I had earlier asked for opinions about external antenna installation and ultimately decided to go with a RAMI (R.A. Miller), AV-534 L. This is a stainless steel external antenna with eight feet of coax cable with BNC type connector and shield and center condutor solder lugs installed. This is a nicely made antenna that includes all the hardware including an extra set of upper and lower insulators.
My first BC-12D I owned had an external whip, (maybe an ELT antenna by the way it looked), on top of the aircraft and a handheld radio. It had great range and reception.
My L-2B had the RAMI AV-534 antenna mounted on the bottom of the boot cowl. This had a Microair 760 radio and great range and reception.
I decided for ease of installation and range in the air I would install the antenna on the bottom of the boot cowl like my former L-2B.
After consulting with my A&P/IA I constructed a .050 aluminum reinforcement plate that would go inside the boot cowl. After construction it was alodined. See first photo.
After careful measuring I drilled the holes for the antenna and reinforcement plate. I placed the antenna in the middle of the boot cowl, fore and aft and side to side. There is plenty of clearance inside for the antenna at this mounting point. See second and third photo.
See fourth interior photo for reinforcement plate sitting over the holes.
I then marked around the reinforcement plate and removed the paint where the reinforcement plate will mount. This area was alodined. See fifth photo.
Utilizing thinly spread structural adhesive placed toward the center area of the reinforcement plate I installed the reinforcement plate. I had earlier obtained a bolt, two large washers and a nut the same size as the antenna hole. I used this bolt to clamp down the plate while the structural adhesive cured. I also installed four 8-32 x 1/2" stainless steel screws, washer and locknuts in the mounting holes through the boot cowl and reinforcement plate.
Once the adhesive had cured I mounted the antenna using the included hardware. I checked continuity between the plate and boot cowl and antenna shield cable and plate and boot cowl. I also used electronic grade silicone adhesive/sealant around the perimeter of the reinforcement plate to keep any junk and moisture out. See sixth photo.
As my handheld is mounted above the right glovebox, I ran the coax cable up and over the cabin tubing and down the doorpost area, around and under the floor and to the antenna. The eight foot cable that came with the antenna was just about the right length for this installation.
The seventh and eighth pictures show the exterior with the antenna installed. There is eight inches of clearance between the tip of the antenna and the ground. As I personally would not land in grass tall enough to interfere with the antenna there is plenty of ground clearance for my purposes.
This was installed under the supervision of my A&P/IA and the appropriate entries made in the aircraft logbook.
Ground tests were successful and as I am now operating out of class C airspace I had the opportunity to talk to ground, tower and departure and approach, all with no problems. I conducted a couple of quick air tests on 122.80 and 122.70. Both were successful within seconds of my transmitting a request for a radio test. One was over 100 miles away in a bordering state.
I hope this helps anyone who is considering going this route for an external antenna install.
My first BC-12D I owned had an external whip, (maybe an ELT antenna by the way it looked), on top of the aircraft and a handheld radio. It had great range and reception.
My L-2B had the RAMI AV-534 antenna mounted on the bottom of the boot cowl. This had a Microair 760 radio and great range and reception.
I decided for ease of installation and range in the air I would install the antenna on the bottom of the boot cowl like my former L-2B.
After consulting with my A&P/IA I constructed a .050 aluminum reinforcement plate that would go inside the boot cowl. After construction it was alodined. See first photo.
After careful measuring I drilled the holes for the antenna and reinforcement plate. I placed the antenna in the middle of the boot cowl, fore and aft and side to side. There is plenty of clearance inside for the antenna at this mounting point. See second and third photo.
See fourth interior photo for reinforcement plate sitting over the holes.
I then marked around the reinforcement plate and removed the paint where the reinforcement plate will mount. This area was alodined. See fifth photo.
Utilizing thinly spread structural adhesive placed toward the center area of the reinforcement plate I installed the reinforcement plate. I had earlier obtained a bolt, two large washers and a nut the same size as the antenna hole. I used this bolt to clamp down the plate while the structural adhesive cured. I also installed four 8-32 x 1/2" stainless steel screws, washer and locknuts in the mounting holes through the boot cowl and reinforcement plate.
Once the adhesive had cured I mounted the antenna using the included hardware. I checked continuity between the plate and boot cowl and antenna shield cable and plate and boot cowl. I also used electronic grade silicone adhesive/sealant around the perimeter of the reinforcement plate to keep any junk and moisture out. See sixth photo.
As my handheld is mounted above the right glovebox, I ran the coax cable up and over the cabin tubing and down the doorpost area, around and under the floor and to the antenna. The eight foot cable that came with the antenna was just about the right length for this installation.
The seventh and eighth pictures show the exterior with the antenna installed. There is eight inches of clearance between the tip of the antenna and the ground. As I personally would not land in grass tall enough to interfere with the antenna there is plenty of ground clearance for my purposes.
This was installed under the supervision of my A&P/IA and the appropriate entries made in the aircraft logbook.
Ground tests were successful and as I am now operating out of class C airspace I had the opportunity to talk to ground, tower and departure and approach, all with no problems. I conducted a couple of quick air tests on 122.80 and 122.70. Both were successful within seconds of my transmitting a request for a radio test. One was over 100 miles away in a bordering state.
I hope this helps anyone who is considering going this route for an external antenna install.
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