Bob, Thank you very much for sharing all that. I like your dipole approach there, getting at least one end up in the air at the roof level of that condo. I could possibly do something like that, slingshot a line to the rooftop of this apt bldg somehow ... Maybe with some kind of batman grapple hook thing on the end that can snag on something hi. My big concern here is how close the power lines are. Anyway. I am still mulling it over and continue to work with the buddistick (or the metal downspout on this bldg which tunes up surprisingly well on all bands).
Mostly I am just trying to keep the faith right now that something will work out here. There is a lot of background noise here...tuning across the bands I hear one weird "signal" after the other, swooshing in and out as i tune the bands, which must be the horrid interference thrown out from all the WiFi routers around here... 60 cycle noise, buzzes, pops, I mean it is a real cacophony of sounds. There must be all kinds of intermodulation sorts of interference, the rfi mixing with the kx3's receiver. The NB and NR of the kx3 actually does a good job knocking a lot of that back. So far not one contact though. Trying *not* to see my investment as a rather expensive mini boat anchor. I think I will buy some China HT and at least get on 2 meters (not sure I am ready to spend the $260 on a 2 meter module for the kx3 just yet, although I will probably add it at some point anyway.) I wish there was some way to at least scare up some local 10 meter (line of sight) activity here so that I could at determine if this radio is transmitting okay. Some local HF qso's would be great... But I am not a part of a local ham club or anything here to try and set up a sked with anyone. Anyway... I appreciate your thoughts there, I am still trying to figure out what I really hope to get out of ham radio. So far it is QSOs on this Elecraft mailing list :) which is a great group here... This band is always open as long as the internet works. :) 73s, mike. On Aug 13, 2017 7:18 PM, "Bob McGraw K4TAX" <rmcg...@blomand.net> wrote: > Mike: > > Glad to share my thoughts and experiences. > > As to using a dipole, feed it in the center with coax RG-58, RG-8X. And > the dipole does not have to be in a straight line. On the balcony or > patio, a single center support and droop the ends down in an inverted V > style. Or stretch it out as straight as you can between two supports and > droop the ends if it is longer than the two supports are spaced. > > I used both of these combinations when we lived in a condo in South FL. > With one of my antennas I had it vertical by dropping a Dacron fishing > line from the roof of a 3 story building down to our balcony on the 2nd > floor. I moved it away, sideways from the balcony so as not to attract the > attention the upstairs neighbor. Connected the end of my 20 M dipole and > hauled it up such that the feed point was about at the ceiling level of our > balcony or the floor level of the upstairs neighbor. The other end made it > just about to the ground. A nice fishing weight attached to the lower end > kept thing taught. I used some #30 Teflon covered wire which was white. > Looked more like a spider web and couldn't be seen from 15 ft or so against > the white building. I just tied a knot in the end and attached the > Dacron. The center insulator was a piece of plastic from a milk jug, and > the #30 wire was not stripped but just tied with a couple of 1" or so > pigtails. Strip the ends and attach the coax. Found some white marine > RG58 for the feed line. It was in place for about 6 years. No one noticed > or said anything. Worked great. Fortunately our condo was only 30 units > most of which were seasonal occupancy. Thus empty most of the year. Only > about 12 to 15 full time residents. > > Just be creative. The site I refer to is that of DJ0IP. He designs > antennas for portable operation, back pack operation and such. Thus small, > compact and lightweight. He also has great information on > baluns........good ones........and bad ones. Correct applications and > incorrect applications. > > Yes, digital modes are very conducive to low power and noise conditions. > The new FT8 mode which is included in the WSJT-X latest version is fast and > good. Not a rag chew mode by any means, but one can make contacts with > the simple exchange of calls, grid squares, signal reports, 73 and log > it. Lots of activity on that mode. Much faster, actually 4 times, than > JT-65 which is more like watching paint dry. I've been active on 6M the > past 2 weeks on FT-8 mode and this weekend with the Perseid meteor shower > using MSK144. > > If you are trying to work the lower frequencies, below 7 MHz, you will > really need a much larger antenna. Not saying it can't be done but more > antenna and more power is generally required. For a while I use my > mobile HF Hustler antenna and a pair of vice grip pliers to clamp the > insulated base to the rail around the balcony. Worked OK but I was also > running 100 watts. > > Good luck, let me know if I can assist. > > 73 > > Bob, K4TAX > > K3S s/n 10163 > > On 8/13/2017 8:13 PM, Mike Parkes wrote: > > Hi Bob > Thank you for your detailed reply! As for radials, I am just using the one > radial that came in the kit. It has to be tuned for each band. My setup has > to be taken down and set up each time so a lot of radials could be an issue. > > I like your 20 MTR dipole thought. I have always had good results with > wires. I could possibly string up a 20m dipole. > > The digital modes are great I used to work a lot of that, and getting back > on those modes could help with weak signal work. > > And your points on the attenuation and backing off rf gain are great. I > was totally unaware of how that could help with noise on the bands. > Thanks again, excellent help > 73 > mike > > On Aug 11, 2017 10:04 AM, "Bob McGraw K4TAX" <rmcg...