Re: Topband: Temporary antenna suggestion for 160
Mike, I think the performance of a 4-square array may relate to the reason why switching to 30,000 feet of radials made a dramatic improvement. The currents in the elevated radial currents might be badly mismatched by proximity to currents in nearby radials. I never tried to measure them. 73 Frank W3LPL - Original Message - From: "Mike Waters" To: "Frank Donovan" Cc: "topband" Sent: Saturday, December 21, 2019 5:10:31 PM Subject: Re: Topband: Temporary antenna suggestion for 160 Hi Frank! Thank you for sharing this experience. This is interesting, because (as you are probably aware of) no less a guru than N6LF published results showing that with a single antenna, four λ/4 elevated radials were nearly identical in performance to 120 on the ground. This is true only if RF was prevented from either flowing into the lossy earth or back along the feedline shield (thus detuning the elevated radials, since the shield would try and act as a radial and couple to the lossy earth). Was anything connected to ground at the feedpoints? And what type of coax feedline choke unun did you use at the feedpoints? Perhaps there are factors in an array vs. a single vertical that would explain your results, but I can't think of any. 73, Mike W0BTU On Mon, Dec 16, 2019, 3:04 PM < donov...@starpower.net > wrote: Hi Mike, Years ago my 4-square transmitting array used "gull-wing" elevated radials sloping 45 degrees from the feedpoint at ground level to about ten feet high. When I replaced the radials with sixty 120-foot radials laid on the ground I had to shorten the verticals by about five feet to maintain resonance, suggesting that the current at the bottom five feet -- or so -- of the verticals was attenuated by the sloping radials in close proximity to the verticals. As an aside, the performance of the array improved dramatically... 73 Frank W3LPL From: "Mike Waters" < mikew...@gmail.com > To: "thoyer" < thoy...@verizon.net > Cc: "topband" < topband@contesting.com > Sent: Monday, December 16, 2019 8:52:41 PM Subject: Re: Topband: Temporary antenna suggestion for 160 CORRECTION It was just pointed out to me that I neglected to mention that the feedpoint on my 160m inverted-L was much lower than 10 feet high! The tuner sits on the earth, and the two wires go straight up from that to the insulator block holding the antenna and the radials, which is less than 4 feet high. From that point, the two radials angle upwards at roughly 45° (?) to nearby trees, and level out at 10' high to the North and to the South all the way to the ends. (The South radial zigzags back and forth since the distance from the base to the neighbor's fence in that direction is less than 1/4 wavelength.) I had photos of it online, but w0btu.com crashed. Looking for a place to upload it to. I hope this makes sense. Sorry for the lack of details below. 73, Mike W0BTU On Sun, Dec 15, 2019, 8:22 PM Mike Waters < mikew...@gmail.com > wrote: > Do the inverted-L, but use at least two 10' high 1/4 wave radials. > > Do NOT use an RF ground rod, or any radials on or near the earth. Just > connect the coax shield to the junction of the radials and any remote > tuner. At that point a good choke balun is necessary. > > Leaving out the choke or grounding the shield will result in very poor > performance. > > 73, Mike > W0BTU > > > On Sun, Dec 15, 2019, 7:04 PM thoyer via Topband < topband@contesting.com > > wrote: > >> With only 9 more to go for DXCC on 160 and all of the recent posts about >> how good the band has been recently "best in years) I find myself with >> no >> antenna for the low bands and cringing after each post on how good the >> band has been. >> ... >> Options - I have a 45' tower with TH6DXX, 6m and 2m yagis. I could easily >> string a makeshift inverted L with about 45' vertical and around 100' >> horizontal. This I could string up in a few hours. the Horizontal portion >> would be pointed south. Not the best of configurations but that's what I >> have to work with. ... >> >> Tom >> W3TA _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Topband: Coil 3.77 software
