[Mobile-Portable] Iron Horse 40m Ground?

[Dick Flanagan]

At 10:52 AM 7/19/2004, Art Clemons wrote:
 >If you hit something hard enough to bend the spring, you've likely
 >damaged your antenna anyway.  Frankly I'm waiting to hear just what a
 >spring does for an antenna that makes one worth using.

The only thing I've ever used a spring for was to prevent damage to the 
mount or mast.  Any spring that bends when the vehicle is in motion is too 
light!  A good confirmation of this is all the big HF antennas that use 
monofilament guy lines to keep the mast vertical when in motion.

I have moved to non-spring mounts for my Bandhopper and High Sierra 
antennas, but I still use a big spring for a side-mounted mast on my 
truck.  I don't delude myself into thinking that the spring will save the 
antenna, but if I tangle with some tree branches, I hope the spring will at 
least prevent the mount from being ripped out of the side panel.

You will also notice that most base-mounted antenna springs have braid 
inside the spring to provide DC and hopefully RF continuity without 
depending on the coils of the spring, itself.  The strands of this braid 
tend to corrode as they weather, making thousands of tiny dissimilar metal 
diodes, and the mechanical connections at each end of the braid like to 
loosen up with time and vibration.

Small springs to save roof-mounted VHF/UHF antennas from the dangers of 
garage doors are one thing, mongo springs with 3/8"-24 studs are something 
else again.

73, Dick
--
Dick Flanagan K7VC NV SM
E-mail: k7vc at arrl.org