of my K3/P3 with SVGA card and remote terminal I came across the screen snap or hold feature. If that image can be exported to the Utility program (or ???), saved, and maybe printed would it be possible to go portable and hunt for a similar noise signature? The reason I ask is that the local utility company owns a Radar Engineers receiver. They came to my shack, hooked up to my antennas and took a noise signature on the oscilloscope, and went hunting. They soon found the offending signal and fixed. Might be worth a try if one has a K3/P3 and the feature I describe does work. I’ve not tried it yet. 73, Gary NL7Y > I've had many helpful private emails from folks who've seen/listened to > what I posted. An RFI occurrence may or may not have a characteristic > fingerprint, but you're not going to know unless you ask around or search > the Web for a similar recording. If someone posted a recording of > interference similar to what I've personally identified in the past, I > could certainly respond with my past findings and potentially help them. > > In any event, this is the first step I choose to take before heading out > the door in the dark and bitter cold weather to snoop around the > surrounding area. But thanks for your encouraging finger pointing to do > just that. > > Barry N1EU > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Wideband interference
This sounds like it could be an appliance or light on either a timer or a photocell that is tied to daylight/night hours. Jim, KR9U -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim Brown Sent: Friday, December 13, 2013 12:13 PM To: topband@contesting.com Subject: Re: Topband: Wideband interference On 12/13/2013 7:49 AM, Barry N1EU wrote: > The noise occurs early AM, before sunrise. The consensus among RFI professionals who hang out on the RFI list is that recordings and spectrum plots are not usually helpful, but walking around with a portable RX is. 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Wideband interference
I think Jim and Barry both have valid points. Let me attempt to throw some perspective on it. For a ham faced with going out in the bitter cold to hunt down RFI, getting input and advice from others who have found the source of noise with similar sound or spectrum plots can help narrow down the likely source and save time in the field. There's certainly nothing wrong with that. On the other hand, if a ham approaches a professional working for a utility company (or whatever) about their RFI and says they believe it is coming from such and such a device based on the sound and spectrum plots, it may have a detrimental affect on the professional's estimate of the ham's approach and claims. It may affect their response to the problem. This isn't always going to be the case, of course, but it certainly can't hurt if the ham has already done some footwork to identify the source in a manner consistent with how it is done in professional circles. You want to make the best first impression you possibly can. The other issue that often comes up with hams is not having the portable equipment to track down a source, and budget concerns related to acquiring it. As a ham on a fixed income and extremely tight budget, I get this. I also get that there will be some reading this who are thinking I've got no clue whatsoever what a tight budget is. :-) That was me for many years. When I really started looking into cleaning up my RF environment, I realized the DF equipment had to be a priority, even though it meant downsizing my ham station and/or not replacing some gear that is badly outdated or on it last legs. I now consider the DF and RFI hunting equipment to be vital tools for survival in the modern RF jungle. I am personally experiencing a strong topband RFI issue that I haven't gone out to find. It will require a three mile walk with the relatively heavy and bulky DF equipment just to get to the likely source area, some walking to find it, and a three mile walk home after! In Maine that is brutal this time of year. On the other hand, even if I become 95% certain I knew what it is, I won't be calling a utility or other business/professional to report my RFI until I have been out to DF it myself. First impressions can be everything. This is just my opinion, of course. 73 -- Paul Kelley, N1BUG RFI Committee chair, Piscataquis Amateur Radio Club http://www.k1pq.org _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Wideband interference
I've had many helpful private emails from folks who've seen/listened to what I posted. An RFI occurrence may or may not have a characteristic fingerprint, but you're not going to know unless you ask around or search the Web for a similar recording. If someone posted a recording of interference similar to what I've personally identified in the past, I could certainly respond with my past findings and potentially help them. That's correct. Some signatures are easily identifiable as a source type. Some are not. If I were to guess, probably well over half are identifiable by characteristics as a likely source type. That still leaves many that are not. You have to put yourself in an open frame of mind and consider everything. Electric fences are easy as a group and type. Power lines are easy as a group and general type. Fish tanks or other things with thermostats are easy as a group containing thermostats. Switching power supplies are easy as a broad group. Your noise appears to be on where people might be up and around, rather than on like clockwork