Moving a Antenna

[C Fischer]

 

I would like to move the COM antenna mounted in the center of the windshield.  It functions fine but I'm not a fan of how it looks.  Its mounted on the little strip between the two access panels to the panel.  Would anyone no where I could come up with that little strip if I move the antenna or should I just fabricate a new piece.   Any suggestions on removing the headliner to run new coax, tips or tricks?  I would prefer to change the antenna to the "7" style of antenna so help locating one of those would be awesome.  I've got 35 hours in this new to me Mooney and I'm in love except that dang antenna  Thanks for any help
 

[EricJ]

The 7s haven't been made for a long time and many haven't aged well.   I have two of them that are still holding up, but I'd suggest something else.   If the one you have works, consider just moving it.    An avionics shop or ham operator with a VNA or VSWR meter can check to make sure it's healthy (not corroded inside, cracked, etc).

 

[PeteMc]

What @EricJ said.  When's your next Annual?  Maybe just have them move it then.

If they don't have an avionics guy there that can test your old antenna, you might want to consider just getting a new one.  You're going to need a new cable for the length, so a new antenna will not add that much to what you're already paying for the cable and labor. 

And assuming they pull the side panels for corrosion inspection, then that bit of labor is already included in the annual's cost.  And if they do not normally pull it for the C, then maybe it's not a bad idea anyway.

[Jim Peace]

I had the same issue and waited for an annual and they fabricated a new strip.  Also at that time I had a new headliner put in and while it was off all new scat tubing in the ceiling....that antenna will cost you a lot of money with the other stuff to do...

I beg you to not do the math,, just enjoy.....

[carusoam]

Oddly… wasn’t that where the thermometer used to reside?

Expect a prior owner (PO) didn’t like Jimmy’s advice above….

There is going to be a price to go with antenna moving…

How do you feel about ceiling removal?

There may be some work required for installing the wires….

Plan in advance of all the things you want to see and do…

Make sure the ceiling drain is working and refresh its tubing while in there…

PP thoughts only, not. Mechanic…

Best regards,

-a-

[PeteMc]

About the ceiling removal...

I'll add another consideration to what I said earlier.  I knew my interior panels were on their last legs for a while now and narrowing in on where to have the interior done.  But during the panel upgrade and Annual, the pilot side panel was so brittle it finally disintegrated into about 30 pieces when they tried to take it out.

So depending upon the condition of your interior, you may need to be prepared to find new panels/parts.

[Yetti]

Consider the dual GPS/ VHF antenna.   If you have a GPS then replace.   If not run GPS coax while you are there.   Consider running it down the starboard A pillar

[Old Chub]

 

"Consider the dual GPS/ VHF antenna.   If you have a GPS then replace.   If not run GPS coax while you are there." 

I did exactly as Yetti is saying (and I too had an antenna in the middle of my field of view same location as C Fischer describes) by removing the antenna ahead of the windshield and replacing my GPS antenna with a combo GPS/COM so I didn't add any more holes.   I was fortunate as the antenna in front of the windshield was a single whip and I just put a botton plug over the hole when I removed it.   The GPS/Com antenna is located above the baggage compartment where the old GPS antenna once was.  Both features work great on the new antenna.  I only had to make one new run of coax for the com side of the new antenna. 

 

[Jim Peace]

What is this GPS/COM combo you guys are speaking of?

Link?

[cctsurf]

6 hours ago, Jim Peace said:

What is this GPS/COM combo you guys are speaking of?

Link?

https://www.aircraftspruce.com/pages/av/antenna_gps/CI2480200.php

for example.

[jamesm]

It depends on the  radios  setup that  you have? 

the   CI 2480  if I recall correctly is a non WAAS GPS/ com antenna  where as  the CI 2580 is the WAAS GPS/ Com.  I have  both on my '67C

and of course have a GPS/COM antenna is quiet a bit  more pricey.

 

Edited June 28, 2021 by jamesm

[EricJ]

7 hours ago, jamesm said:

It depends on the  radios  setup that  you have? 

the   CI 2480  if I recall correctly is a non WAAS GPS/ com antenna  where as  the CI 2580 is the WAAS GPS/ Com.  I have  both on my '67C

and of course have a GPS/COM antenna is quiet a bit  more pricey.

 

That's weird.   It's not clear at all what the difference is between the two antennas (CI 2480 vs CI 2580) based on the spec sheets.   The VSWR for the 2580 is slightly better but its Noise Figure is slightly worse.   The gains are potentially the same, and the frequency specs are the same.    It looks to me like a 2480 could work for WAAS potentially as well as a 2580.    They claim the 2580 meets the WAAS Gamma 3 specs, without saying what the difference is.  

[jamesm]

You are probably correct. When I installed Garmin G5 the early Installation manual revisions. One of the antennas that the manual called out was for the ci 2480. i thought I had read some where that It was a non WAAS gps. Not sure where I saw that though.