@blomand.net> wrote: > >> Mike: >> >> Comments in general..........the bands aren't in the best of conditions. >> Summertime makes for static crashes being created some 500+ miles away on >> 40 meters. And living in the midst of other apartments and power lines >> doesn't help. Then to make matters seemingly worse, a vertical seems more >> prone to pick up noise as noise is largely a vertical component. >> >> As to the vertical, my experience with verticals is that they do require >> a significant ground radial system in order to reduce the radiation loss. >> This is even after "tuning" for a low SWR. And your "mighty" amount of >> power doesn't help your cause either. HI HI. I'd try a simple coax fed >> dipole for say 20M which shouldn't be to difficult to get in the air a few >> feet there at the apartment. I operated from a ground floor condo unit >> for a few years. The new digital modes are a dream for weak signals both >> TX and RX. I'm really enjoying WSJT-X and the new FT-8 mode. >> >> As to the receiver in the KX3, it is darn good. However, noise on >> frequency can not be removed by any filtering. It just stomps on the >> receiver and its AGC. As a suggestion, use the attenuator and/or back >> the RF Gain down. Based on work of Rob Sherwood and others, optimum >> receiver performance is attained when the receiver noise floor is some 10 >> dB to 15 dB below band noise. Since we can't actually change the receiver >> noise floor, we can bring the signals and noise down close to the receiver >> noise floor with the internal attenuator and RF Gain. Most hams run too >> much RF gain thinking it is necessary to hear weak signals. More gain = >> more noise. Law of Physics.......with a few exceptions usually not >> available to hams. Think absolute zero and super cooled semiconductors. >> >> To do the math, if the KX3 noise floor is -125 dBm and the band is at -97 >> dBm or S-5 the difference is 28 dB. Accounting for having the receiver >> noise floor 10 dB below the signal, this says the receiver should have a >> combination of 18 dB attenuation and RF Gain reduction thereby bringing the >> signal + noise to about -115 dBm. >> >> Hope this helps. >> >> >> On 8/11/2017 11:33 AM, Mike Parkes wrote: >> >>> Okay I am reaching our to the Elecraft enthusiasts here for some feedback >>> if anyone cares to chime in. >>> I am just getting back on the air after years away from the hobby, so I >>> am >>> not that familiar with band conditions in general. It looks like the >>> sunspot cycle is heading for the cellar (if it isn't already there). >>> >>> Recently bought a KX3 and a Buddistick vertical (like, 2 weeks ago). Love >>> the KX3 it is a great radio... however... so far my efforts to hear much >>> of >>> anything, much less make a contact with someone, has been frustrating to >>> say the least. I live in an apartment and am surrounded by power lines >>> for >>> one thing. The background noise level on 40 is pretty bad varies but is >>> s7-9 mostly. I took my setup to a nearby park and the bands were >>> definitely quieter. So the local manmade noise level is an issue (and one >>> reason I chose the KX3 was the hope that its rcvr and filtering could >>> help >>> with that.) >>> >>> Have yet to make a single contact, so I am just wondering if I just >>> happened to choose a really lousy period of solar conditions for HF? Or >>> is >>> the base loaded vertical a joke? >>> >>> I would love to be able to find another ham even close by just to try and >>> get some sort of an HF QSO even if it is with someone down the block. >>> ...I can tune down to the AM broadcast band and was able to hear some >>> local >>> AM stations. :) >>> >>> Mike AB7RU >>> >>> (On a side note the tuner in the KX3 is great!. That thing was able to >>> get >>> a match for 80 meters on the Buddistick which was showing something like >>> 25:1 swr. The KX3 tuner clicked and rattled for a while and found a match >>> to <2:1. Not sure how much actual RF is going out, probably not much... >>> but >>> I was amazed it could tune to that high an SWR.) >>> ______________________________________________________________ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>> Help: http://mailman.qth.net/mmfaq.htm >>> Post: mailto:Elecraft@mailman.qth.net >>> >>> This list hosted by: http://www.qsl.net >>> Please help support this email list: http://www.qsl.net/donate.html >>> Message delivered to rmcg...@blomand.net >>> >>> >> >> > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