as a certain outdoor light level. I'd rule an outdoor light out right away based on the times and the changing tone. It does not appear to be laundry or cooking related, based on time, duration, and changing sound. It does not appear to be home indoor light related because it is not steady sound when on. It doesn't cycle off and on with a period like a thermostat, so that rules out many things. It doesn't sound like a battery charger. The noise I listened to did NOT appear to be periodic in change, but a randomly changing frequency pitch for variable periods. This potentially indicates a load changing on something randomly over short periods, something used when people are likely to be up, but off when they are gone or doing something else. TV sets and video systems change supply loads like that, and fit the pattern. It might be something else, but lots of things can be ruled out based on the sound. For me, it does help to have some idea what it might NOT be. That way I can drive past things I know it absolutely cannot be. Whatever it is, as Jim suggested, you will eventually have to DF it and then walk or drive that direction and find it. That is what ultimately matters. 73, Tom _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Well, Duh... (Apology re: ARRL160)
I screwed up and spent a couple of one hour stretches Saturday night CQing in the DX window until someone got my attention and convinced me that ARRL still had a DX window in their 160 contest, even though the CQ 160 and both all-band DX tests had dumped theirs years ago, and I thought I remembered ARRL HQ group voted to drop it from their 160 as well. [1] ** But no excuses for not knowing the rules.** So that makes my entry invalid, and will be submitted this year only as a check log. My entry will not have an invalid advantage over anyone else's. Apologies to anyone I may have inconvenienced. 73, Guy K2AV [1] Actually June, 2009, yes they did vote to drop it, and it was the ARRL Contest Advisory Committee. See: http://www.arrl.org/files/file/About%20ARRL/Committee%20Reports/July/29_Contest_Advisory_Committee.pdf An interesting read. Should note that the report phrases the current rule as a "recommendation", as if to indicate they don't consider it a hard rule, and *nobody* voted to make it a "requirement". They consider the rule unenforceable. From the report: "4. Vote: Rule 6.1 A. Delete (9) B. Make it a requirement (0) C. Leave it as a recommendation (7)" The report lists in their committee discussion many of the issues brought up in a thread on the DX window on TopBand a week or so ago. _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Well, Duh... (Apology re: ARRL160)
Hi Guy, I do not know if I was in the window. I was not looking as I too thought there was no Longer a DX window any more. 73 Chet moore N4FX -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Guy Olinger K2AV Sent: Friday, December 13, 2013 7:53 PM To: TopBand List Subject: Topband: Well, Duh... (Apology re: ARRL160) I screwed up and spent a couple of one hour stretches Saturday night CQing in the DX window until someone got my attention and convinced me that ARRL still had a DX window in their 160 contest, even though the CQ 160 and both all-band DX tests had dumped theirs years ago, and I thought I remembered ARRL HQ group voted to drop it from their 160 as well. [1] ** But no excuses for not knowing the rules.** So that makes my entry invalid, and will be submitted this year only as a check log. My entry will not have an invalid advantage over anyone else's. Apologies to anyone I may have inconvenienced. 73, Guy K2AV [1] Actually June, 2009, yes they did vote to drop it, and it was the ARRL Contest Advisory Committee. See: http://www.arrl.org/files/file/About%20ARRL/Committee%20Reports/July/29_Cont est_Advisory_Committee.pdf An interesting read. Should note that the report phrases the current rule as a "recommendation", as if to indicate they don't consider it a hard rule, and *nobody* voted to make it a "requirement". They consider the rule unenforceable. From the report: "4. Vote: Rule 6.1 A. Delete (9) B. Make it a requirement (0) C. Leave it as a recommendation (7)" The report lists in their committee discussion many of the issues brought up in a thread on the DX window on TopBand a week or so ago. _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Well, Duh... (Apology re: ARRL160)
I suspect "no DX window" is a fairly common perception. If you search the 160 rules on the string "dx window", you don't get a hit. Searching on "1.830" finds the text. It's listed under "Miscellaneous". You have to read it end-to-end to run into it. I also wonder what happened to the CAC's recommendation. I can't find any followup searching the ARRL site. 73, Guy. On Fri, Dec 13, 2013 at 8:03 PM, chetmoore wrote: > Hi Guy, > > I do not know if I was in the window. I was not looking as I too thought > there was no > Longer a DX window any more. > > 73 > > Chet moore N4FX > > -Original Message- > From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Guy > Olinger K2AV > Sent: Friday, December 13, 2013 7:53 PM > To: TopBand List > Subject: Topband: Well, Duh... (Apology re: ARRL160) > > I screwed up and spent a couple of one hour stretches Saturday night CQing > in the DX window until someone got my attention and convinced me that ARRL > still had a DX window in their 160 contest, even though the CQ 160 and both > all-band DX tests had dumped theirs years ago, and I thought I remembered > ARRL HQ group voted to drop it from their 160 as well. [1] > > ** But no excuses for not knowing the rules.