Topband: Antenna Switch isolation capacitor
Hi All, A friend on 160 has had a problem with a Heathkit remote antenna switch due to a partial failure of the isolation capacitor in the remote unit. It is a .02 uF 1.6 KV disc ceramic that isolates the DC from the antennas. Since this results in about 4.4 ohms of XC - capacitive reactance in series with the 160 TX antenna, I was wondering if it would it be worth while to substitute a .05 uF disc ceramic to reduce the capacitive reactance (XC) to under 2 ohms on 160 meters? Thanks any info. 73, George, K8GG _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: 30-Foot Vertical
Hi All, I agree with Dave, If one can get 20 feet of mast out the top of the 30 foot tower and some top loading wires to bring resonance to where one desires in the 160 meter band then I would insulate the base and series feed it. It would be only about 3 db below a full size vertical over the same radial system and earth ground below. Feed point impedance will be between 12 and 25 ohms depending on ground losses, assuming at least 2000 feet of radials on ground, or decent elevated radials on a roof. GL 73, George, K8GG > During my 1988-1989 stint as J52US in Guinea-Bissau and 1990-1991 stay > as 9L1US, I made loads of QSO's in pile-ups and contests with a modified > Butternut HF-2V.?? I bought larger tubing for the top section and moved > the top-loading wires higher.?? The antenna then worked well on 160 and > 80 and was not resonant on 40m.?? In both places the antenna was high--on > top of a five story building with radials running on the roof and > running down several stories to warehouse roof in Guinea-Bissau and on > the flat roof of a three story apartment building atop one of the > highest hills overlooking Freetown in Sierra Leone.?? In both places I > had a tri-bander on several sections of tower on the roofs as well. > > I made contacts from Helsinki in the mid-1980's with the same antenna > (stock) but without as much success and again in the mid-1990's with it > modified per the African variant but on the roof of a two-story building. > > You might do pretty well with some top-loading wires and perhaps you > could use a mast to give it a little more height. > > 73, > > Dave K8MN > > On 04-Jun-19 19:14, Mark - N5OT wrote: >> Hi Roy - you mean for 160 meters??? I think there are plenty of >> credible ways to cobble odd pieces of tower together to make a useful >> antenna, especially if climbing it is never something you need to do, >> and if it crashed to the ground it's not that big a deal. >> >> If you're asking if a 30 foot vertical can be made to be useful on 160 >> meters, I think, depending on the definition of "useful" the answer >> can definitely be YES and I can think of a whole lot of QSOs that have >> been made with verticals about that tall. >> >> 73 - Mark N5OT >> >> >> On 6/4/2019 8:41 AM, Roy Morgan wrote: >>> Hello Topbanders, >>> >>> I have three 10-fot sections of triangular steel tower, about 8 >>> inches on a side. >>> >>> Is it practical for me to make a useful vertical with these, either >>> bottom fed or gamma matched? >>> >>> Thanks for advice or experience. >>> >>> >>> Roy Morgan >>> K1LKY since 1958 >>> k1lk...@gmail.com >>> >>> >>> >>> >>> _ >>> Searchable Archives: http://www.contesting.com/_topband - Topband >>> Reflector >>> >> >> _ >> Searchable Archives: http://www.contesting.com/_topband - Topband >> Reflector > > > > --- > This email has been checked for viruses by AVG. > https://www.avg.com > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Topband: [Fwd: Re: 4U1ITU & K8GG operating 160.]
Hi Steve, Hi Topbanders, Good to see the post on Topband reflector. Yes, I was there in December 1987 when we visited my wife's cousin's family east of Geneva and I met Steve, AA4V at 4U1ITU. We only had a few days in Switzerland, and I drove in every morning for the sunrise openings on 160 & 80 meters. Conditions were not great, but I did work a few US stations including NR1R on Topband if my memory is correct. I was also there in December 1977 when the cousin's family lived in an apartment in Geneva within walking distance of 4U1ITU. Conditions were better at that time, as was the 160 meter antenna. As Steve mentioned, joining the 4U1ITU radio club made it easy to use the station. It is important to familiarize yourself with the station set up and learn the over-night access routine during the day time. To get the actual membership card one needs to join ahead of time and make an appointment with the station manager. It also helps to know a little French for the security guards. Most of the cousin's family now live in The Netherlands, so I will not be going back to operate. Also I am twice the age now and getting up early is much harder to do. HI 73 & GL to all, George, K8GG. > > I operated from ITU many times in the 1980âs. The sloping wire from the > building to the ground had just been installed by Paco EA(?) who along > with Ted Robinson ran the club station. I traveled throughout Europe for > my company usually planning air departure from Brussels to Geneva. Iâd > operate all weekend and departed on Sunday evening by train to my next > appointment on Monday in Zurich. I ran into George K8GG a few times. His > wifeâs family lived in Lausanne, about 40 km from Geneva. I spent a lot > of time on 160 at Geneva sunrise and worked many stateside on top band. > Many mentioned that it was an ATNO on 160. > Very nice setup in those years. Access to the club station was easy if you > joined the 4U1ITU club. Donât know about now. > 73 > Steve AA4V > > Sent from my I-Phone > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Top band portable antenna.
Iain, Etc., Some years ago I operated 160 and 80 from PJ4-Bonaire. W8UVZ, KD9SV and I used a single pennant antenna aimed at Europe with good results. Bottom about 6 feet above ground, 14 feet of vertical wire with the 910 ohm load resistor in the middle and two sloping wires, 30 feet long each to the feed point with an 18:1 transformer for 50 ohm coax to the RX port on the transceiver. These antennas can be "redirected" by moving the feed point which is the "back end", so one could start out looking NE for Europe and then NW for Asia and W or SW for Oceania before sunrise. It all depends what you have to tie off to on the back end. We found that trees, and masts, both metallic and non-metallic make good front supports as long as the vertical wire is about 3 feet or 1 meter away from the mast. I hope this helps. 73, GL, George, K8GG > Hi. > > > > Some remember my post about VK-V31 top band possibilities last year as I > was > travelling there on holiday. > > Many useful responses, you will be glad to know my 100W into an inverted-L > over seawater made 1 VK QSO, a few JA and a few Russia which is quite good > going from there.. > > My Rx antenna was a no go, too much local QRN and tropical storms, the Tx > antenna was 100M away so I ended up using that for rx. Not brilliant but > better than nothing. > > This year I return but this time have room for a proper vertical and Rx > antenna though this time far inland and thus no sea water. I was thinking > some sort of top loaded vertical and whaler loop? > > Considering I have to fly with the kit but am willing to pay a little > extra > in terms of weight if absolutely necessary, what would you suggest is a > good > top band TX/RX antenna combo for a single traveller? > > > > Iain G4SGX > > > > > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Impedance of inv l?
