I may be suffering from a case of too much information, but I'm puzzled by my new 160-meter inverted L, about 60 feet vertical with 8 on the ground radials each about 65 feet long My old inverted L b
Without going into all the feedline details, why not just add the extra wire to the far end of the horizontal portion? If you don't have enough space for all of the extra horizontal wire then I would
Author: Mike Fahmie via TowerTalk <towertalk@contesting.com>
Date: Sun, 19 Dec 2021 16:30:22 +0000 (UTC)
I'm guessing that the coax run is acting as another radial in your ground system. You can test this theory by placing a ferrite or isolator at the antenna end of the coax run.-Mike-WA6ZTY My old inve
I second this idea. Wes N7WS On 12/19/2021 9:11 AM, Wes Attaway wrote: Without going into all the feedline details, why not just add the extra wire to the far end of the horizontal portion? If you d
What I do is use an autotransformer at my antenna to transform the ~25 ohm resistance at resonance to ~50 ohms. This basically takes the feedline out of play. Rick N6RK My old inverted L broke, so I
I hope that's not the case, Mike. There is already a two-toroid common mode choke between the coax and the antenna, wound with RG-400. 73, Pete N4ZR Check out the new Reverse Beacon Network web serv
Another thought. I'm a little short of space between the vertical part of my L and the tower which supports the far end of the loading wire. So I feature it; the feedpoint is capacitive and below 50
Pete, The common mode choke - that's how many turns and what material? For 160 something around 8+ turns & type-31 are the "right" rule of thumb answers. Fewer turns or using (example) a type 43 mat
Based on my research, a lot more turns. http://k9yc.com/2018Cookbook.pdf Pete has received lots of good advice in this thread. I'll add this. Base loading is a bad thing, because it places inductance
He already has the feedpoint Z. "Measuring the SWR and R/X at the base of the antenna with my Rig Experts AA-55 Zoom," If he removes the loading inductance and trims the wire for -j25 (and the R stay
Yup. It's the vertical equivalent of a hairpin match. 73, Dave AB7E If he removes the loading inductance and trims the wire for -j25 (and the R stays around 30) then a shunt inductor of 5.3 uH wil
Thanks, everyone, for a lot of thought-provoking advice. A couple of specific comments. At the base of the antenna I have 2 #31 cores each wound with 12 turns of RG-400, in series. I think that may
You need way way way more radials, around 60 on ground at a minimum, and due to copper cost, keeping them at 40 or even 30 feet is better than a paltry 8 at 65+ feet. Your feed point resistance will
No, R is too high, should read about 19 ohms in a lossless environment. I would improve the radial system to get the impedance lower and then use a 1:2 unun to transform to 50 ohms. 73 Peter, DJ7WW I
Thanks, Rob, but I'm trying to keep things in some sort of proportion. I'm currently redeploying my K9AY (which was down for the summer - yeah, I know it's overdue) and then I'll see about more radi
These guys are right about the radial count, in the absolute sense. But it's a matter of perspective. The difference between 8 short radials and 64 long ones is about 3 dB per N6LF. That's half an
On 12/20/2021 10:11 AM, Jeff Blaine wrote: The difference between 8 short radials and 64 long ones is about 3 dB per N6LF. That's half an S-unit. It's significant, but in the scheme of things, havi