Lynn Coffelt wrote:
I have just seen a range of low-loss thin ad flexible 50 ohm coax -
aircell 7, ecoflex 10, ecoflex 15. If its as good as it claims to be,
i would be great for use on boats for both HF and VHF. Has anyone used
it?


Yup, great stuff. Not as flexible and thin as RG-58, but a lot more than
RG-213 (?).


As an installer and repairman, we used foam dielectric coax once in a while
for cell phone antennas because of UHF loss problems. It isn't as durable as
RG-213 (the standard for most installations around salt water, as it crushes
and flattens easier than solid dielectric.

There were some brands of foam dielectric coax that absorbed moisture that
degrades coax very quickly.

RG-58 is ok for short runs of 25 watt VHF, but in tall masts, it just
doesn't cut it. Also, it is a little light weight for 100 watt plus HF
installations.

The obvious weak link in most masthead installations is in the PL-259 coax
connector installation. There are not many out there who can do a proper,
watertight soldering job up at the top of a wavering, windy masthead. Been
there, done that, was not always proud of my work.

Old Chief Lynn, W7LTQ, PG-13-20604


Hay, chief, did ya ever think to push the wire down the mast using a
messenger to guide it, like the old wire being replaced, or a fish
line? that way, you leave the end with the on deck pre installed
connector on it at the top and outside the mast with a drip loop*,
while you cut to length and terminate the bottom end below decks, or
at the mast base, an easy job, or at least not so awkward as at the
top of a wobbly mast, which you heel a bit to guide the messenger.
(Damn! dropped the flux, again;-) Is the soldering iron plugged in?)

I once climbed to the top of a big fir to cut off the top for a
Christmas tree, but dropped the axe after I got up there. Had to go
down and up three times all together, once just to get my arms,
which fell off next!

If you were a masthead radio tech, and not proud of your work, you
would have done it again, unless it was your own life at risk.
Cobbler's shoes? Dija ever go up just to unscrew, remove and then
rescrew the connector, then wait for a radio check after pulling
gently on the feeder? It could benefit from doing it once every year.

How long do hams spend sending? Rael hams use code, light duty
cycle, to set up fax, etc, with old contacts. Or do they want full
duplex stereo video to remote studios, at 450 megs using meteor
scatter at days' ends, with gigantic yagis doublesteered at the
masthead? I saw one like that, once, on a 40 foot ketch in green
lapstrake on Grand Lake.

Mil RG58 is good enough for most, cheap, light.
Communications is our most valuable resource.

*Note: A typical drip loop style exit from the mast head would
cause compression of the dielectric. Soft cable with long heights
hanging should be clamped above the exit hole, sealed with caulk,
double clamped or wirehung to the mast, properly sized and torqued,
No drip loop, unless needed to meet the antenna mount. Masts should
be able to drain at the heel anyway. Matching coils should be below
the masthead, 2"-3" away from the mast. Tilting the antenna a little
to avoid instrumentation is ok, though it may affect directivity at
extremes.

Terry K -Yeah, yeah, we *can* build monster cables. -SofDevCo-