Hi All, Frank is correct. We originally designed the Battle Creek Special to use 16 radials 1/4 wavelength long on 160 (about 135 ft each) and then found that 32 radials 1/8 wavelength long (about 70 ft each) were much better for 160, 80 and 40 meter radiation. With 50 feet of mast and an 80 meter trap on top and the top loading wire, the feed point impedance on 160 is about 25 ohms, of which almost half is ground losses as determined by a DXpedition on a Pacific island that found a 13 ohm feed point on a beach over salt water. GL, 73, George, K8GG > > Hi Jamie, > > > I use my AA-54 frequently in exactly the manner you're using your > AA-23, I've never had any reason to be suspicious of any of its > readings. I'm lucky to have no AM broadcast stations within ten > miles. > > > Your AA-230 is telling you that at least half of your power is being > lost to ground resistance and need to at least double the number of > radials to significantly reduce your resistive losses. > > > The 2000 feet of wire in your radial system likely would have produced > much better results with twice as many radials of half the radial length > you used. Quarter wavelength radials aren't cost effective until many > more than 60 radials are used. > > > www.w0btu.com/Optimum_number_of_ground_radials_vs_radial_length.html > > > 73 > Frank > W3LPL > > > > > - Original Message - > > From: "Jamie WW3S" > To: "Topband" > Sent: Sunday, November 18, 2018 10:33:13 PM > Subject: Re: Topband: Impedance of inv l? > > several have asked how I am measuring the impedance.I'm using an > AA-230, > and am all the ALL PARAMS setting.the 230 defaults to a series model, > is > that what I want, donât see how to change it to parallel. I think the > symbol > for impedance is |Z|, correct? > > -Original Message- > From: F Z_Bruce > Sent: Sunday, November 18, 2018 3:20 PM > To: wes_n...@triconet.org ; Topband > Subject: Re: Topband: Impedance of inv l? > > > The far end is high impedance voltage, and has minimum horizontal > current radiation. The inverted L is a good trade off signal vs > available height. Not an expensive antenna to build. > > 73 > Bruce-k1fz > > On Sun, 18 Nov 2018 12:31:38 -0700, Wes Stewart wrote: > > That also drives up the current in the horizontal wire with attendant > increased > horizontal radiation. > > I chose for a couple of reason to do the opposite; shorten the wire to > make > the > feedpoint capacitive and use a shunt inductor to get a 50-ohm match. > This > really doesn't improve the 2:1 VSWR, that I consider acceptable, however. > > Wes N7WS > > On 11/18/2018 8:55 AM, F Z_Bruce wrote: > That sounds about right. As you put a good ground system under it, > that > value will come down, and the efficiency will come up. > > Many add extra antenna wire that pushes the current up the wire, this > also raises the impedance, hopefully to near 50 ohms with the right > length. > A capacitor (variable, then fixed) in series at the feed point can > cancel the added inductance. > > 73 > Bruce-k1fz > https://www.qsl.net/k1fz/beverage_antenna.html > > > On Sun, 18 Nov 2018 10:41:36 -0500, WW3S wrote: > > What should the Z be for a 1/4 wave inv l, with the radials attached > to > a radial plate? Mine seems to be 60 ohms or so > > Sent from my iPad > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > > --- > This email has been checked for viruses by AVG. > https://www.avg.com > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: 160m Condx
Filipe: In the USA and Canada: 1810, 1820, 1830, 1840, 1850, 1860, 1870, 1880, 1890, and every 10 KHz through 2000 KHz. I missed some Eastern Europeans because they TX on 1870 in CQWW CW Contest and we have loud 'birdie" signal from two nearby AM broadcast stations near my QTH. 73, George, K8GG.. > Hi > > Is there a listing of such frequencies? Want to avoid those in the coming > contests > > 73's Filipe > CT1ILT CR5E CR6K > > Sent from my Huawei Mate 8 > > Na(o) Seg, 12 de nov de 2018, 17:28, Mike Waters > escreveu: > >> I wish we could get the word out to avoid frequencies like that: 1810, >> 1820, 1830, etc. There are almost always AM BC harmonics on those freqs. >> >> 73, Mike >> www.w0btu.com >> >> On Sun, Nov 11, 2018 at 4:24 PM k1zm--- via Topband < >> topband@contesting.com> >> wrote: >> >> > >> > Band still down a bit from last week but 4k6fo good sigs now on 1830.0 >> > from Alim. >> > 73 JEFF >> > _ >> > Searchable Archives: http://www.contesting.com/_topband - Topband >> > Reflector >> > >> _ >> Searchable Archives: http://www.contesting.com/_topband - Topband >> Reflector >> > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Shunt feeding AB-577/621
Hi All, A couple of thoughts: I used an aluminum powder filled version of Permatex or similar anti-seize compound the last time I put up an aluminum tower (Heights or Universal). No continuity problems. Also with a rigid galvanized free-standing tower (Probably American Tower or Pyrod) I used zinc filled anti-seize compound on the face of the flanges between sections. No conductivity problems for the 16 years it was up with a shunt feed for 160 meters. The AB-577 is probably resonant near 3.5 MHz with the C-3 antenna on top if one wants to shunt feed it for 80 or 75 meters. So, I vote for an inverted-L for 160 either supported from the top of the mast or from a separate tree. GL & 73, George, K8GG > Hi Pete, > > Good question. I haven't done it with any of my three AB-577s, but I've > seen recommendations from others that the sections be electrically bonded. > > I'm not sure about the case for that. I just measured continuity on the > flat portion of a spare tube and it showed zero ohms. If the contact areas > are clean when the mast is assembled, they should make good contact with > zero resistance. The clamp should act to keep the flat areas in contact, > as should the downward pressure from the guys. I guess it may be possible > that dirt carried by rain water might seep into the clamp and get between > the sections as they rock back and forth in the wind, even if it's just by > nanometers. > > If you buy that possibility, I think it can be overcome pretty easily by > attaching right-angle tabs to the top and bottom of each section with > screws/nuts, and running a section of copper strap between them, also > secured with screws and nuts, or perhaps you can find some sort of clamp > that would let you quickly connect/disconnect the strap as you raise/lower > the mast. > > Hope this helps. > > 73, Dick WC1M > > -Original Message- > From: N4ZR > Sent: Monday, October 1, 2018 11:48 AM > To: topband reflector > Subject: Topband: Shunt feeding AB-577/621 > > I have an AB-577 with a C-3E on top, and am interested in the possibility > of shunt-feeding it for 160 - 100 watts only. Anyone have any experience > with doing this? Are the section-to-section joints adequately conductive? > I would plan to use an omega match, because I'm guessing it would be well > short of a quarter wave. > > My other option is an inverted L. Should I maybe just go ahead with that? > > -- > > 73, Pete N4ZR > Check out the Reverse Beacon Network > at <http://reversebeacon.net>, now > spotting RTTY activity worldwide. > For spots, please use your favorite > "retail" DX cluster. > > > > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Beverage Antenna Tuning
