Installing a RAMI comm antenna (Ep26)

[@davidrobins4025]

Always thinking outside the box for a better idea about how to do the job. Thanks

[@justinb8973]

Good stuff man. Never stop these videos, We’re living Vicariously through you.

[@KitplaneEnthusiast]

I can’t wait until I can really get into filming flying videos!

[@generalcanby5847]

I started to mount my Cruzer antenna per Mark's suggestion - makes sense, but after reading a few comments about the "ground plane", it seemed like a center location would at least in theory be better. I wrote to RAMI and they replied that "you should be OK with this installation for most communications, if anything, you may notice reduced transmission range off the side of the antenna with the least amount of ground plane. In an ideal world, you would want about 22 inches (1/4 wave length at COM frequencies) extending outward from the antenna in all directions, however that is hard to do on most GA aircraft". As an aside, RAMI has superb technical support as I have written to them twice now and am getting quick and thorough answers. Agree with Mark they are high quality units and also made in the USA (MI). Mark - I am not sure if you are already aware of this trick, but when you locate your antenna mount holes, a good way for spot on placement is to locate/clamp the backing plate where you want the antenna, then insert a piece of 7/32 inch aluminum tubing and drill through the tubing with a #12 bit. Doing this for all bolt locations will give you perfectly concentric #12 pilot holes that can be expanded to the necessary final size of 7/32 inch. The tubing protects the backing plate from any bit damage during the hole drilling. As always, thank you for these informative and helpful videos.

[@robertbarron1339]

Nice video Mark. It reminded me of one of my favorite lines from a previous video of yours. You were at some sort of fly-in and a buddy of yours asked about the antenna on the top of your Cruzer, you replied (I think you said GPS), and your buddy said, "that's a big one" and without missing a beat continued, "bet you don't hear that too often." I cracked up. What a slice of camaraderie, good friends, and a fun community of pilots. Anyway, since I didn't comment on the original video thought I'd pass along the laughter on this one. Take care.

[@KitplaneEnthusiast]

Yes I remember the comment you are referring to. He is very quick witted!

[@richardmiller630]

For your antennas/lights, did you consider installing an access panel in the area you want to have the piece, and then mounting the piece in the center of the access panel? That way, if you need to fix the piece, all you have to do is remove the access plate which will remove the assembly. Then you can easily work on or remove the piece from the outside of the plane. Also, if you need to replace the part with one that has a different hole configuration, you would only need to create a new access panel to mount the new one.

[@KitplaneEnthusiast]

I did not. The antennas on my Cherokee were 51 years old before they needed replaced. I think I’ll be good with these ones!! Also, making another plate to mount on the top of the fuselage is one more large area for water to get in.

[@keen1994]

Wow. Always going. 110% outstanding!

[@Patriot-bn9om]

Nice job pointing out the importance of the ground plane for the VHF antenna. The 118-136.975 MHz (19 MHz wide) VHF aviation radio band asks a lot from the typical 1/4 wavelength aviation antenna. At the center of the band 127.5 MHz, the antenna length should in theory be about 22 inches, at 118.0 MHz 23.7 inches, and at 136.975 only 20.5 inches for a perfect match with no reflected transmit power. Most aviation antennas are designed for the center frequency and the specifications read something like 2.0 : 1 SWR (Standing Wave Ratio) or less. Frequencies farther away from the center will have a higher SWR and higher reflected power. The center frequency is likely 1.0 : 1 with zero reflected power. At 2.0 : 1, that means that 10% of your transmitted power is lost, reflected back to the radio where it becomes heat. The more expensive antennas may have some type of matching circuit that makes the SWR better across the band. But, the kicker is, for any of this to even be true requires not just a good ground but a good ground plane. The metal fuselage is part of the antenna. So, the outer braided shield of the coax to the antenna needs to be well grounded or through the connector to metal at the base of the antenna. And that metal needs to have a radius as close to the length of the antenna as possible to get the maximum effectiveness. I've seen fabric covered airplanes with no metal ground plane at the antenna, instead just a little jumper wire to the frame "to ground it". So, they may have had much more reflected power back to the radio each time they transmit, limiting their communication range while also eventually damaging their radio's transmitter by on-going heating. Sorry for the monologue but correct antenna mounting is important. Thanks for pointing it out.

[@larrywhiteley6374]

Great idea for reinforcement .. Merry Christmas

[@gregorygehrke1850]

Merry Christmas, Mark. I hope Santa brings you everything on your list.

[@mattinsley1721]

Hey...Merry Christmas Mark. Really enjoy your channel. Love your thought process. Good stuff.

[@smellyallen]

Yours came with a template and installation hardware. Mine came with with some bubble wrap..... no hardware, no template, nothing except the box and bubble wrap. Bought 2 from Aircraft Spruce, but the box says Rami and was sealed so I don't think it makes a difference.

[@johnreed8872]

Thanks Mark... I don't think I would be satisfied with the supplied doubler either. Nice installation!

[@MRJSWORKSHOP]

Nicely done ⭐️⭐️⭐️⭐️⭐️

[@LTVoyager]

What thickness was your doubler material? It look pretty thin in the video, but it is hard to tell. Most recommend at least 0.040” and often 0.060” or so is recommended.

[@danielbasovitch5087]

Is there any reason you did not mount the antenna dead center of the fuse? It would have better "Ground Plane " effect.

[@telliott100]

Mark, A few episodes ago you introduced us to the edge forming tool. I just watched the Rudder Build video and the guys at Zenith do not edge form their edges. But when I saw your edge formed piece, it was much, much nicer and looked way better. Should every piece of sheet metal edge which overlaps another piece of sheet metal be edge formed? Thank you and I hope you have a good Christmas tomorrow!

[@homertalk]

Not centered? Did you consider the center?

[@KitplaneEnthusiast]

No

[@Capitaine.Albator]

Nice! 👍🏻✌🏻🇨🇦

[@AnonyMous-jf4lc]

First!

[@jaideld1]

Why do you keep calling it L angle when both sides are the same length. To be correct it would be V angle. But as its bent its just called angle and not channel or box section or tube for round section as would be described for other profiles

[@johnreed8872]

Got any constructive questions?