Hi Pete, 18 feet is closer to .14 wavelength. Dr. Lawson says with that boom length gain is around 7 dBi with around 11 dB f/b 73, Bob, W5AH --Original Message-- Can someone who has W2PV's book tell
Any 1:1 balun will work. The "custom" balun from Telrex was a 3 wire 1:1. 73, Bob, W5AH A friend has and old but unused TELREX TB6EM tribander that uses a custom balun which is lost. The rest of the
If one directly measures the voltage, current and associated phase angle (in radians) for the 3:1 mismatched line shown below (hard to do on a coax but easy on twin line) then, E x I x Cos Theta(rads
Hi Pete, Ive had experience with cables listed as something or the other "type" cable and have found that quite often physical appearance is the only thing the "type" cable has in common with the ori
If the MFJ works, why bother with the other one? Bob, W5AH Years ago, I made a Lew McCoy tuner (Ultimate Transmatch) using new EF Johnson Air Variables and a nifty new 28 mh roller inductor. I think
Terry, The 402BA manual says the linear loading assemblies for each DE half are approximately 91 1/2" of 1/8" rod. The DE is tapered in 5 segments. DE1 is 1 1/4" X 100 1/16" measured from the center
Measure the VSWR with a different meter and see if the problem goes away Bob, W5AH Greetings, I'm trying to chase down a problem in my antenna system. On 80 and 160 meters, I see a rise in VSWR after
A vertically mounted full wave loop that is rectangular ( twice as high as it is wide) will have a feedpoint Z of around 40 ohms when fed in the center of the short side nearest the ground. Since you
I believe Dick Fenwick, K5RR, had an article on the subject in QST a few years ago. Bob, W5AH --Original Message-- From: towertalk-admin@contesting.com [mailto:towertalk-admin@contesting.com]On Behal
Lets make it two votes for the 402BA. Ive had one up for 13 years and have had no problems with the antenna. I dont know how old it was when I bought it. Bob, W5AH --Original Message-- ///SNIP/// The
Hi Bill, I have used a similar arrangement to what you describe for 15 years of so. The difference is that I added a 4th "guy" just below my lower guy wires. This extra guy is 1/8 " aircraft cable an
Hi Kim, It is not possible to get an accurate F/B measurement (or any kind of pattern measurement)from any rig that has the AGC turned on. Also, the signal must be a constant carrier, not SSB. I am n
Stephanie, Try moving the sloper feedpoint up to the top of the tower and add a choke balun to the feedline if there is not one there already. Also, as someone else said, try adjusting the height abo
I recently disassembled an old Hygain DB1015 that had elements thouroughly stuck together by pouring some hydrogen peroxide over the joints in question. It will loosen or break up the oxidation holdi
Hi Dick, The feedlines to each vertical need to be equal lengths. They do not have to be 3/4 wavelength, however. You can save on coax by using two lines that are equal length and long enough to conn
Can anyone help me identify some ferrite cores I have. Around 10 years ago I obtained a double handfull of toroids for use in baluns. I do not remember who the manufacturer was. The cores are approxi
Can anyone help me with the going price for a Heathkit SA2060 Antenna Tuner? Bob, W5AH List Sponsored by AN Wireless: AN Wireless handles Rohn tower systems, Trylon Titan towers, coax, hardline and m
Hi Tom, Go with the lengths in the manual. I'm not very familiar with the TH6 (I have a TH7), however, experience with yagis in general says that sometimes elements can be shorter or longer than one
Hi Pete, Losses and feedpoint Z add so they are effectively in series. Thats why we quite often see a 1:1 SWR at the base of a vertical over poor ground that has no radials at all or not enough radia
Buy both of them. Ive had both the 100/140 and 200/260 since the 60's and would not be without them. I just checked and my big gun is actually 240/325 Watts. No such thing as a cold solder joint with