Hi Ash, Hello All, As a long time Beverage user, I can definitely say that the performance can be enhanced by having good ground at the termination resistor end of a beverage. Operating from Aruba in a CQ160CW contest, W8UVZ, KD9SV and I put out a proper 470 ohm non inductive resistor on the end of a 560 foot long beverage, and in addition to the ground rod, fanned out about 8 radials each about 17 feet (5 meters) long beyond the end of the beverage antenna wire. I will also state that putting a Hi-Pass filter in series with the coaxial cable at the receiving end in the radio room was a big help. I lived 1/2 mile from an AM 930 station that made it impossible to make measurements with an SWR bridge in a receiving mode. The only way I could evaluate my RX antennas was to transmit 2 - 3 watts into the beverage and use a low power SWR bridge to look at the forward & reflected power, which worked very well for me. My typical SWR on 160 meters was 1.5:1 from 1800 to 1915, and I considered that good enough. I did not worry about the SWR on 80 or 75 meters, but found good receiving advantages compared to my transmitting antenna most of the time. 73, Good luck, George, K8GG > At 14:33 2018-07-06, Ashraf Chaabane wrote: >>Hi Mark, Peter, >> >>The BC station to be used to minimize the back lobe would be in >>Egypt or Saoudi Arabia right on the back of my beverage antenna. >>That should offer signals coming well above 10deg (I presume!). >>Comment noted regarding how efficient that will be on 1820 kHz. I >>know Egypt has BC station on Medium Wave which isn't that far from 160m. >> >>Frank, >> >>I have two 3-feets rods at each end so far with two buried radials >>at the feed end. I will add radials at the termination side as well >>as you recommend. >> >>For the sake of experimentation, I will play a bit with the >>termination resistor trying to flatten the SWR curve as much as >>possible, although, as many said, I shouldn't expect a noticeable >>improvement in reception. >> >>Thank you all and those who wrote me in private. This generous >>technical support is needed for developing experience on 160 among >>3V hams (mostly youngsters). I hope we will be ready with strong >>100W signals this winter! >> >>73 from Tunisia >> >>Ash 3V8SS/KF5EYY >>www.kf5eyy.info >> >> >> >>-- Original Message -- >>From: donov...@starpower.net >>To: topband@contesting.com >>Cc: "Ashraf Chaabane" >>Sent: 04/07/2018 19:00:33 >>Subject: Re: Topband: Beverage Antenna Tuning >> >>>Hello Ash, >>> >>>Your results are normal for a typical Beverage. Receiving performance >>>is not significantly degraded by imperfect matching of the coaxial >>> feedline >>>to the Beverage feed point or by non-optimum termination resistance. >>>You could optimize your matching transformer and termination resistor >>>but the improvement in receiving performance will be very minor. >>> >>>On the other hand, Beverage antenna receiving performance can be >>>significantly degraded by: >>> - nearby antennas, power lines and other long conductors, and >>> - common mode signals coupled into the feedline >>> >>>You could optimize your matching transformer to reduce the VSWR to >>>closer to 1:1 on the frequencies you care about most, but you won't >>>notice any improvement in receiving performance. >>> >>>You could optimize your Beverage termination by: >>>- adding extra ground rods and/or short radials to improve >>> ground resistance >>> stability at the connection to termination resistor. >>>- adjusting the termination resistance to minimize the VSWR >>> excursion >>> as you sweep from 1.5 to about 10 MHz >>> >>>73 >>>Frank >>>W3LPL >>> >>> >>>From: "Ashraf Chaabane" >>>To: topband@contesting.com >>>Sent: Wednesday, July 4, 2018 2:13:27 PM >>>Subject: Topband: Beverage Antenna Tuning >>> >>>Hi All >>> >>>I measured the SWR in my beverage antenna; the SWR fluctuates between >>> 1.5 >>>and 3 in a range of 1.8 to 7 MHz. (See: >>>https://drive.google.com/drive/folders/0B9AtNpPfAOUMRDNsaXROMG1VUTg?usp=sharing >>>) >>>I know SWR should not vary too much. However, some people are suggesting >>>adjusting the termination resistor. Others suggest checking the >>> transformer >>>number of windings for a good match. What shall I do? >>> >>>73 Ash 3V8SS/KF5EYY >>>_ >>>Topband Reflector Archives - http://www.contesting.com/_topband >>_ >>Topband Reflector Archives - http://www.contesting.com/_topband > > Nick Hall-Patch > Victoria, BC > Canada > > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: cutting coax stubs for 80 meter 4-square
Hi All, I was discussing this thread with a microwave engineer on 75 meters this morning and he reminded me that I had AM RF in my RX antennas at my previous QTH. So much that I used Hi-Pass filters on my beverages and pennants. Terry, Do you have an AM radio station near by that could be messing with your instruments? Just a thought. GL, de George, K8GG > Hi guys and gals, > > > Well, to make a long story short my Rig Experts AA-170 has quite working. > Looks normal but a 56 ohm resistor at the end of the 75 ohm coax reads > infinite. On the MFJ-259b it reads 56 ohms. Check SWR and the MFJ reads > 7.499.2 Mhz 1.1:1 SWR R=56/57 ohms X=0. Coax is 55' 4 3/8" long when I got > very near 7500 KHz. With the shorted coax the MFJ-259b read 7.484.2 to > 7.523 Mhz, 20.2 SWR, R=2 ohms, X=0. Seems like the velocity factor is > considerably higher than what was stated to me by DX Eng.. The velocity > factor is some where around 0.84401... as best I can figure it. So I guess > that makes it 0.84 VF FWIW. > > > Anyway, I have it figured that 55' 4 3/8" will do the trick for my 80 > meter 4-Square at 3.750 Mhz. > > But why my RE analyzer went out today I don't have any idea. Back to the > MFJ! > > > Terry > > KI7M > > >> On June 9, 2018 at 6:59 PM terry burge wrote: >> >> >> Good point Wes. I will see if I can find a decent value of resistor. >> My Rig Experts AA-170 was purchased because I did not trust the >> readings my MFJ-259b was giving me while working on my hytower. >> Pretty penny for these antenna analyzers. But I will bet if it won't >> do the stub frequency checks it won't do the velocity factor and >> more. Did work pretty good for checking SWR and feedpoint impedance >> on antennas like the hytower. Really liked it until this. >> >> >> Terry >> >> KI7M >> >> > > On June 9, 2018 at 5:11 PM Wes Stewart wrote: >> > >> > >> > Since he said the coax was 75-ohm, a 75-ohm termination would >> be better. >> > >> > >> > On 6/9/2018 5:07 PM, Richard (Rick) Karlquist wrote: >> > > > As a sanity check, terminate the coax with a 50 ohm >> resistor and verify >> > >> > > > > that you have good coax. Flat line at 1:1 SWR, etc. >> > > >> > > Rick N6RK >> > > >> > > On 6/9/2018 4:57 PM, terry burge wrote: >> > > > > > I don't know what is wrong here but I keep getting >> in this situation where my >> > > >> > > > > > > typing starts running back over my writing. >> I will try again to reply. >> > > > >> > > > >> > > > Joel, >> > > > >> > > > I have tried all that the manual says without >> success. All I see is the >> > > > horizontal solid and dashed lines of R and X. No >> indication of a resonance >> > > > point anywhere from 1880 KHz up to 10,500 KHz. Go >> figure? At least my >> > > > mfj-259b is working old as it may be. Rig Experts >> is going to get a nasty >> > > > note I think. Disappointing, huh? >> > > > >> > > > >> > > > Terry >> > > > >> > > > KI7M >> > > > > > > > On June 9, 2018 at 2:54 PM Joel Harrison >> wrote: >> > > > >> > > > > > > > > Hi Terry, >> > > > > >> > > > > I replaced the 1/4 lines on my 80 meter 4 >> square this past fall and used >> > > > > my AA-170 to set the length with no problem. >> > > > > >> > > > > Just select "all" for the mode and set the >> freq you're aiming for and then >> > > > > trim the line until X equals zero with the >> far end open. Should work fine. >> > > > > I always calculate the length x VF then add >> a few feet to start. >> > > > > >> > > > > 73 Joel W5ZN > > Hi guys and gals, >> > > > > > >> > > > > > >> > > > > > > > > &
Re: Topband: 80/160?
