...also known as the Archer Sportcraft antenna
I posted something along these lines before. A few days ago a friend of mine wanted to modify his SA-001 to get a bit better glide slope reception. Borrowing from @ewumnrr Martin's good work, I set about making another antenna.
Basically the same dimensions as the SA-01, .025" 2024-T3 aluminum - major dimensions are 1 1/2" wide.
The "base" leg was extended to +20" and a 3/4 flange added to facilitate mounting to the aft wing rib ( W-712-L/R (RV-7), W-1012-L/R (RV-10, RV-14), W-812, W-912, etc.)
The "front" leg was modified to include a 3/16" flange
The "top" leg was extended to +19" and will be trimmed further to get the VSWR < 1.5:1 if needed.
The tuned element / gamma match section measures 5 1/2" inside, all angles are @60° forming an equilateral triangle. The width of the tuned element is 3/4". Lacking fiberglass "pc board" material (FR4) of .063" thickness, I substituted a piece of similar thickness Lexan and ran it the full length of the tuned element.
The tuned element measures about 4" and is held in place with 3 nylon screws/nuts. It includes the glide slope element of 9" long.
In order to tune the antenna, I used a MFJ-259D and NanoVNA-F V3.
I mounted the antenna to a large metal plate to serve as the surrogate for the wing rib -- this is a part of the antenna system, similar to a counter poise / ground plane / reflector. It's size/shape/position relative to the tuned element will affect antenna performance ( impedance, VSWR, etc.).
View attachment IMG_0692.jpeg
I added a little material to the "top" leg to get the VSWR a little better -- I suspect this will change when mounted to the airframe as this leg extends past the test counterpoise.
View attachment IMG_0696.jpeg
Long cable to simulate what will be installed in the RV-10.
I trimmed the glide slope stub until I got down to a reasonable VSWR.
and a workable impedance:
and the obligatory Smith chart -- I can't read it; but it's pretty cool to see it on the screen:
Yeah, I know - white sneakers -- I won't be wearing them after Labor day
I posted something along these lines before. A few days ago a friend of mine wanted to modify his SA-001 to get a bit better glide slope reception. Borrowing from @ewumnrr Martin's good work, I set about making another antenna.
Basically the same dimensions as the SA-01, .025" 2024-T3 aluminum - major dimensions are 1 1/2" wide.
The "base" leg was extended to +20" and a 3/4 flange added to facilitate mounting to the aft wing rib ( W-712-L/R (RV-7), W-1012-L/R (RV-10, RV-14), W-812, W-912, etc.)
The "front" leg was modified to include a 3/16" flange
The "top" leg was extended to +19" and will be trimmed further to get the VSWR < 1.5:1 if needed.
The tuned element / gamma match section measures 5 1/2" inside, all angles are @60° forming an equilateral triangle. The width of the tuned element is 3/4". Lacking fiberglass "pc board" material (FR4) of .063" thickness, I substituted a piece of similar thickness Lexan and ran it the full length of the tuned element.
The tuned element measures about 4" and is held in place with 3 nylon screws/nuts. It includes the glide slope element of 9" long.
In order to tune the antenna, I used a MFJ-259D and NanoVNA-F V3.
I mounted the antenna to a large metal plate to serve as the surrogate for the wing rib -- this is a part of the antenna system, similar to a counter poise / ground plane / reflector. It's size/shape/position relative to the tuned element will affect antenna performance ( impedance, VSWR, etc.).
View attachment IMG_0692.jpeg
I added a little material to the "top" leg to get the VSWR a little better -- I suspect this will change when mounted to the airframe as this leg extends past the test counterpoise.
View attachment IMG_0696.jpeg
Long cable to simulate what will be installed in the RV-10.
I trimmed the glide slope stub until I got down to a reasonable VSWR.
and a workable impedance:
and the obligatory Smith chart -- I can't read it; but it's pretty cool to see it on the screen:
Yeah, I know - white sneakers -- I won't be wearing them after Labor day
