I need schooled on antennas

[JohnR]

Okay, I'll admit it I know next to nothing about my antenna needs. Can you guys help me out? I would like to get them bought so that I can do some doublers similar to the one CJ posted but need to get the antennas so I know what size and the hole spacing etc.

I found this discussion, http://rivetbangers.com/cgi-php/forums/ ... .php?t=633, but would really like more detail.

I believe I want GPS, 2 comms, at least 1 ILS/VOR, transponder and a beacon. What else do I need?

I also want them all to work as well as possible and do not believe I want wingtip antennas unless someone here can convince me that is what I need. Oh yeah, ELT antenna needs to go somewhere also. Man this thing is going to look like a porcupine!

Where is Wisconsin Willie when you need him? Doesn't he make his living working on avionics? He's probably off to Florida or somewhere golfing.

[smittysrv]

I'm glad you're asking this question, John. Me too, me too! I'll feel like Bones on Star Trek.

$%^it Jim, I'm a programmer, not an electrician!!

[Spike]

I did have a friend of mine place his VOR antenna in his wingtip with great success. It might be worth looking into.

[svanarts]

Wingtips are a great place to hide VOR antennas because they are normally oriented horizontally. Doesn't do so well for the comm antennas because comms want to be oriented vertically. Some have hidden their comm antennas in their gear leg fairings but you will get a shadow from the steel gear leg itself. Here is what I did;

I put my single comm antenna on the belly of the plane just forward of the main spar carry through. I have had ZERO problems with communications.

I placed my transponder antenna on the centerline of the belly of the plane about 4 feet aft of the comm antenna (don't want them too close.) Again, no problems.

My elt antenna is inside the cabin fastened to the rear seat bulkhead and sits vertically next to the rear seat passenger. I've seen others who have mounted the ELT antenna under the empenage intersection fairing.

My GPS antenna was mounted to the top of my roll bar. I've seen others mount these on the glareshield and also others how mount them to the inside of their upper cowling, close to the firewall. I would try to keep the GPS antenna inside of the cabin if at all possible because it's a cleaner, cooler environment.

[JohnR]

Thanks for the info Scott. I may go with the VOR in a wingtip as it sounds like it works well and one less thing hanging out for some little kid to swing from. I seem to remember someone on a website making the VOR for the ingtip but must not have book marked it. Anyone else seen this?

This is about as quiet as I've seen this group. I thought I would get a few more opinions on this. Several views but only a couple of responses. Smitty and I need some help. Right Smitty?

CJ, what are you using for antennas? I know you put in a couple of doublers. How about the transponder? Anyone have a recommendation of the blade or the little shorty I can get off of Ebay for under $20 shipped?

[captain_john]

So far I have read no lies on this thread! Everyone is right on the money. I am kinda bummed because everyone KNOWS how I THRIVE on confrontations!

Right Spike?

John, I DID end up going with the Comant ones on the other thread. I ended up putting two on the belly. Comm 1 on the left, Comm 2 on the right.

I also got the XPDR antenna off Ebay for $20 just the other week! It looks good and should be fine.

I bought my wingtip antenna from Spruce a long time ago. It is a bit overpriced for what it is, but there is some engineering involved to get it to market sooooo, pay the piper to call the tune.

The GPS antenna(s) will tuck under the fiberglass and the 406 EPIRB/ELT will be longeron mounted behind the roll bar.

Hey Willie, am I all right? Is my plan sound?

John, does this sound reasonable?

CJ

[captain_john]

OH YEAH, here is the link to my antenna doublers if anyone was wondering.

http://rivetbangers.com/cgi-php/forums/ ... php?t=2516

...and the marker beacon will be a 40" stripped piece of coax, probably in the other wingtip.

This will leave me the two big Comms and the little stubby XPDR whipping in the wind. THAT'S IT!

Not bad for all that stuff, I think.

CJ

[smithhb]

OK, here is my plan. COM 1 (Comant CI-122) on belly beside gear mount just forward of spar. COM 2 (Comant CI-122) on belly beside gear mount on the right side.

Bob Archer NAV antenna in the right antenna and Archer Marker Beacon antenna in left wingtip.

Transponder antenna beside right fuel vent just aft of firewall.

[JohnR]

Thanks CJ. Sounds reasonable to me but I don't know anything about antennas. Looks like you put both your whips right across from each other on the belly. Is that enough spacing or does it matter? How did you decide on placement? I can tell from your photos on the other post about how far back you placed them, I just like to know the reasoning behind it before doing things.

Can you tell me which Comant model are you using? Where did you pick up the Comant? It sounds like what I want from what I am finding in my research.

I'll get a stubby XPDR from Ebay, looks like I can't beat it for the price.

That 40 inches of coax, any secrets to that? Is 40 inches the correct length? How precise does it need to be? Do you glass it in the full length?

Ill check out the wing tip antenna. I see Van's sells one and will check out some of the other normal sources. I just figure I might as well get this stuff out of the way.

[smithhb]

John,

I found that Skygeek.com has the best prices on all antennas, however, Steinair.com is great for answering all your technical questions. Call Stein or Jed and talk with them. I am having them build my avionics harness and cut my panel.

[captain_john]

I did put them across from each other. THEY say you need 36" of spacing between them. I have that and then some.

I thought they looked good there, were high enough off the ground for obstacle clearance and it is an ideal place for talking to ground based transceivers from a lofty perch, as they reflect downward if placed on the belly.

I have 2 CI 122's. They have a good reputation.

I wanna say the 40 marker beacon thing I read about on Dan's site. It is a receive only antenna and most anything will do. You strip the shield away and 'glass it in as I recall. Simple as that.


CJ

[captain_john]

Bret, I just pinged Skygeek. $150 is their price and I think that is what I paid at Spruce while at OSH. Free shipping, of course.

CJ

[captain_john]

Here is a link to Dan's site where he mentions the Marker Beacon antenna.

http://www.rvproject.com/20030611.html

CJ

[Spike]

John,

I believe the make of the VOR antenna you are referring to is Bob Archer's. I have an article he wrote up in the Document Share.


John

[TomC]

Hi John,

Here's what I have on my plane.

Comm radio - CI-122 mounted under the seat pan on pilot side of the plane. Will be adding a second radio/antenna with antenna on passenger side. The first has always worked great.

Transponder - 1 Ted antenna below is a link to it. mounted between the two comm antennas. This has never been a problem.

http://www.aircraftspruce.com/catalog/a ... ponder.php

Nav radio - 1 Archer wingtip antenna Has always worked great but don't use much.

My GPS antenna is on the "dashboard" This has worked fine.

My ELT antenna is mounted to a siderail behind my seat. I have it tied in a half loop so it does not rub on the canopy. Don't know if it works or not

Good Luck!

[JohnR]

Thanks to everyone for helping me figure out what to buy. Between the comments here and researching online I went ahead and made the jump. So far I have ordered 2 Comant CI122's and one of the TED shorties. I plan on getting a wingtip also but don;t need it yet. Actually I don't need any of them yet but want to get the stiffeners built for the comms so figured I might as well go ahead and get both the Comants while I was at it. The TED was so cheap I got it out of the way also.

Thanks again!