Pigtail at base of used mast?

[RenoHuskerDu]

Howdy, I recovered a tower and mast from a local FD who went to 800mhz. The mast will house my 2m and GMRS repeaters. The mast appears to have a pigtail coming out of the bottom. I cleaned it all up, removed the screws you see, and tugged but the fiberglass mast appears to be solidly glued to its metal base sleeve. I peered up in there and see no connection, just strain relief. It looks like a 16" pigtail.

I looked for masts with pigtails for sale just now and didn't see any. Is there such a thing? I'm used to seeing an 239 up in there, accessible by unlocking set screws and moving a sleeve up or down, putting on your 259, then covering it up out of the weather.

Pics below. As for a UHF conx, there does seem to be a 239/259 hidden under that rubber seal at the end of the pigtail. The seal is very robust, even after years in hot Texas sun. I don't know what product was used but I want some. Strong waterproof sticky rubber tape? Anybody know what it's called?

 

[mmckenna]

That's not a mast, that's the antenna. Pretty common for commercial antennas to have a whip coming out of the bottom like that. That would be used to connect to the Heliax coming up the tower. Usually normal/non-Superflex heliax is too stiff to connect directly to the bottom of the antenna.

As for the sealer, that's often butyl tape. You can buy coax seal kits that come with that, as well as the 2" wide vinyl tape used under it and as the outer cover. You can often find those kits pretty cheap on eBay.

 

[mmckenna]

Times Microwave WK-S-2 - Weatherproofing

WK-S Weather Sealing Kit

theantennafarm.com

RFS CTAPE2-1 Weatherproofing Tape

Self bonding silicone weather seal

theantennafarm.com

Commscope 11316

COMMSCOPE vapor wrap connector sealant. 3" x 50' roll. Approximately 3/16" thick. . .

theantennafarm.com

Commscope 11317

COMMSCOPE vapor wrap connector sealant. 15 pcs - 3" x 4", 15 pcs - 3" x 8". Can be Black or Gray in color .

theantennafarm.com

ANDREW 221213 BUTYL WEATHERPROOFING SPLICE KIT COAX CABLE CONNECTORS COMMSCOPE | eBay

A NEW ANDREW 221213 BUTYL WEATHERPROOFING KIT COAXIAL CABLE CONNECTORS PVC. THE ONE YOU WILL GET IS SIMILAR IN CONDITION. ONLY THE ITEM PICTURED IS INCLUDED. IF IT IS NOT PICTURED, IT IS NOT INCLUDED.

www.ebay.com

 

[mmckenna]

and for good measure, here's the common industry standard installation guidelines for sealing outdoor coaxial cable connectors:

https://www.telewave.com/wp-content/uploads/2016/12/TWDS-0502.pdf

Be wary of anyone that tells you it's not necessary, or that just a layer of electrical tape is "good enough". That just means they haven't been doing this long enough to see what happens when it's not done correctly.

 

[RenoHuskerDu]

That's not a mast, that's the antenna. Pretty common for commercial antennas to have a whip coming out of the bottom like that. That would be used to connect to the Heliax coming up the tower. Usually normal/non-Superflex heliax is too stiff to connect directly to the bottom of the antenna.

As for the sealer, that's often butyl tape. You can buy coax seal kits that come with that, as well as the 2" wide vinyl tape used under it and as the outer cover. You can often find those kits pretty cheap on eBay.

It does all seem to be one unit, yep.

There is a whip that went on top, about 55cm. Wouldn't that make it high 400s full wave? It's broken off, alas.

 

[RenoHuskerDu]

and for good measure, here's the common industry standard installation guidelines for sealing outdoor coaxial cable connectors:

https://www.telewave.com/wp-content/uploads/2016/12/TWDS-0502.pdf

Be wary of anyone that tells you it's not necessary, or that just a layer of electrical tape is "good enough". That just means they haven't been doing this long enough to see what happens when it's not done correctly.

Even in my life of fixing non-antennas, I've learned how short a lifespan electrical tape has. It's a 2 year solution, at best, in exterior application. In a protected space like a pickup truck interior, quite a bit longer but not permanent.

Thanks for the tips and links.

 

[mmckenna]

No idea, I wouldn't guess from just seeing those photos. Someone else may recognize the antenna type/manufacturer.

 

[mmckenna]

Even in my life of fixing non-antennas, I've learned how short a lifespan electrical tape has. It's a 2 year solution, at best, in exterior application. In a protected space like a pickup truck interior, quite a bit longer but not permanent.

Thanks for the tips and links.

Exactly.
A great installer I knew used to wrap the final product with the 2" wide tape, then follow up with a coat of Scotch-Kote sealer. That sealed everything well.

Big issue I run across with electrical tape is those that think grabbing the roll and stretching the tape until it breaks is the right way. That stretches the vinyl, but not the adhesive. Those always unravel in short order. Using scissors/razor blade will result in much better outcomes.

Or, just use marine grade heat shrink and never worry about it again.

 

[merlin]

Agree this is the antenna itself. As is, it looks to be UHF, however, if there was a 50 some od Cm whip above that, I would think it is UHF.
A vertical coaxial array.
As for weather sealing outdoor connectors, specifically 'N' type but should work for PL259 type.
I have always packed the connection with Dow-Corning #4 compound.
My latest install, I did not have the Andrews weather kit (my preference) so, I did a double wrap of vinyl electrical tape then a generous coating of 'Flex-seal'. The last check with a VNA after 5.5 years, no change at all in the diagnostic response.

 

[prcguy]

The antenna construction and clamps look like Laird FG series.

 

[buddrousa]

I have seen some old Antenna Specialist Antennas from the 80's and 90's that look just like this one in both 150Mhz and 460Mhz.
They were built like the 21 foot 10Db Station Masters but had the pigtail where the Station Masters did not have the pigtail.