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.
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
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!
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.
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.
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.
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.
Stein's advice is good as usual. The Garmin Upgrade Installation Manual for 400W/500W Series units (mine is 430W) requires that "the coaxial cable have a loss of 3 to 7 dB. If RG400 is used, 3 dB equates to a length of approximately 13 feet of RG400 cable with a connector on each end." Curious that the signal needs to be attenuated a little!? Seems there is no reason to mount the antenna near the GPS receiver. "--antenna coaxial cable must have a minimum of two shields (e.g. RG400 or RG152B). If the existing cable is single shielded (e.g. RG58 or RG59), the entire cable must be replaced..." Also "pigtail lengths for terminating shields at the 400W/500W Series unit are not longer than 3 inches." There are details worth reading in the manual. Thanks, Stein. Bill
