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

["jrusgrove@comcast.net" <jrusgrove@comcast.net>]

Stan

 

If you're planning on using this mast as the radiating element on MF and especially LF with any appreciable power, egg insulators will be problematic. The relatively small physical separation with normal moisture and 'contaminents' will carbon track. I've had good luck using black delrin rod ~ 6 - 10 inches in length with holes drilled in each end. Countersink the holes to remove the sharp edges.   

 

Jay W1VD  WD2XNS  WE2XGR/2

 

 

----- Original Message -----

From: Stan, W1LE <stanw1le@verizon.net>

Reply-To: <rsgb_lf_group@blacksheep.org>

To: <rsgb_lf_group@blacksheep.org>

Sent: 9/7/2018 3:45:48 PM

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, wa3tts@verizon.net 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 <stanw1le@verizon.net>
To: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
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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