** So that makes my entry > invalid, and will be submitted this year only as a check log. My entry will > not have an invalid advantage over anyone else's. Apologies to anyone I may > have inconvenienced. > > 73, Guy K2AV > > [1] Actually June, 2009, yes they did vote to drop it, and it was the ARRL > Contest Advisory Committee. See: > > > > http://www.arrl.org/files/file/About%20ARRL/Committee%20Reports/July/29_Cont > est_Advisory_Committee.pdf > > An interesting read. > > Should note that the report phrases the current rule as a "recommendation", > as if to indicate they don't consider it a hard rule, and *nobody* voted to > make it a "requirement". They consider the rule unenforceable. From the > report: > > "4. Vote: Rule 6.1 > A. Delete (9) > B. Make it a requirement (0) > C. Leave it as a recommendation (7)" > > The report lists in their committee discussion many of the issues brought > up > in a thread on the DX window on TopBand a week or so ago. > _ > Topband Reflector Archives - http://www.contesting.com/_topband > > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Well, Duh... (Apology re: ARRL160)
On 12/13/2013 08:03 PM, chetmoore wrote: Hi Guy, I do not know if I was in the window. I was not looking as I too thought there was no Longer a DX window any more. 73 Chet moore N4FX Hi, There have been several discussions about "windows" (not software) right here on the list. I'm pretty new to top band and the info about windows is conflicted and vague. Some might be outdated or whatever. For my own operation I will avoid getting in the way if I hear a DX pileup or DXpedition. Unless of course I am trying to work the pileup. Even if I can't hear the DX I'll know where he is because of the one or two transmitting on his frequency. I'm usually more interested in ragchews and making mutual QRM for a DX hunt in progress won't make any of us happy. As far as what the contest calls for as a DX window - well I can never keep them sorted out so I read through the rules each time. Otherwise I would always be doing something that doesn't fit. Every time I read the rules for a contest or sprint I have already been in I get surprised by details I had forgotten. I'm hardly even on the air right now anyway as I have to rebuild most of my ancient gear. Just a couple of thoughts that might help. 73, Bill KU8H Sent by smoke signals from a firepit in my back yard and keyed with a mylar "Space Blanket" _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Insulator problems
The Tx antenna I have been using very successfully for the last 8+ years, is a top-fed vertical. This feed arrangement requires the yagi used for top loading to be insulated from the mast. I have been using a nylon insert between the two halves of the stub mast as my insulator. This morning I noticed high SWR, firstly only on high power, but then at any power level. Today I brought the mast down for inspection, and the only sign of trouble I can see is in the insulator, which has bubbled visibly. This may (or may not) be the problem, but I propose to change the insulator even if only to eliminate it as the culprit. I have a couple of questions for this group. 1) Does anyone know if I can upload a jpg file to contesting.com, so that guys can see what I am talking about? Tree, I guess I can't attach a photo to a post to the group? 2) I always thought that nylon was a pretty good dielectric, and did not expect problems, especially at 1.8 MHz. The gap in the insulator is 7.5mm, or about 0.3". I estimate that there will be around 2 kV across this gap. Is nylon perhaps not as good as I thought it was? 3) If I replace the nylon with Teflon, will I lose anything in mechanical strength? Unfortunately this problem means that I will not be able to enter the Stew. We are going away for a week for the festive season, next weekend, so won't have time to fix the issue. Comments welcome. 73, Greg, ZL3IX _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Well, Duh... (Apology re: ARRL160)
This entire discussion strikes me as comical. I can recall several quite extensive discussions about the DX Window, and most of them have come to a consensus that that the DX window on topband was dead and buried. I haven't bothered to check the archives, but if I did, I'll bet that I've find that at least some of those speaking out so strongly in favor it it now said exactly the opposite back then. Another comical point -- everything written at HQ seems to be handed down from on high as chiseled into stone. How else to explain a rule for this contest that flies in the face of the CAC's recommendations from four years ago? Or does it mean that nothing that members say matters, and that nothing can ever change. 73, Jim K9YC On 12/13/2013 4:52 PM, Guy Olinger K2AV wrote: [1] Actually June, 2009, yes they did vote to drop it, and it was the ARRL Contest Advisory Committee. See: http://www.arrl.org/files/file/About%20ARRL/Committee%20Reports/July/29_Contest_Advisory_Committee.pdf An interesting read. Should note that the report phrases the current rule as a "recommendation", as if to indicate they don't consider it a hard rule, and*nobody* voted to make it a "requirement". They consider the rule unenforceable. From the report: "4. Vote: Rule 6.1 A. Delete (9) B. Make it a requirement (0) C. Leave it as a recommendation (7)" _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: K3 & some interesting noise lessons in the ARRL 160.
