[Boatanchors] Antenna sealing questions, silastic?

[Phil]

Hi All,
Been doing antennas many, many years, but I still have a question, maybe 
2 :)  Yeah, this isn't boatanchors, but there are a lot of antenna 
experts out here.

I just recently installed a TYT TH-9800 (Quad Band clone of the Yaesu 
FT-8900) in both the shack and the Ford "Screw".  Both radios are 
installed and get excellent audio & signal reports.  I don't expect to 
use the 10M & 6M (FM) bands, just got them to use for 2M/440. They were 
only $6 more than the TYT 7800 dual band radios (clone of the Yaesu 8800).

While I ordered the radios I also ordered a new dual band base antenna, 
the Tram 1481 (17 foot colinear).  Supposed to be a pretty good antenna, 
but if I'd read the reviews first I might have chosen a different model 
as some users have had problems with water ingress (sp?), even though 
they said they sealed it well. Others say they've never had a problem 
with it.

Anyway, I didn't think to order coax seal, and RadiosShack is totally 
gone from the Central Valley here in Calif.

The antenna has 3 fiberglass sections that screw together and is 
supposed to have factory seals, which apparently don't do the job.  Many 
folks seal the sections with Coax seal or other methods, and "Silastic' 
repeatedly came up.  WHAT pray tell is "Silastic".  It sounds like 
something a woman might wear.  I sort of thought about heavily wrapping 
the joints with black plastic tape and them put a coat of clear RTV over 
that.  Those are things I can obtain locally.

OR is there something else available at the usual hardware store (ACE, 
Lowes etc) that might be better, especially to seal the coax fitting at 
the base. . .

By the way, the feedline I bought for this antenna is a 25 foot length 
of LMR-400 with factory PL-259's, bought from MPD Digital it looks like 
a VERY good product!  It's my first experience with LM-400, I didn't 
realize it was as stiff as it is. IF I do the install RIGHT it should be 
good for a long time (I'm getting too old to have to re-do antennas and 
push-up poles very often).

We DON'T get a lot of rain here (other than this El Nino year) and seem 
to be in a perpetual drought, but once I put the antenna up I don't want 
to have to take it back down to letthe droplets of water that might 
collect in the bottom dry out.

Are there better ideas here?


-- 
73 From "The Beaconeer's Lair"
Phil, KO6BB
http://www.qsl.net/ko6bb/  (Web Page)

PRESENT RADIOS:
Grundigs: S-350 (~2006), G6 (2011) & S450DLX (2014).
HOMEBREW: 7 Tube+Rect 1v3 Regenerative RX for LF (built 2015)
Icom:    IC-735 Transceiver (~1990).
Icom:    R-75, Cascaded 250/125Hz CW-Filt, Panadapter. (~2009)
Icom:    IC-7200 Transceiver (~2015).
R-Shack: DX-380 digital portable (~1990).
SDRs:    Softrock Ensemble II LF (built from a kit 2015).
          CommRadio CR-1A (~2015)
Zenith:  Royal-7000 Transoceanic Portable (~1968).

ACCESSORIES: HOMEBREW LF-MF Pre-Amp, MFJ-993B HF Auto-Tuner.
              HOMEBREW 8 Hz Audio Filter.

ANTENNAS:  88 foot Long Ladder-line fed dipole, 35 feet AGL for MW/SW.
            Active Mini-Whip, 36 Feet AGL for LF/MW/SW.
            37 foot "Low Noise Vertical", 11 feet AGL for LF/MW/SW.

Merced, Central California, 37, 18, 37N   120, 30, 6W CM97rh