Hello Hugh, Thanks for your comments.

Yes, I have experienced the biological growth on the nylon guys for the masting that supports the RX only wire antennas. I have also noticed discoloring due to the UV along with the heavy biological growth. I also get the biological growth on the black double braided polyester haul ropes on the main towers. In time I will probably try a vinegar soak to remove the biological growth, 5% table strength.

Stan

Hello Stan, W1LE

 

You'll find that nylon is hygroscopic so not the best insulator when wet. 100% polyester is better but of course that's not taking into account dirt and and organic material incorporated over time. I have some polypropylene insulators and use those and ceramic mixed in the installation. The plastic ones support lichen growth which is interesting but not helpful.

 

Rgeards, Hugh, M0DSZ

 

----- Receiving the following content -----

From: Stan, W1LE

Receiver: rsgb_lf_group

Time: 2018-09-07, 20:45:48

Subject: Re: LF: Porcelain insulators on rope guys for a vertical antenna

Hello Mike,

Thanks for your comments.

I have plenty of the egg insulators in stock. I will be sure to have 1 in each guy . Once I get the final version of the vertical up in the air, I hope to keep it there for a couple of decades.

And I will plan to instrument the final install for impedance changes with the weather, and hi-pot.

All of the original 3/16" twisted nylon guys in the set, will be replaced with the double braid.

Here on Cape Cod we have the typical New England weather, plenty of rain, snow, ice, and wind.

Stan, W1LE

On 9/7/2018 1:30 PM, [email protected] wrote:

Stan: For what it is worth, I found a piece of 3/16" nylon covered polyester line removed from my HF vertical after 15 years of outdoor exposure. The line was dry and some dried mold present on the nylon jacket.

My electronic　 megger indicated over 20 Giga-ohms at 2500VDC test voltage, even at 1 inch separation along the line. Then I wetted the line with tap water. Resistance fell to 1/2 megaohm at 500VDC test voltage over a 6 inch span of the line.

Perhaps if you live in the Arizona desert with low humidity most of the year, it may not matter much. Would you rather radiate energy, or use it to dry out your guy lines?　 For the few extra $, I would stick with the guy line insulators.

73, Mike wa3tts


-----Original Message-----
From: Stan, W1LE <[email protected]>
To: rsgb_lf_group <[email protected]>
Sent: Fri, Sep 7, 2018 12:40 pm
Subject: LF: Porcelain insulators on rope guys for a vertical antenna

Hello The Net:

For my vertical antenna guyed in three direction at 4 levels, I am
planning to use 3/16", polyester, braided, of double braid construction.
Original guys were of the military surplus type, part of a GRA-4 antenna
system and part number MX-383A/GRA-4, that uses, 1 each, insulator in line.

For replacement guys, can I remove the insulator and only use the
braided line ?

With wet guys (after rainstorm) I measure the (~ DC) resistance from the
vertical to ground as greater than 6 megohms, my meters capability.

What are your thoughts ?

I can add the insulators, but I would also need to add crimped
connectors or other rope clamps, that would reduce the ultimate
reliability of the guy.

The vertical is constructed of MS-44 aluminum masting sections stacked
up to 50', (maybe 55 or 60'+ later). Final plan is to add a capacitive
top hat with 8 each, 20' radials and a center loading coil for use on
2200M and 630M. Probably a additional switchable base loading coil for
2200M tuning (TBD).

Stan, W1LE　　　 Cape Cod　　 FN41sr





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