Does antenna cable length make a difference?

[avee8tor13]

Folks,

It there a standard length the com, nav and GPS antenna cable length must meet?

Thanks kindly.

[CESSNADON]

There is not a standard length.Rule of thumb, make the cable as short as practical as the cable does create signal losses, though they will be slight for typical lengths.

[Bill Dicus]

Have heard that the antenna for the WAAS GPS (Garmin 430 in my case) needs to have a minimum length. Anybody know if this is true and what that length is? Thanks in advance. Bill

[jsharkey]

The COMM antenna on my -6 is on the belly just behind the pilots seat so the feed line connection is in the under floor gap. For access I have a cover plate screwed to the floor. To avoid too tight a bend in the co-axial cable I installed a right angle adaptor from Radio Shack. Will this cause any significant loss - or would I be better living with the tight bend?

Jim Sharkey
RV6 Tip-Up
O360-A1A Fixed Pitch
Day/Night VFR
On the last leg - I hope!

[mannanj]

There's no standard length, except that as I recall the Garmin 430-530's require a minimum of 13 ft.

I would recommend RG-400 over the cheaper RG-58, unless something special is specified by the mnfr.

[CESSNADON]

Severe bends are not good. A severe bend will stress the insulation and the termination to the connector. I would use a good quality "right angle" connector. Check some of the eletronic supply houses such as Allied, Newark Mouser and there are many more for the connector. I believe that you will find a higher quality of connector there.

[mannanj]

Originally Posted by CESSNADON

Severe bends are not good. A severe bend will stress the insulation and the termination to the connector. I would use a good quality "right angle" connector. Check some of the eletronic supply houses such as Allied, Newark Mouser and there are many more for the connector. I believe that you will find a higher quality of connector there.

Jim:

Radio Shack adapters cause about a 3db (up to 50%) signal loss. There is a difference between an "adaptor" and a "connector". The right angle connectors mentioned above are installed the same way as a regular BNC though they end in a right angle.

Digi-Key.com in Minn. will have them too although they have a $25.00 Minimum

They are beyond the $3.00 price range though, but are well worth it.

[jsharkey]

Many thanks
Jim Sharkey

[SteinAir]

It actually depends on individual units. But, the GNS-430W does have a specific minimum for the GPS....if you don't follow it then it's very likely your GPS might not even work at all. I get a LOT of phone calls from people claiming their new 430W can't find the GPS signal, only to find out that their 3' cable is WAYYYY to short.

My recommendation, follow what it says in the install manuals for each specific unit.

Cheers,
Stein

[az_gila]

Originally Posted by SteinAir

...

My recommendation, follow what it says in the install manuals for each specific unit.

Cheers,
Stein

...a VERY GOOD suggestion.....

More builders should try it....