Jim, et. al., One can also use a spring loaded wide spaced solenoid contactor to get more voltage gap if switching to the 80 meter position. One of the problems is building a 1500 watt tuned tank coil for 80 meters to go from 50 ohms up to 2 KV or more at the feed point that is switched in for 80 and out for 160. In my opinion, it is just easier to not switch anything and put a trap in line. 73 & GL, George, K8GG > Rather than use a trap at the top of an 80m vertical to transition to a > 160 > inverted L has anyone tried a vacuum relay or even two in series at 1500w > to handle the highvoltage when on 80m? > > Tnx > > Jim AB3CV > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: FW: Excessive noise on beverages
Good point Frank, We had similar problems at a Caribbean Island ham station and used a pennant aimed at Europe with the back end pointed at the TX antenna about 100 meters away. Worked well that way. Their Beverage did not! George, K8GG > Hi Joel, > > > In my opinion your elevated radials are a show stopper for an adjacent > receiving antennas unless you can disconnect all of them when you're > receiving. > > > 73 > Frank > W3LPL > > - Original Message - > > From: "Joel" <k...@comcast.net> > To: "Herbert Schoenbohm" <herbert.schoenb...@gmail.com> > Cc: "TopBand List" <topband@contesting.com>, "kd9sv" <kd...@comcast.net> > Sent: Wednesday, March 7, 2018 12:48:57 AM > Subject: Re: Topband: FW: Excessive noise on beverages > > Hi Gary > Would you send the info you have re. tower detuning that you designed for > K3UR. (Am using 1/4 wl tower with elevated radials) > Thank you > Joel > k4wm > > Sent from my iPhone > >> On Mar 6, 2018, at 13:42, Herbert Schoenbohm >> <herbert.schoenb...@gmail.com> wrote: >> >> Great work Gary! This is probably a way that is much less expensive than >> the commercial version of doing this. >> >> https://www.lbagroup.com/products/detunipole-detuning-skirt-kit >> >> Herb, KV4FZ >> >>> On Tue, Mar 6, 2018 at 2:28 PM, kd9sv <kd...@comcast.net> wrote: >>> >>> Herb, FYI...gary, kd9sv >>> >>> -Original Message- >>> From: kd9sv [mailto:kd...@comcast.net] >>> Sent: Tuesday, March 06, 2018 12:59 PM >>> To: 'David Olean' >>> Subject: RE: Topband: Excessive noise on beverages >>> >>> Dave, I have recently developed a simple "tower de-tuning system" that >>> is >>> in >>> the "Beta Testing" phase. It will soon be available thru DXE as a >>> system >>> to >>> de-tune a tower but I have no plans to use it on towers being used for >>> transmitting, however; I did design a system for doing that which only >>> requires adding one RJ1A or Kilovac HC1 type vacuum relay. I built one >>> of >>> those for K3UL which he has not yet installed. I will send you the >>> drawing >>> if I can find it on my computer. How are you feeding your tower? Gamma >>> or >>> what? >>> >>> 73, de gary, kd9sv >>> >>> -Original Message- >>> From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of >>> David >>> Olean >>> Sent: Tuesday, March 06, 2018 12:30 PM >>> To: Topband Reflector >>> Subject: Topband: Excessive noise on beverages >>> >>> I have been putzing around trying to improve my 160 meter setup, and >>> have run into a real problem. Most of the USA is covered by two >>> directions from here in Maine. SW and W. My problem is that I have an >>> excessively high noise level on both of the beverages that run in these >>> directions. In the last six months it has gotten worse, and so bad that >>> I cannot use either beverage. The wires terminate at the side of my >>> barn where I have ground rods and the RG-6 goes through PVC conduit up >>> to the shack on the second floor of the barn. During the day I see >>> noise levels at -133 or -132 on the two wires, but at night the noise >>> had climbed to levels around -100 or to -110 on a good night. I >>> suspected that I was getting noise coupled in from my vertical which is >>> rather close and on the other side of my barn all of 55 ft away. >>> >>> Yesterday, I modified the west beverage and shortened it so that it >>> terminated about 150 feet away from the barn and I ran new coax back >>> across the field. I kept the SW beverage as is to compare noise levels >>> at night. Lo and behold, but the noise went to -110 on the SW beverage, >>> but only about -120 dBm on the modified beverage. This is a 10 dB >>> improvement. Other directions at night run at about -130, so I am now >>> seeing a 10 dB extra hit in noise to the west. >>> >>> The vertical is a shunt fed Rohn 25 with a total height just over 90 ft >>> with top loading from a 5 element long boom 10 Meter yagi. I am not >>> sure >>> if it is possible to simply un resonate this tower. Does anyone have >>> experience with simple ways to decouple a shunt fed tower from the rx >>> antennas? >>> >>> The extra 10 dB of noise that I get to the west and SW is mostly d
Topband: Conditions 0100Z to 0200Z 8 Feb 18
Hi All, Since Roger, G3YRO, suggested that Wednesday night was a good time for activity, and I happened to be at a radio, I turned on 160 and found some good strong signals: G3YRO 0102Z, OK1CW 0132Z, HG2DX 0136Z, and HA6FQ 0144Z. Nothing further east was QSOed although I could hear a whisper of a station much further away. 73 and Good Morning from snowy Michigan, George, K8GG _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Working Dupes on a Band
Fellow Topbanders: Sometimes I hear a DX station calling CQ and no one else calling. I think it is good practice to let them know they are getting out, no matter how many times I have logged them before. I believe this is common courtesy to let the DX station know he/she is being heard. 73, George, K8GG _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: No 160m Sunrise Peak
Roger, Et. Al., On the contrary, Sunday morning in the CQWW 160 CW there was a peak observed from Michigan. A very weak EI4??? called me about 0730Z without a QSO. Then G3PQA popped up solid and we made a QSO easily. That was followed by an EI2 who was good copy, F6ARC, and a DJ4 in total sunrise about 0745Z. They were 579 to 589 despite contest intermod at W8RT, the Low-Band contest station near Battle Creek, Michigan. Also an LA station was hunting and pouncing at that time and, although he did not call me, he was louder than when calling CQ and running on a fixed frequency. 73, George, K8GG, 2nd operator in a Multi-Operator Hi-Power entry. > > Just to re-state something I posted a few weeks ago . . . > > I made a point of checking signal strengths last weekend in the CQ WW. > > Once again, there was absolutely NO increase in signals strengths around > our > Sunrise (0730Z), and if anything they started to drop off. > > This was regardless of how far west the stations were. > > Don't ask me why . . . in the old days, you would only bother coming on > around Sunrise to work DX, as signals would increase by as much as 10 - > 20dB. > > Roger G3YRO > > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Choke?
