First 160 AM QSO of the 2013/2014 season
W8ACR:
Managed to catch Steve KL7OF on 1925 last night. Band was relatively quiet, and his signal from Tum Tum was good into central ND. This was my first AM QSO on 160 in over a year, and was the maiden voyage for my homebrew rig on 160 meters. I've now made successful contacts on 40,75, and 160 with the big Homebrew rig. Looking forward to the KD0HG memorial heavy metal rally. Two full six foot racks, probably 750 lb. I think I qualify.
Also, I've been doing lotsa antenna work to get back on the lower bands. The system right now consists of a 31ft vertical element topped with four top loading wires each 28ft long. The natural resonance point is about 2900kHz. On 160, I add a base coil and a matching unun; on 75, a series cap and unun; and on 40, an L-network. Currently, there are 72 radials each 65 feet long, and 10 radials each 130 feet long. More radials to come. Rrad on 160 is about 6 ohms, and I get a 1.0:1 SWR at 1925 with a 2:1 SWR bandwidth of 20kHz.
I'm getting very good audio and signal strength reports using the big HB rig.
Life is good.
Ron W8ACR
KL7OF:
Nice signal and audio last nite Ron.......Congratulations...Great Rig.....neat antenna ....The band was quiet....I also worked into southern calif on 1925 last nite. Sigs weren't strong but steady.........
W3GMS:
Quote from: W8ACR on September 27, 2013, 02:40:20 PM
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Managed to catch Steve KL7OF on 1925 last night. Band was relatively quiet, and his signal from Tum Tum was good into central ND. This was my first AM QSO on 160 in over a year, and was the maiden voyage for my homebrew rig on 160 meters. I've now made successful contacts on 40,75, and 160 with the big Homebrew rig. Looking forward to the KD0HG memorial heavy metal rally. Two full six foot racks, probably 750 lb. I think I qualify.
Also, I've been doing lotsa antenna work to get back on the lower bands. The system right now consists of a 31ft vertical element topped with four top loading wires each 28ft long. The natural resonance point is about 2900kHz. On 160, I add a base coil and a matching balun; on 75, a series cap and balun; and on 40, an L-network. Currently, there are 72 radials each 65 feet long, and 10 radials each 130 feet long. More radials to come. Rrad on 160 is about 6 ohms, and I get a 1.0:1 SWR at 1925 with a 2:1 SWR bandwidth of 20kHz.
I'm getting very good audio and signal strength reports using the big HB rig.
Life is good.
Ron W8ACR
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Hi Ron,
Your short capacitive top hat verticals for 160M reminds me of many enjoyable QSO's I had on that exact subject with Dr. Jerry Sevick - W2FMI (SK). Those were the days when we were only allowed to operate over the first 50 kHz part of the band. On top of that, power was also restricted since the band was shared with Loran. Jerry did a lot of experimenting with low loss matching transformers for those relatively short verticals for 160 meters.
Here is some addition information on Jerry:
http://www.arrl.org/news/jerry-sevick-w2fmi-sk
73,
Joe, W3GMS
WA2ROC:
There were several of us (maybe 6 or so) down on 1885 last night and signals were S9 or above for everyone except between me and a fellow 15 miles away.
This group, plus or minus a few, get together at about 7 PM and keep going until we tire out or other reasons. Please feel free to "come on down" and join us.
W8ACR:
Hi Joe,
I have refined the antenna further since the last post. It now consists of a 30 foot vertical section with eight top hat wires each eight feet long. After some mathematical calculations, I thought I had chosen the proper top hat length to resonate the antenna at about 3800 kHz. It actually has a resonant frequency of about 4100kHz, so I was a bit off on the calculations, but I was proud that I came even that close! I shortened the vertical section slightly from 31 ft to 30 ft to gain some mechanical strength. I had considered taking it down again and lengthening the top hat wires, but I chose to stick with what I had because it was quite difficult to get the antenna up and get all those top hat wires untangled and straightened out!
I have a roller inductor at the base that can resonate the antenna at any frequency on 160. The Rrad is about 5-6 ohms on 160 and I match the antenna to the feedline with an unun. On 75 meters, I use just a few turns of the coil, and the Rrad is about 22 ohms. Again, I match it to the feedline with an unun. On 40 meters, the antenna is close to a 1/2 wavelength vertical, but can be matched very well with an "L" network.
I've had several chats with KL7OF on 160 using this new configuration, and it seems to work pretty well so far. We still haven't had great conditions on 160, but the early returns are promising. My next two projects are a 160 meter 1/2 wave dipole fed with open wire line, and a Beverage antenna pointing east. I don't know if you have 160 capability, but if you do, I hope we can meet on the air sometime.
Ron W8ACR
Knox, ND