This may be specific to a K3 and no joy for other rigs. But there might be parallels elsewhere. Definitely YMMV. Usually in a 160 contest I try and get a run frequency down around 1815-20. For some reason in my locality that range is, and for a long time has been, a general garbage minimum in the noise floor around here, sometimes 2-3 dB better, so there is no incentive to CQ elsewhere. I have not had a problem establishing down around 1815-20, even when running 100 watts. But this year, off and on since late summer, and of course without any rhyme or reason or published schedule, I have had a really bad intermittent power line style buzz that was S7 to ten over S9, depending on only heaven knows what. I have not had any luck localizing it, largely because of it's variable and erratic nature. A lot of the time it has irregularly separated fast bursts, almost like it's trying to send Morse with its buzz. On the first night of the ARRL 160 contest, buzz was entirely absent. And I actually had the ARRL 160 weekend clear of family conflict for the first time in recent memory. Oh Joy! By the end of the first night I already had a personal best for the contest. The second night the noise struck half way through with a solid buzz. Ten over S9 in my usual hangout 1815-20-ish. A little less noise up higher but still covering all but the louder signals. No real help using my newly repaired and pattern-verified NE RX antenna. Loud there, too. Earlier work had ruled out a source in my or neighbor's houses. No quickie fixies. I was unable to hear anything except the louder signals, which I had pretty well worked out the previous day. Forget operating. So I decided to experiment with the noise mitigation methods/settings on the K3. Usually in these buzz circumstances, you can't find a persistent weak signal on 160 far enough into the noise to let you experiment with noise mitigation settings based on signal to noise. You wind up using the reduced noise level as the only clue for settings. Reduced noise level method is fine if you are working strong signals and you just don't want to hear the noise. But to pull out weak signals what you really need is to restore signal to noise separation all the way down to the weak signals. It turns out best signal-to-noise and best level-of-noise do not always generate the same weak signal readability. Some methods/settings reduce noise well but also trash the weak signals in the process. But being the contest, 160 was *loaded* with weak signals to test with. So I spent a few hours experimenting with K3 settings on weak signals, optimizing for S/N. Came up with NB only (no NR) DSP T1-7 + IF NAR4 using "250" 8 pole filter, which clearly gave the best separation between weak signal and noise, without the usual weak signal obliteration from traditional noise blanking in a contest. Usually the buzz gating the NB will add a 180 Hz raspy modulation (center carrier and +180, -180), an irritating buzzy noise, and can mush the wanted signal. Narrowing the CW width to 250 or 200 Hz (+/- 100 Hz) cleans off both the modulation (3 x 60 Hz), and signal-covering "hashy fuzz" caused by the irregular shape of the buzz waveform. After the determination of those settings, I scanned the band with those settings in NB. I discovered a narrow "null" in the noise or sweet spot between 1831 and 1833, sounding almost normal, with clear rendition of weak signals, which was up to 2 s-units better than the NB improvement in the least effective spots, which included my normal hangout of 1815-20. Don't ask me how that works, because I haven't a clue. 1831.5 was unoccupied, as was 1832.5 in a later stretch, where operating with the blanking on, it was as if the noise was not there at all. (See an earlier post about my unfortunate adventure with the DX window rule.) That narrow sweet spot in the blanked noise was still there Tuesday, at 1830-1832. With the noise back solid, and using the NB settings above, Tuesday night I was hearing LZ2DF on 1832 clearly, at what I would call 559 or 549. He was not hearing me running 1.5 kW, so this was clearly a normal state of affairs, controlling noise was on his end, not mine, even though the buzz was full on. Wednesday the buzz was there with separated bursts, but not quite so loud, and the aforementioned NB settings killed it at least semi-decently across the band. Go figure. I was able to clearly pull out way-down birdies and such, simply not there without the NB. Thursday the noise-blanking sweet spot was at 1.838, and a little broader than during the contest. The RX antenna clearly hears a weak birdie at 1.838 much stronger than on the TX. Yes, Virginia, the RX antenna has been working correctly the whole time. Today the buzz is gone at my noon-time opportunity for driving around and trying again to locate it with my K2. Tonight the buzz is back, mostly steady. The sweet spot is at 1.828 tonight. We will be renewing the search for the noise when it decid
Re: Topband: Insulator problems - attempt at attachment
_ Topband Reflector Archives - http://www.contesting.com/_topband