Jeff, Et. Al., Rather than wrap the wire around the insulator opening or itself, how about a "split bolt" wire clamp with the saddle on the tension side? A good "mechanical knot". I can take photo of one if needed. Here is a website link: http://www.elecdirect.com/split-bolts-grounding-products/split-bolt-connectors/copper-alloy-2-conductors-16-str-8-str There is a larger one on the same "elecdirect dot com" page on the internet as well. GL & 73, George, K8GG > I'll be erecting a 95-foot Inverted-L antenna. At the shack end of the > antenna, right before the insulator, I'll need to wrap the wire around > itself a few times so that it doesn't slip through the insulator. Because > the wire itself is insulated, is there any negative affect, such as a > choking action that might take place? > > 73, Jeff KH6O > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Bury beverage wire?
Martin, et. al., For temporary work from Curacao, we taped beverage wire to the asphalt pavement for an E-W beverage that worked OK (we did not model it), and allowed us to QSO Central American stations, like XE and TI that were not heard on the NNW beverage for NA and Asia or the TX antenna. If your pavement is concrete, can you locate the wire in a joint? I am not sure about truly underground. Maybe you can model it? I have a friend who has coax underground and starts his beverage on the far side of the road with a transformer and ground system. That way there is no buried portion of the RX antenna. 73 and GL, George, K8GG. > Topbanders, > if crossing a driveway above ground is not an option, is ist ok to bury > the beverage wire for, say, 20 feet? > > -- > > Ohne CW ist es nur CB.. > > 73, Martin DM4iM > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Long sloper
Hi Gary & fellow Topbanders... It seems that Gary's 129 foot wire may be actually 133 to 136 feet long, depending on radials and ground conditions and whether the wire is bare or insulated. I did a quick model on a recent version of EZNEC and found that Gary may have to add series capacitive reactance of somewhere between -25j to -40j ohms to get to about 1835 KHz resonance with minimum SWR. XC = -40j requires about 2200 pfd series capacity. XC = - 25j is about 3500 pfd series capacity. The formula is XC = 1/(2 x Pi x F x C) Where F is in Hertz or Cycles and C is in Farads The voltage requirements are not too high but there will be at least 5 or more amps of RF if you run power, depending on the impedance at your feed point. For safety sake I would use 2500 volt ratings on fixed caps and 3KV on vacuum variable caps.If you have a favorite center frequency, combinations of 200 to 500 pfd mica or door knob caps should be sufficient. If you use door knob style ceramic caps, use a lot of them in parallel, as they do not like high current. When done building a bunch of parallel capacitors for the value you require, try a KW for a few minutes at the desired frequency for minimum SWR and make sure there is no drifting of the value of XC (detuning of the series reactance). Then turn off the transmitter and go out and carefully feel the capacitors to make sure they are not very warm. I ran 3 - 4 amps through four 1000 pfd, 5 KV caps in series once and darn near blew them up. 73 & Good Luck George, K8GG > I just installed a replacement wire for > the 160 sloper. I made it 129' as was the > earlier one that came down in the winds. I > have to use a spud gun to get fishing line > over the tree tops and where the spud > lands, I connect the wire to the eye > fastener & reel it to the radial plate. > This time I had to use a different tree as > the earlier one came down in the last > hurricane. > > Now it is resonant at 1.785 and it is not > a problem at the lower end of 160 but > higher up it is. My problem is compounded > in that I also use this antenna for 10M, > 12M and the upper part of 15M. I need to > shorten it for use on these as well. > > It is too far away to shorten the wire and > solder a new eye on it and now it is too > cold to play with it on the tree (have > difficulty walking right now). So being > too long, capacitance at the feed point > might be my best answer. I have several > fixed vacuum & doorknob capacitors of > small pF to choose from that I can put in > line. Is there a formula that I might plug > data into to come up with the needed pF? > > Thanks & 73, > > Gary > KA1J > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: FT8 discussion
Ladies and Gentlemen, Isn't it time to just stop the discussion?? 73, George, K8GG _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Rotator creating spur on 1820
Jerry, et. al., I didn't have the problems from my own installation, but I used to live about 1/2 mile from an AM 930 station and there would be a 2nd harmonic spur at 1860 and a mixer spur of 2 x 1400 - 930 = 1870 KHz. W0CD helped me find & build hi-pass filters in old ARRL Handbooks for my RX antennas. The only way I could check the SWR was to turn the transceiver down to about 2 watts and feed the beverages or pennants and scan the band to make sure the terminations, etc., were OK. I have repeatedly missed a couple of 160 contest stations in the former Yugoslavic area because they would run on 1870. Even 4+ miles away at W8TOP in the CQ160 CW Contest there was no way for us to listen thru the harmonic mixer. There was always some diode rectifications off site so to speak. We suspect old support towers for FM stations and a nearly abandoned AM station between the AM930 and W8TOP, but, since the spur is not on site, we just live with it. The suggestion of a jumper across the rotator makes good sense if some dissimilar metals in the unit are making the diode. GL, George, K8GG > Likely all the spurs you see on 160 that are caused by AM stations will > land on 10 kHz increments because the stations are spaced on 10 kHz > increments. I identified one of the stations that was a big contributor > to my problem and that was on 1730. I haven't found the other station > yet. I expected the station on 890 to be a contributor since it is only > 1700 ft from my antenna but I don't think it is the one. (It is a > contributor to the spur that happens on 3510). Regardless of which > stations are involved, the main problem is that the mixing is being > created near my rotator, and probably inside it somewhere. I have to > kill the mixer somehow. More than likely the stations are clean. It > will be interesting to see if the same mixer is causing both spurs, 1820 > and 3510. Fortunately the 3510 spur goes away at night because one of > the contributor stations is daytime only. > > Interesting video by N8PR, but he is fighting a different problem from > what I have, > > I do not have a strap around the rotator. That's worth a try. Thanks > Lloyd and Hank. > > Jerry, K4SAV > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: A way forward to keep 'old school' modes vibrant alongside FT-8? (long)
