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Antenna wire: amount

Stockmanreef

Well Known Member
I assume that I should probably use the following cable wire for the comm and gps:

RG-400 M17/128 Rf Double Shield Coaxial Cable

How much would I need? A rough guess. 30 ft?

thanks
ken
 
Get double plus 25% of what you need .. so when you cut it 1 inch too short you don't have to pay shipping again :D

Seriously ... don't forget enough to learn how to install the connectors, order extra connectors to train with, and leave enough for service loops in case you have to re-terminate later to troubleshoot.
 
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Just to add to what Control has suggested, it also depends on where those antenna will be located.
As a reference, my GPS (two of them) antennas are in the wingtip as well as my VOR. The TXPDR and remote radio are behind the baggage compartment and I believe I bought 100' and used majority of it.
 
well, the transponder antenna cable comes with the empennage kit. It is interesting that that does come with the kit while the comms do not. I have a gtx 45, which has one antenna for both the ADS-B and the transponder. ALso, I think that I have a gps antenna for the EFIS that came with the panel. I wil have to verify.

The VOR antenna will come with a wire. I plan to go with the whiskers in the vertical stabilizer and I can get antenna with the cable.

So it is just the 2 comms under the seat and the GPS on the top of the empennage. Steinair suggested 60'. I was thinking that was overkill.
 
Does a VOR antenna use coax cable? like:

RAMI AV-532L VOR ANTENNA WITH CABLE

the picture on ACS with cable shows wire ends that don't look like cable terminal.
 
Wire

I am building a -10...

G3X touch with XM so:

GPS antenna for GTN 650
GPS antenna for GDL51R
XM antenna for GDL51R
Com 1 antenna
Com 2 antenna
VOR/LOC antenna
Transponder antenna

I asked Steinair, they said buy 100 feet. I did and have used most of it...:eek:
 
I've gone though about 80 ft

A few do over's from cutting cable short, redoing end terminals (buy extra) >

Rv14A

Some of these receiver GPS info via serial connection:
GDU 465 w/XM
GDU 470
GTN 650
GTX 345
GTR 200
G5

Archer ant in wing tip
2 GPS ant on top of empannage
2 bent whip comms on belly
Trnspndr ant on belly
 
Unless you find a great deal from a source that you will not be using in the future, I recommend that you measure and order just what you think you will need.

I ordered most of mine from Aircraft Spruce and Stein Air. There are numerous opportunities to order more wire when you order other items and then save shipping costs. I think that I have placed more orders with Aircraft Spruce than any other vendor in my life. I use the wishlist on their site. Just keep adding items to it until I can justify the shipping costs.

This wire costs $3/foot. I know that you can use cheaper styles of wire for certain uses but I just used the 400 for all.
 
should I add a doubler plate for the transponder antenna?

did anyone find that the coax cable that Van's supplied with the empennage kit to be too short by a foot or so? It is supposed to run from the back of the tail cone to the panel. It does, but not any extra. Turns out it is not long enough to reach my GTX 45R. If I put it behind the center stack it would have been enough, but I have something else there. So it looks like i will be rerouting to the antenna to the port under the baggage area.

Not a huge deal. Just means that I have to climb into the tail cone and clip all the cable ties and then run the cable where I want it. sort of a PITA, but low on the list of annoying things thus far in the build.
 
Make sure you want the transponder antenna there for sure before you do that to save a few dollars on coax. The rear mount already has the doubler in place and it's always best to keep the distance between all of your antennas as much as reasonably possible. I also didn't like that there was an antenna pretty much underneath the passenger seat connected to a high output device that is transmitting constantly compared to a regular comm. the nice feature of the GTX 45R is it only needs the one antenna so you don't have to use that hole on the passenger side.
 
just a royal PITA to rerun the cable. It is just the little annoying things that Vans does that irritates me. I would have preferred not having the cable run at all versus it being too short. I would gladly have paid an extra $5 for another ft of coax on that line. Now is is complete useless, unless I put the antenna under the baggage area.

I do see your point and I will probably rerun the cable if I have enough.

If I had figured this out prior to running the comm coax, I could have just cut it in half and used them for the comm antennas. At least then I would have been able to reuse the connectors already in place.

I wonder if the time to build a plane is based on the second build and not the first. I definitely could build the plane in a lot less time the second time around knowing all the BS that I could avoid.
 
Garmin recommends a relatively short distance for the ADSB antenna cable for my 45R. The location under the baggage compartment meets it; the location in the tail does not. It might be ok in the tail, but. I shortened the Van's supplied coax to the baggage compartment antenna location and reused the rest for comm antennas under the seats. I put a dummy transponder twig antenna in the tail to fill the hole. :cool:
 
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I wonder if the time to build a plane is based on the second build and not the first. I definitely could build the plane in a lot less time the second time around knowing all the BS that I could avoid.

I was just thinking this the other day, I could build another so much better and more quickly too!

Another option is to just put an extra 2 feet in line with an extra male and female BNC connector pair. It will of course add some nominal loss but I would bet for this purpose it would not be of any significance.
 
there is no recommendation for the length of the coax from the 45R other than is has to be at least 3 ft from the unit to prevent RF interference.

The manual also stated that the transponder antenna be at least 3' from any other com antenna and I don't know what that means--the base of the antennas or the tips.

Garmin indicated that the position in the back of the plane is fine for the transponder antenna.
 
Where to start

When you start running your coax cable. Start with the longest one first, then get smaller. That way, if you cut it to short, you can use it in the next shorter one. You can alway make them shorter, but you can not go back and make it longer.

Good luck, and yes, practice with the connectors. Solder the tip, and don't crimp the tip. Also check them out with an ohm meter before you do the final sleeve crimp, just in case you have a short. You can still fix it then and not waste a connector.

Brian
 
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I already crimped several of the tips. What solder? SteinAir video says to crimp. The tip is held in place with the connector and can't slide through (at least with the connectors I used).

I just posted in the "gotchas" thread about the coax provide with the empennage kit. The length of the wire allows the transponder unit to only be placed behind the subpanel in the center stack area, which is very limiting. I put the GTX-45R behind the copilot G3X. Oh, well.

I cut the end off and pulled a longer piece of coax through. Unfortunately, I already ran both comm coax lines as well as the GPS line. Now I have a 15' piece of coax with nothing to do with it--$45 down the drain. I would have gladly paid an extra $3 for a coax cable 1 ft longer with the original kit.
 
there was a coax cable provided with the empennage kit--unless it comes with one of the other kits. It runs from the transponder hole in the tail cone to the panel (see 10-23--WH-00014). From what I understand, the phone wire runs to the ELT. At least my ELT has no way to connect a coax cable.
 
There is also (or should be) a coax to connect the tail-mounted ELT with the antenna in the baggage compartment.
 
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