Coil 3.77 is now available replaces coil 3.72 http://ham-radio.com/k6sti/coil.zip Jim VE7RF _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Temporary antenna suggestion for 160
Mike, I think the problem with elevated radials in 4 squares is the mutual coupling and the necessity that the radial current and impedance be equal. Otherwise the pattern is distorted. Having measured my 8 125' elevated radials there is a significant (>2:1) current imbalance in them due to several factors - towers, trees, buildings, stuff in the ground, etc. I modeled this by having 8 sources in the radials of the measured currents. My modeled pattern skew is about 1db, so I am a bit skeptical of the CW for exactly balancing radial currents for a monopole vertical. (see also N6LF modeling of half circle radials). After calibrating (essential!) my MFJ RF clamp on ammeter, the measured antenna current and sum of radial currents were equal within 2%, so the choke worked. The MFJ can only measure amplitude. Someday I will investigate how the current phase is different in each radial referenced to the vertical. Has anybody done that? Grant KZ1W On 12/21/2019 17:10, Mike Waters wrote: Hi Frank! Thank you for sharing this experience. This is interesting, because (as you are probably aware of) no less a guru than N6LF published results showing that with a single antenna, four ??/4 elevated radials were nearly identical in performance to 120 on the ground. This is true *only* if RF was prevented from either flowing into the lossy earth *or* back along the feedline shield (thus detuning the elevated radials, since the shield would try and act as a radial and couple to the lossy earth). Was anything connected to ground at the feedpoints? And what type of coax feedline choke unun did you use at the feedpoints? Perhaps there are factors in an array vs. a single vertical that would explain your results, but I can't think of any. 73, Mike W0BTU On Mon, Dec 16, 2019, 3:04 PM wrote: Hi Mike, Years ago my 4-square transmitting array used "gull-wing" elevated radials sloping 45 degrees from the feedpoint at ground level to about ten feet high. When I replaced the radials with sixty 120-foot radials laid on the ground I had to shorten the verticals by about five feet to maintain resonance, suggesting that the current at the bottom five feet -- or so -- of the verticals was attenuated by the sloping radials in close proximity to the verticals. As an aside, the performance of the array improved dramatically... 73 Frank W3LPL -- *From: *"Mike Waters" *To: *"thoyer" *Cc: *"topband" *Sent: *Monday, December 16, 2019 8:52:41 PM *Subject: *Re: Topband: Temporary antenna suggestion for 160 CORRECTION It was just pointed out to me that I neglected to mention that the feedpoint on my 160m inverted-L was much lower than 10 feet high! The tuner sits on the earth, and the two wires go straight up from that to the insulator block holding the antenna and the radials, which is less than 4 feet high. From that point, the two radials angle upwards at roughly 45?? (?) to nearby trees, and level out at 10' high to the North and to the South all the way to the ends. (The South radial zigzags back and forth since the distance from the base to the neighbor's fence in that direction is less than 1/4 wavelength.) I had photos of it online, but w0btu.com crashed. Looking for a place to upload it to. I hope this makes sense. Sorry for the lack of details below. 73, Mike W0BTU On Sun, Dec 15, 2019, 8:22 PM Mike Waters wrote: Do the inverted-L, but use at least two 10' high 1/4 wave radials. Do NOT use an RF ground rod, or any radials on or near the earth. Just connect the coax shield to the junction of the radials and any remote tuner. At that point a good choke balun is necessary. Leaving out the choke or grounding the shield will result in very poor performance. 73, Mike W0BTU On Sun, Dec 15, 2019, 7:04 PM thoyer via Topband With only 9 more to go for DXCC on 160 and all of the recent posts about how good the band has been recently "best in years) I find myself with no antenna for the low bands and cringing after each post on how good the band has been. ... Options - I have a 45' tower with TH6DXX, 6m and 2m yagis. I could easily string a makeshift inverted L with about 45' vertical and around 100' horizontal. This I could string up in a few hours. the Horizontal portion would be pointed south. Not the best of configurations but that's what I have to work with. ... Tom W3TA _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Temporary antenna suggestion for 160