Gentlemen: Tim writes very well below. However, I have had 45 or more FT8 emails and I truly think we are airing the same laundry many times. Steve Ireland did raise a very good point..but While I respect all the varied opinions, it may be time to stop beating the modes to death (new and old) and get on with real stuff like how strong or weak the H40 station was two days ago, how strong 3C0L was the other night, or the VK9 announcement about 4 square RX antennas with no preamps at the verticals. Thank you for your patience... mine has gone click-click-click on the delete button many times this week. 73 to all, George, K8GG > Quoting ARRL Contest Update for October 18 2017: > > "FT8 mode usage continues to increase! According to a tweet by Michael, > G7VJR, operator of Club Log, "In September 2017, the number of FT8 QSOs > uploaded to Club Log was the same as CW and SSB combined." (Bengt, K7ADD)" > > DXCC concept of "by mode" awards has been reworked several times in the > past 70 years and I don't see why it can't be reworked again. > > In 1940 only 4 hams had "radiotelephone" DXCC. > > It wasn't until the mid-1970's that they made a certificate for CW. > > I'm not sure when RTTY DXCC Certificate began but it morphed into > "Digital" > in 2011. > > I do a lot of RTTY contesting and think I've built up a good skillset for > that particular mode. > > I've made a few dozen FT8 QSO's, kinda have the basic hang of it, but I'm > sure the FT8 experts know more than me about how to work rare DX with it. > When we get a truly rare dxpedition using FT8 they will have to manage the > pileup somehow, I'm actually looking forward to see what operating > practices are adopted. > > Tim N3QE > > On Thu, Oct 26, 2017 at 11:10 AM, Nick Maslon - K1NZ <k...@arrl.net> > wrote: > >> Hi Dale, >> >> My comments were more aimed at the "let's separate FT/JT modes into >> their >> own separate DXCC category and disqualify them from Mixed" sentiment. I >> have no problem with the per mode style DXCC awards. I just wanted to >> point >> out that someone can't retroactively change the definition of Mixed >> because >> they don't like a specific mode being in there. I guess I wasn't as >> clear >> as I could have been in my phrasing. >> >> 73, >> Nick K1NZ >> >> On Thu, Oct 26, 2017 at 11:04 AM, Dale Putnam <daleput...@hotmail.com> >> wrote: >> >> > Hi Nick, >> > >> > Not necessarily needed retraction. Not at all.. >> > >> > It seems to me that a solely one more or other.. is called for, also, >> > >> > a mixed mode, already in place, with any or all of a mix of modes. >> > >> > These are all digi modes that I am speaking of. >> > >> > Pretty much the same as "phone" awards.. doesn't care if it is FM >> voice, >> > SSB voice, or AM voice. >> > >> > Neither would the "digi" award.. but the difference would be noted >> with a >> > single mode cert. >> > >> > >> > Have a great day, >> > --... ...-- Dale - WC7S in Wy >> > >> > "Actions speak louder than words" >> > 1856 - Abraham Lincoln >> > >> > >> > -- >> > *From:* Topband <topband-boun...@contesting.com> on behalf of Nick >> Maslon >> > - K1NZ <k...@arrl.net> >> > *Sent:* Thursday, October 26, 2017 8:58 AM >> > *To:* topband@contesting.com >> > *Subject:* Re: Topband: A way forward to keep 'old school' modes >> vibrant >> > alongside FT-8? (long) >> > >> > I just have one question about your suggestion about creating a "new" >> digi >> > DXCC award and excluding JT/FT modes from mixed. Are those people >> (myself >> > included) who have applied JT/FT credit to their Mixed award and >> received >> > it as such going to have to mail the certificate back to the League >> and >> > have the award retracted? It will be difficult to retroactively create >> a >> > "new" award without including every mode in mixed, which by definition >> is >> > mixed. Creating a "Mixed but without JT/FT modes" DXCC is getting into >> the >> > splitting hairs and logistics nightmare ballpark. >> > >> > PS. I am also one of the <30 crowd. >> > >> > 73, >> > Nick K1NZ >> > _ >> > Topband Reflector Archives - http://www.contesting.com/_topband >> > TopBand Mail List Archives - contesting.com >> > <http://www.contesting.com/_topband> >> > www.contesting.com >> > Topband Mailing List Archives. Search String: [How to search] Display: >> ... >> > >> > >> > >> _ >> Topband Reflector Archives - http://www.contesting.com/_topband >> > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Topband Digest, Vol 177, Issue 1
Gary et. al. We used that configuration over radials on ground on Curacao in the mid-1990's from the end of the resort near what is now PJ2T. It is really closer to 5/16 wl, and with half vertical and half horizontal it came very close to Z = 50 + maybe 200j ohms. We used a series vacuum capacitor about 450 pfd to tune out the inductive reactance and it worked very well. We had about 40 or 50 radials approx. 80 feet long spread out on the sand and coral along the shoreline. After the CQ160 CW contest we inserted an 80 meter trap about 75 feet up and it worked very well on both 80 CW and 160 CW for the next few days before we had to pack up and go home. (The support we used one of the crank up towers the Finn's had left from their massive CQWW DX Phone and CW efforts a few year before.) I cannot comment on the FCP's. GL, George K8GG > 160 i l with FCP > Everyone has been so helpful > I'm going to throw this out here for everyone > A 3/8 inverted l cut for 160 fed at bottom about 170 feet ,equal lengths > for vert and horizontal using an FCP's > thoughts on 3 independent FCP's > > one for 160 one for 80 one for 40 > Can the FCP's be in parraled > Or should they be switched > The horizontal arm end from this qth points ne ,perfect for Europe ,or > should I broadside the horizontal section ne by sw ? > Or am I wasting my time with 3 FCP's > 73 > Gary > N6biz > > > > > Sent from my iPad > >> On Sep 1, 2017, at 9:00 AM, topband-requ...@contesting.com wrote: >> >> Send Topband mailing list submissions to >>topband@contesting.com >> >> To subscribe or unsubscribe via the World Wide Web, visit >>http://lists.contesting.com/mailman/listinfo/topband >> or, via email, send a message with subject or body 'help' to >>topband-requ...@contesting.com >> >> You can reach the person managing the list at >>topband-ow...@contesting.com >> >> When replying, please edit your Subject line so it is more specific >> than "Re: Contents of Topband digest..." >> >> >> Today's Topics: >> >> 1. Re: Inverted L successes (garyk9gs) >> 2. Re: Inverted L successes (Glenn Wyant) >> 3. Re: Inverted L successes (GaryK9GS) >> 4. Re: Inverted L successes (Mike Waters) >> 5. Best Receive Antenna over Sloping Terrain? (Ed) >> 6. Re: Best Receive Antenna over Sloping Terrain? >> (Herbert Schoenbohm) >> 7. ZL3IX (Joe Galicic) >> >> >> -- >> >> Message: 1 >> Date: Thu, 31 Aug 2017 16:15:24 -0500 >> From: garyk9gs <garyk...@wi.rr.com> >> To: topband@contesting.com >> Subject: Re: Topband: Inverted L successes >> Message-ID: <6C.55.25924.D6C78A95@dnvrco-omsmta02> >> Content-Type: text/plain; charset=utf-8 >> >> But being 800+ miles closer to EU (many countries there compared to >> North America) and a path that is largely over salt water is a huge >> advantage, particularly on the low bands. >> >> >> 73-Gary K9GS? >> Original message From: Carl <k...