22-Apr-2020, 11:36 AM
|
#21
|
Antenna Enthusiast
Join Date: Mar 2016
Location: Beach Park IL
Posts: 318
|
16 Director Mod
After disappointing results adding four elements on to the existing factory antenna (Mod 1), I figured it was time to go for broke. I was already geared up to go further anyhow.
Mod 2. I sacrificed one of the reflectors from one the donor antennas and cut 4 new directors to continue the pattern. So, the last 6 directors are all 21" and spaced 10.5" Without any specific antenna modeling it seemed like like a logical step.
I sleeved the inside of the boom with "U" (technically C-Channel) and laid it on the 3/4" under support which I had left extended on the first mod, I figure it would come in hand and it did. I also fabricated a tab so I could attach the upper support cable to the end. The cable is pulled fairly tight. It is fairly solid and withstood 45 mile an hour winds already.
I wanted to put the boom attachment clamp closer to the center of the antenna but my reinforcements don't allow for that. I'll have to research adjustable beam clamps or, of course fabricate my own.
Testing: So-so results. After several comparative tests, I believe these will be the most consistent results. Maximum delta measured was + 2.84 dB. Overall, it's more like 1.2 dB and at the very end the two patterns seem to blend. RF12 is not in the antenna aim market, it is being picked up from the back of the antenna.
Last edited by bobsgarage; 22-Apr-2020 at 8:53 PM.
|
|
|