Hi Frank! Thank you for sharing this experience. This is interesting, because (as you are probably aware of) no less a guru than N6LF published results showing that with a single antenna, four λ/4 elevated radials were nearly identical in performance to 120 on the ground. This is true *only* if RF was prevented from either flowing into the lossy earth *or* back along the feedline shield (thus detuning the elevated radials, since the shield would try and act as a radial and couple to the lossy earth). Was anything connected to ground at the feedpoints? And what type of coax feedline choke unun did you use at the feedpoints? Perhaps there are factors in an array vs. a single vertical that would explain your results, but I can't think of any. 73, Mike W0BTU On Mon, Dec 16, 2019, 3:04 PM wrote: > Hi Mike, > > Years ago my 4-square transmitting array used "gull-wing" elevated > radials sloping 45 degrees from the feedpoint at ground level to about > ten feet high. > > When I replaced the radials with sixty 120-foot radials laid on the ground > I had to shorten the verticals by about five feet to maintain resonance, > suggesting that the current at the bottom five feet -- or so -- of the > verticals > was attenuated by the sloping radials in close proximity to the verticals. > > As an aside, the performance of the array improved dramatically... > > 73 > Frank > W3LPL > > -- > *From: *"Mike Waters" > *To: *"thoyer" > *Cc: *"topband" > *Sent: *Monday, December 16, 2019 8:52:41 PM > *Subject: *Re: Topband: Temporary antenna suggestion for 160 > > CORRECTION > > It was just pointed out to me that I neglected to mention that the > feedpoint on my 160m inverted-L was much lower than 10 feet high! > > The tuner sits on the earth, and the two wires go straight up from that to > the insulator block holding the antenna and the radials, which is less than > 4 feet high. > From that point, the two radials angle upwards at roughly 45° (?) to nearby > trees, and level out at 10' high to the North and to the South all the way > to the ends. (The South radial zigzags back and forth since the distance > from the base to the neighbor's fence in that direction is less than 1/4 > wavelength.) > > I had photos of it online, but w0btu.com crashed. Looking for a place to > upload it to. > > I hope this makes sense. Sorry for the lack of details below. > > 73, Mike > W0BTU > > > On Sun, Dec 15, 2019, 8:22 PM Mike Waters wrote: > > > Do the inverted-L, but use at least two 10' high 1/4 wave radials. > > > > Do NOT use an RF ground rod, or any radials on or near the earth. Just > > connect the coax shield to the junction of the radials and any remote > > tuner. At that point a good choke balun is necessary. > > > > Leaving out the choke or grounding the shield will result in very poor > > performance. > > > > 73, Mike > > W0BTU > > > > > > On Sun, Dec 15, 2019, 7:04 PM thoyer via Topband > > > wrote: > > > >> With only 9 more to go for DXCC on 160 and all of the recent posts about > >> how good the band has been recently "best in years) I find myself > with > >> no > >> antenna for the low bands and cringing after each post on how good the > >> band has been. > >> ... > >> Options - I have a 45' tower with TH6DXX, 6m and 2m yagis. I could > easily > >> string a makeshift inverted L with about 45' vertical and around 100' > >> horizontal. This I could string up in a few hours. the Horizontal > portion > >> would be pointed south. Not the best of configurations but that's what I > >> have to work with. ... > >> > >> Tom > >> W3TA > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: CQ 160 Contest Rule Changes