@jeremy.qozzy.com> >> Date: 8/31/17 3:08 PM (GMT-06:00) To: GaryK9GS <garyk...@wi.rr.com>, >> topband@contesting.com Subject: Re: Topband: Inverted L successes >> Most of LI is glacial sand and only the coastal areas benefit verticals. >> >> Carl >> >> >> - Original Message - >> From: "GaryK9GS" <garyk...@wi.rr.com> >> To: <topband@contesting.com> >> Sent: Monday, August 28, 2017 8:22 PM >> Subject: Re: Topband: Inverted L successes >> >> >>> >>> I suspect that your success is largely due to your location on Long >>> Island. >>> >>> 73, >>> Gary K9GS >>> Original message From: jayb1...@optonline.net Date: >>> 8/28/17? 5:22 PM? (GMT-06:00) To: Doug Ellmore <d...@ellmore.net>, >>> topband@contesting.com Subject: Re: Topband: Inverted L successes >>> Last fall I installed an ?S-9? 43 ft vertical, added a tapped loading >>> coil >>> at the base, with 10 on-the-ground radials about 100 ft long randomly >>> run >>> all over my 60x90 house plot. Rig is 300 watts - Started on 160 DXCC >>> with >>> 32 entities, finished DXCC in one winter season. >>> My secret: JT65 (tnx K1JT) >>> Try anything ? you will be amazed how successful you can be on top-band >>> with a little patience and VERY modest antennas. 73, Jay NY2NY >>> _ >>> Topband Reflector Archives - http://www.con
Re: Topband: Unterminated WOG/BOG
Hi All, IMHO, 150 feet of beverage for 160 is too little. I would prefer a pennant or flag loop antenna aimed at Europe. It works! Also, being only about 30 feet in length, one can keep it on one's property. At a previous QTH I spaced two pennants 160 feet apart, broadside, toward Europe and either fed them to a magic tee in phase. Worked well, did not pick up neighbor's spurious signals from home entertainment devices, etc. Even a single pennant works well enough, as long as one has a decent preamp. George, K8GG > I've discovered that the woods off the corner of my property give me a > good > straight run where I could run a 150' or so beverage pointed directly at > EU. > > The difficulty is...it's not my property there, but a wooded area > connected > to a neighboring apple farm. It isn't being used, but it's still a little > shady to run an antenna there. > > I was thinking of getting something like this > https://www.dxengineering.com/parts/svp-sv-bog and running a wire into > the > woods. > > The difficulty is that these seem to want to be terminated at the far end, > but I've seen people talking about using them unterminated. Given this > isn't my land, I'd rather not drive a ground rod on the far end - we also > have pretty rock soil and getting the rods into the ground is a bear. > > -Can I only have a ground rod at the near (feed) end and just leave the > far > end unterminated? > -If I ran a longer wire, but zig zagged it how would that affect the > receive ability? > > I figure a black length of wire laying on the ground will go basically > un-noticed and be out of the way. Any thoughts? > > Sean Waite, WA1TE > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Radials question
Hi Mike, et al, Here are my thoughts interlaced. > Hey Topbanders, > > I was looking to buy or make a mono type 80 meter antenna for DXing. > > I was wondering couple things. If I make a full quarter wave vertical WIRE > in tree 65 feet tall and see DX Engineering verticals claim 65 foot tall > but wider bandwidth. What is their secret or just advertisement? ***Using a wire - say 12 gauge - Will probably give you a 100 kHz 2:1 SWR bandwidth. Using a vertical say 2" O.D. at the bottom and 1.25" O.D. at the top will generally triple the bandwidth. Make a model with EZNEC (r) and see what you get. Ground losses also increase band width of these antennas, since "Rg" is in series with the actual antenna impedance. > > Second question, I understand more radials make vertical better, but > what > happens if one side half or one third the length radials due to space in > yard are shorter by 20 to 30 foot? Is it noticeable enough to buy a > vertical in middle of yard instead of wire in tree towards side of yard? > Dollars verses radial lengths. ***It does not make a lot of difference. One K1 has a 160 vertical near his house and most of the radials are over 180 degrees. What is important is to get enough radials on/in the ground. > > Third and last question, can some of the radials, quarter of them, > overlap with radials of another antenna (160M mono vertical Gladiator > antenna)? Would it affect the performance noticeable. ###In my opinion, if the ground radials are below "elevated radials" for another antenna there should be no problem. The reverse is also true. I know a ham with 80 meter 4-square around a 160 meter vertical. The 80 meter radials are elevated and the 160 meter radials are in the sod. > > I don't need long answers, just something to help out a bit. > Not sure what antenna to buy or make yet. I am in 2 and half acres and can > maybe stretch in field next to me some with no one knowing. Not many 80M > momo antennas to choose from. > It is a late Summer or Fall project so time to think. > > Mike > n0 odk > 73 > thanks for suggestions gang. > _ > Topband Reflector Archives - http://www.contesting.com/_topband ***Good luck de George, K8GG _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Club Log issues Yemen 7O6T
Fellow Topbanders When I went to www.yemen2012.com and went to confirm my QSOs, the Club Log REQUEST QSL icon comes up with a line for each QSO checked in green. After filling in the dates and times and clicking on the Confirm QSO Details instead of getting feedback like the last DXpedition using Club Log all my entries go blank. Any suggestions? Please respond off line to k...@voyager.net or to k...@arrl.net Thanks 73 George K8GG ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: 706T on 160 and 80
Dennis, Fellow DXers. The log update I see is from 23:44 zulu on 11 May 2012 and last night's activity for US QSOs would have been after our sundown thru their sunrise which would be 0001 - 0200 zulu on 12 May 2012 - I think you have to wait for the next log update to see if you made it after sundown last night. Sorry if I misinterpereted, but that is what I think you asked GL 73 George K8GG Log shows most recent 160Q's from last night but the 80 meter Q's are all missing. Anybody know if there is a log problem or maybe it was Slim at the key on 80? 73, Dennis W0JX/8 ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: question about antenna bandwidth
