Draker
Well Known Member
The recent "how many GPS antenna" thread reminded me that I always had this question in the back of my mind but never actually asked. I have a bunch of those little black "puck" antennas on my glare shield, all from Garmin: three GA 26C antennas for GPS and one GA 24TNC for SiriusXM. At some point during my build, I think I read somewhere that the lengths of the cables are important, so I left them alone. They are so close to the instruments though, that there is a lot to bundle up:
Yuck!
Is there a definitive source of information about whether it is acceptable to cut these down to a nicer length and re-crimp new connectors? Garmin's GA 26C manual doesn't say anything about shortening, but does advise a special extension cord if you want to lengthen. Their GDL 51 manual has a short note in a table caption:
Which hints that the length of the cable is important, but doesn't add much for laymen. I work in cell phone technology but I still consider RF and antennas to be voodoo. Is there an actual reason not to mess with the length of these cables, or is it an old wives' tale I picked up somewhere?
Yuck!
Is there a definitive source of information about whether it is acceptable to cut these down to a nicer length and re-crimp new connectors? Garmin's GA 26C manual doesn't say anything about shortening, but does advise a special extension cord if you want to lengthen. Their GDL 51 manual has a short note in a table caption:
For each 1 dB gain over 24 dB, add 1 dB of attenuation into the antenna cable path between the antenna and the GDL 51R/52R. Note that gain specifications are defined at the output of connector for some antennas, e.g. GA 24 TNC. Additional attenuation will be required for any modifications made to the cabling to these external antennas.
Which hints that the length of the cable is important, but doesn't add much for laymen. I work in cell phone technology but I still consider RF and antennas to be voodoo. Is there an actual reason not to mess with the length of these cables, or is it an old wives' tale I picked up somewhere?