Top band DX-ing is real ham radio challenge. 160m is also referred as the "Gentleman's band"...
160 meters - DX-ing on the Edge...

Duben 2008

Antennas inspiration - part III.

17. dubna 2008 v 21:47 Antennas

Double-L antenna 160/80m by K2KQ

Don Toman, K2KQ
A popular misconception about vertical antennas for the low bands is that they must have elaborate ground systems. Here's a vertical antenna for 80 and 160, fed with a single feed line that is simple, effective, and requires no ground system. You won't beat the 4-squares, but you will hold your own against a grounded quarter wave with ridiculous amounts of copper in the ground.
Rather than get into the theory of why this antenna works, I will simply describe it here and let results speak for themselves. If there's a demand, I'll do a follow-up article on the relevant theory.
The antenna is a center-fed half-wave vertical with about 70 feet of vertical length with the remainder of the top and bottom of the antenna bent horizontal and parallel to each other. The antenna looks like a squared-off letter "C" fed in the middle of the vertical part.
Thus, the 160-meter antenna is a 270-foot dipole fed in the center with the bottom antenna wire bent parallel to the ground about 10 feet off the ground and the top at 80 feet off the ground. The horizontal parts are 100 feet long and parallel to each other.
The 80-meter antenna is a 130-foot dipole, fed in the center with 70 feet vertical and 30 feet horizontal 10 feet off the ground and 80 feet off the ground.
Think of it as an inverted L fed against an L. The two Ls are balanced with respect to each other and because the currents in the horizontal sections are out of phase, the antenna has a minimum of horizontal radiation.
The 80 meter and 160 meter antennas are separate, fed from a common coaxial feed line.
In my case, the 80-meter and 160-meter horizontal sections are about 30 degrees apart. The 160 horizontal wires run east while the 80 wires run east-northeast.
On both bands, the bulk of the current flows symmetrically in the center of the antenna, with the current peak about 45 feet off the ground at the feed point. On 80, the current loop peak is about 0.16 wavelengths above ground and on 160, the current loop is about 0.08 wavelength above ground.
The accompanying figure illustrates the antenna.
You can adjust the resonance of the antenna by adjusting the lengths of lower horizontal sections. The small asymmetry doesn't bother anything. The center impedance of mine at resonance is very close to 50 ohms on 160 and close to 70 ohms on 80. The 160 antenna presents high impedance at 80 meters and the 80-meter antenna looks like a parallel capacitor across the 50-ohm 160 antenna. The 160 antenna covers 1800-1860 with under 2:1 SWR. I needed to take about 2 feet off the horizontal section to get mine resonant at 1830. If 80-meter current flows in the 160 antenna, it tends to flatten the current loop in the vertical section.
The 80 meter antenna is resonant at 3750 with the 130-foot length shown. The VSWR is under 2:1 over the DX part of the 'phone band. It needs to have some length added to cover the CW portion. I haven't tried to bring it to resonance in the CW band, but have chosen to feed it through a tuner.
I originally had this antenna hung from trees. This year I put up an 80-foot Rohn-25G with three sets of guys. I hung the wires from ropes attached to the tower so they are separated from it by about 3 feet. The coaxial feed line comes off perpendicular to the antenna and is then taped to the tower. The center conductor goes to the top and the shield goes to the lower part. Before the coax turns on to the tower, I've wrapped some 30 feet of it into a coil. I expected to see a lot of interaction, but the tower and guys seem well off resonance at the operating frequencies and I didn't see any to worry about.
The first QSO on 80 was VK6LK, long path on SSB at sunset on September 12. I've worked a few ZSs, HF0POL, LU, and the usual Europeans. On 160, the first QSO was KP4SN on September 15. In the couple of weeks since hanging it from the tower, I've worked ZS6UT, TU2MA, TL5A, VK6VZ, VK6LK, VK3ZL and NL7Z and the usual horde of Europeans on 160 with no fuss. I run about 800 watts out from a Ten-Tec Centurion.
Last January, I had about 200,000 points with 750 QSOs in the CQ WW CW 160 contest using the predecessor hung from trees.
73, Don K2KQ
Well with permission of Don, K2KQ I am sharing an article about this Double-L antenna usable for 160m band. Unfortunatelly its impossible to install this antenna for Topband on my garden as there is no way to errect 21m tall vertical section. Maybe some of shortenning of the vertical parts will make me chance to test it also.
I pretty sure that it can help to lot of Topbanders solve their antennas troubles on pocket size garden but with enough tall tree.
73, Petr OK1RP
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KH6CC Jack...SK

17. dubna 2008 v 19:23 Home
KH6CC Jack SK ..
KH6CC, Jack Wheeler passed away on April 9, 2008

Jack was one of my best friends on topband, a special person for me. The first 160m QSO with Jack was around 1970 when his call was yet KH6CHC. Since then we have worked several hundred times.
Also the first time I visited Jack was mid 80's and since then I visited him so many times.
He was 88 years old while he started ham radio at the age of 13, so he kept working for 75 years !