Rob: A typical 3/8 wl inverted-L antenna is about 65 feet vertical and 125 feet horizontal or sloping back downwards at a slight angle. This means that 2/3 of the wire is horizontal near the ground and is a high angle radiator - semi NVIS - and the vertical part is radiating at a low angle. Not good unless you want to work a lot of US and nearby VE stations. It would be best if you can model the various configurations of 1/4 wl, 5/16 wl and 3/8 wl inverted-L antennas on a PC so you can see the results on the monitor and print them out for evaluation. IMHO going beyond 160 feet of wire inverted-L (5/16 wl on 160 meters) is not the best solution. Just my 2 cents worth 73 GL George K8GG Thanks, gentlemen (Eddy, K8GG, ZR, Roy, Herb, et. al.), for all the feedback on this. So, it seems it's pretty much what I expected -- if you tune an antenna for better results on one frequency, you detract from its operation on another. Maybe one of these days I'll get around to playing around with that 3/8 wavelength L anyway... Rob / KD8WK On Mon, May 07, 2012 at 03:22:19PM -0400, Herb Schoenbohm wrote: Another rule for this is the lower the Q of the matching network the greater the bandwidth. Herb Schoenbohm, KV4FZ On 5/7/2012 1:48 PM, Roy wrote: If I were to extend my 1/4-wave inverted-L to a 3/8-wave L, and tune out the inductance with a fixed capacitor at the base, what would this do to the broadbandedness of the antenna? There is an old basic principle to remember about this, The fewer the components in general, the broader the bandwidth. 73, Roy K6XK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Topband: Hi-Pass filter for 160 to reject BC Band
Fellow Topbanders: Another Hi-Pass filter is shown in the 1986 ARRL Handbook on page 30-24. It is also shown in other ARRL Handbooks. The original article was published in QST in Feb 1978 and was written by W3NQN, Ed Weatherhold. Charlie, W0CD, found he could spread a coil or remove a turn to customize the rejection for local stations. Although we do not have an actual filter-response curve, we were able to move F4 up to 1400 KHz to nul a local broadcast station just over a mile from my QTH, which seemed to also move the start of the attenuation closer to 1.8 MHz. This arrangement worked well for me with an AM 930 station running 1 KW at night only 1/2 mile from my QTH whether I was using a beverage or pennant receiving antenna that was receiving signals that had to pass by the AM 930 station to get to my QTH. YMMV GL 73 HNY George K8GG ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Fence ground screen instead of wire radials?
Brian - K1LI wrote: I remember seeing an article on this subject recently, I think in QST or QEX, but I can't seem to track it down. The author used various numbers and lengths of wire fencing instead of a conventional wire radial field. Can someone out there with better searching skills point me to the reference? Thanks, Brian K1LI I believe there is a reference in some of ON4UN's Low Band DXing books to using wire fencing for radials. I believe John rolls out wire fencing sections after the lawn mowing season is finished to enhance his ground system. GL 73 George K8GG ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Asymmetric radials for GP antennas; Just in case others seek what I've just found...
Cormac other Topbanders, In the new June 2011 issue of QST, page 42 there is an article about a vertical with only two radials on one side of a vertical radiator, and the directivity one gets by having losses in other directions with a very limited radial field or ground plane. If you can model your situation, you can get a pattern that will tell you about your compromise of having good radials only over 180 degrees. One of the W1-land DXers said he did very well with a good set of radials over 180 degrees and very little on the other 180 degrees due to site constraints. One of the W8's has a vertical near his house and has put radials across the ceiling of his cellar to fill in the ground plane. I did that at my first QTH as well, with elevated radials across the ceiling joists of a one-story house that seemed to work OK for me with random length elevated radials anywhere from 50 to 100 feet long behind the house to the trees and fencing at the perimeter of the lot. I have heard of others running radials through crawl space where there a house was built with no cellar and raised maybe 3 feet above ground level. Good luck, 73, George K8GG All, I've been searching for clarity and hard data on the effects of asymmetric radials on radiation patterns and efficiency of a vertical as I'm installing a 21m vertical for 80/160 and will have to live with a radial system that is significantly compromised over a 180 degree sector. I was a bit surprised to not find this subject dealt with in any clear decisive way in e.g. the ARRL Antenna Book or ON4UN's otherwise excellent Low Band DXing book (Did I miss it in either publication? If so, just send me a your an idiot email and I'll crawl back under my cabbage leaf suitably chastened). I was surprised as I had always assumed it is something many hams have to deal with unless they are prepared to go on stealth missions in the dead of night to lay radials on or under neighbours property (I don't recommend this course of action by the way; I attempted just such a thing once and got caught. As a mental exercise to occupy you during those quite times when calling CQ on a dead 160m, try explaining your way out of that one). On the basis that there might be one/some/many out there, who, like myself, are installing verticals with radial systems that are compromised directionally as well as length-ways, I just thought I'd share what I found; N6LF's excellent (if not exactly encouraging) summary of the consequences of asymmetrical radials at http://rudys.typepad.com/files/qex-ground-systems-part-7.pdf . It's well worth the read. I hope to hear you all on the far side of the Summer... -- Regards Cormac (EI4HQ) [Cork/UTC+1] http://86.43.106.118/ei4hq/ http://www.corkharbourweather.ie ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Topband: Topband Dinner Dayton 2011
Fellow Topbanders: Just a reminder that reservations for the Dayton Topband Dinner this year are available for a few more days. Reservations have to be made and paid by May 10th. No exceptions. We are at a new venue - the Crowne Plaza - with better seating and A-V than in prior years. Please visit www.topbanddinner.com for more details. 73, CU there George K8GG PS: do not reply to this e-mail - send reservation requests to k...@arrl.net Thanks ! ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Inverted L Proximity to RX Antennas
George (K8QM) wrote: All, I know it is important to keep RX antennas like flags, pennants and K9AYs as far away from TX antennas as possible. In the case of a quarter wave inverted L with approximately 50 feet vertical is it as important to keep the RX antennas away from the horizontal section as the vertical section? Thanks for any guidance. George K8GG comments: Yes, for sure for sure. Having a receiving loop under the top loading wire is not a good idea... Having a Beverage wire under the top loading wire is also a bad idea.. Both styles of RX antenna will couple to the inverted-L and the results will not be good! YMMV mine has not! GL 73 George K8GG ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