Plaques??? Did someone say PLAQUES? While the CQ 160 is indeed a fine contest - we should note that the upcoming Stew Perry Topband Distance challenge also has plaques. Has N2NT's wife sponsored a plaque? I think not!! Here is the current list: SponsorPlaquePaid AA4XX Top Score, Multi-Op World QRP Paid Boring ARC Top Score, Vintage Station, Single-Op Low-Power pre 1963 TX and RX Paid Dawn Tyree Sunrise Award, Top Score, Single-Op World High-Power, limited to two hours prior to sunrise Paid EI2CN Top QSOs, W/VE/XE with EI/British Isles 2019 + 2020 EI4HQ Top Score, Single-Op High-Power Europe Paid K1EP Top Score, Operator < 21 years old Pending K5WA Top # Grids, Single-Op minimally directional antennas (TX and RX) Paid K6ND Top Score, Single-Op World (K6SE Memorial) Paid K7CA Top Score, Zone 22 Paid K7CA Top Score, Zone 24 Paid K7FL Top Score, 100% Search-and-Pounce Paid K7RAT Top Score, Single-Op High-Power, Southern Hemisphere Paid L1AR - Dr. Beldar Top Score, Single-Op, Temp Antennas Paid KL7RA Top QSOs, Single-Op Paid N4YDU Top Score, Single-Op Low-Power USA Paid N7GP Top # NA Grids, Single-Op Zone 25 Paid N7UA Top Score, Single-Op, High-Power World Paid N9TF Top Score, Single-Op USA Low-Power, Multiband vertical, non-resonant, tuner in shack Paid N9TF Back yard special (Top Score, Single-Op Low-Power USA, < 4500 Sq Ft lot, < 35' high random wire) Pending NQ6N Highest score from working LP or QRP stations Pending VE9AA 2001 A Space Odyssey - Single-Op Score closest to 2001 points Paid VK6GX Heroic Tropical QRN Fighters, Top Score, Single-Op +/- 15 degrees latitude Paid VK6VZ Flying Doctors of VK Baseball Cap for Top Score, Nothern Hemisphere working Southern Hemisphere Paid W1KM Top Score, Single-Op Scandinavia Paid W2GD Team Top QSOs, NA/SA by EU Station Paid W7RH Top Score, Asia Single-Op Low-Power Paid WA6CDR Top # Grids, N5IA Memorial Paid If you would like to add another plaque to this list - please contact t...@kkn.net in the next 7 days. 73 Tree N6TR Temporary Plaquemeister - Boring Amateur Radio Club On Sat, Dec 21, 2019 at 7:16 AM Andy Blank wrote: > Happy holidays everyone. > > Please check out the rules page for the upcoming CQ160 Contest in 2020. > There have been some changes, mostly for the better I hope. > > These include: > > Low Power is now limited to 100W only. > Assistance is allowed in QRP category. > Single Op Low Power now has both Assisted and Unassisted categories.. > > Some language has been changed to make things clearer, and to be uniform > with other CQ Contest rules. > > Please also check out the PLAQUES that have been sponsored. > There are some plaques that are not yet funded, and we are looking for more > sponsors. Any additional categories can be offered as well if you have an > idea. > Send me an email and I will forward to K1DG our plaque manager, who can > arrange it for you. > > > Rules here: > https://cq160.com/rules.htm > > Plaques here: > https://cq160.com/plaques.htm > > 73, Andy N2NT > Director CQ160 Contest > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Topband: CQ 160 Contest Rule Changes
Happy holidays everyone. Please check out the rules page for the upcoming CQ160 Contest in 2020. There have been some changes, mostly for the better I hope. These include: Low Power is now limited to 100W only. Assistance is allowed in QRP category. Single Op Low Power now has both Assisted and Unassisted categories.. Some language has been changed to make things clearer, and to be uniform with other CQ Contest rules. Please also check out the PLAQUES that have been sponsored. There are some plaques that are not yet funded, and we are looking for more sponsors. Any additional categories can be offered as well if you have an idea. Send me an email and I will forward to K1DG our plaque manager, who can arrange it for you. Rules here: https://cq160.com/rules.htm Plaques here: https://cq160.com/plaques.htm 73, Andy N2NT Director CQ160 Contest _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