I guess Jack was the second 160m DXCC holder while Mike VK6HD was the first in Oceania.
He said his 160m DXCC was 215 countries and would complete WAZ with one more zone.

Many thanks Jack. Rest in peace. We all will miss you on 160m.

73, Aki JA5DQH / KH7A
R: Jack KH6CC, L: Aki JA5DQH/KH7A
160m AMP. 450TH x 2 built 60'
Base insulated 100ft Vertical w/100+ elevated radials and Matching box
KH6CC 160m Vertical
(Original published on Topband reflector mailing list by Aki JA5DQH / KH7A)
RIP Jack,
73, Petr OK1RP
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Which antenna for receiving You are using on Topband?

10. dubna 2008 v 22:07 | Petr, OK1RP |  Operation topics
Hello,
as I am receiving lot of emails regarding the receiving antennas, which types are used by high-end Topbanders etc. I decided to try prepare the pool "Which antenna for receiving You are using on Topband".
I guess it can be very usefull for all of us and it can be great inspiration which RX antenna is good in different places. So do not hesitate to put Your correct vote please. If You are using other antennas then do not hesitate to put vote for others and put specification in comments below...thank You.
73, Petr OK1RP
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Japanesse night on Topband

4. dubna 2008 v 12:55 | Petr, OK1RP |  Band reports
Hello all,
maybe You remember my article about beautiful night on 160m last year when the band was openned to Japan for long evenning and I heard a lot of JA's with great sigs in OK land.
Well the same "japanesse night" was on 4th Jan 2007 when the band was full of JA's and some other stations from Asia and Far East...
I remember that I tried to work on the band with QRO and barefoot also and I did not found big diferrencies between my 600W output or 100W output into the 200m half-square antenna. I was able to work JA's even with 100W output (using receiving Flag loop and pre-amplifier) as You can see below...
Yes, I know that Shige is not good example for comparison as his set-up is excellent and his sigs comming to EU mostly strong and clear but I am very happy to work him on Topband every time I can hear him.
I got the QSL card from Shige thru bureau last week so I am proud to put it on my blog to show that its possible to work JA's also with barefoot set-up. Yes, as good as possible receiving performance is needed all the time but not in case of Shige...:)
BTW: You can see his QTH and set-up configuration layouted on his QSL card. Nice hill isn't it? ...even tree are sloped :)
Thank You Shige for excellent QSO and hope to work You again on Topband in the future.
73,
Petr, OK1RP
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THE ANNUAL TOP BAND GATHERING DINNER by George, W8UVZ

4. dubna 2008 v 9:40 | Petr, OK1RP |  Home
A SECOND NOTICE REMINDER OF THE ANNUAL TOP BAND GATHERING DINNER AT THE
DAYTON HAMVENTION - STILL HAVE SEATS AVAILABLE. DETAILS BELOW:

All 160 meter enthusiasts are cordially invited to the Topband dinner on Friday evening of the 2008 Hamvention in Dayton. This annual event brings together 160 meter operators from around the world for food, drink and camaraderie.

We will again be at the Barnsider Restaurant - same location as the past two years.

Here are the particulars:

Date: Friday, May 16, 2008

Time: Social Hour 6:15 PM (Cash Bar)
Dinner 7:30 PM

QTH: The Barnsider Restaurant (Near Hamvention Arena) 5202 N Main Street (Route 48 just north of
Needmore Av) Dayton, Ohio (937) 277-1332

Fare: Salad, rolls and butter, dinner entree, dessert & beverage. Choose from Grilled Chicken, Salmon, Pork Chop or Sirloin Beef Tips (selected at the restaurant). This is a plated dinner - not buffet.

Program: Presenters include K9DX on a "Circle 8" rx array and K3NA on the fantastic VP6DX DXpedition.

Cost: US $29 each, in advance. Includes complete dinner, taxes and gratuity. Same price last three years.

Reserve: Via email, snail mail and pay cost in advance to:

George Taft, W8UVZ
271 Parkshore Drive
Battle Creek, MI 49014

Email: w8uvz@arrl.net or w8uvz@voyager.net

Reserve now and pay dinner charge by May 1st. Foreign visitors may pay at the door but need to reserve in advance. Restaurant is spaced limited so reserve ASAP. We will confirm by email or airmail.

We are looking forward to another great gathering of Top Band enthusiasts.

73 George & George
W8UVZ & K8GG
Originaly published on:
_______________________________________________
Topband mailing list
Topband@contesting.com
http://lists.contesting.com/mailman/listinfo/topband
These informations are valid for US Topbanders only I guess but I decided to share it over here to give chance to all of You attending this annual dinner.
73,
Petr OK1RP
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