[UK-CONTEST] Non-conductive guy ropes - follow up

Thu Aug 30 07:27:04 EDT 2012

Keith, Next time you want Marine hardware try UK yachting supplies. An 8mm
316 stainless bow shackle is in excess of £3 cheaper than reliancemarine.
When you buy them by the dozen it adds up. They deal on e-bay but also run a
shop which is easy to contact. 73 Clive GM3POI 

-----Original Message-----
From: uk-contest-bounces at contesting.com
[mailto:uk-contest-bounces at contesting.com] On Behalf Of Kerr, Prof. K.M.
Sent: 30 August 2012 10:41
To: 'uk-contest at contesting.com'
Subject: [UK-CONTEST] Non-conductive guy ropes - follow up

A few weeks ago I asked on the reflector for advice regarding non-conductive
ropes for guying towers. I received a great deal of comment in reply and to
everyone who mailed me off reflector a big thank you. I promised to
summarise what I found out, what happened etc and a few even mailed me to
encourage me to do so. I know many of you will have solved these problems
already but......
The job was to upgrade the two sets of three blue polyprop guys on my P80 to
something a bit more substantial since (a) WOJ had been bending my ear for
years, rightly so, about the inadequate installation I had and (b) the new
rotator (OR2800) was much heavier than the old T2X and the planned new
antenna would have a 41ft boom and 7 elements.

Non-conductive ropes
One word sums this up - expensive! Nevada do not stock guy-rope grade
Phyllistran any more. Of the other synthetic ropes out there, dyneema seems
to be the buzz word these days. Parafil is available in the UK but is very
expensive and special splicing ends for providing an anchor for shackles etc
are very very so. Several reflectees mentioned Mastrant (mastrant.com) as a
source of various ropes and fittings. These guys in OK-land (including
OK3FLY and a well known contester, Martin, OL5Y) supply several ropes
including pure dyneema rope and some with a dyneema core and a polyester
webbing outer protective coat (Mastrant D-series). This stuff was more cost
effective that importing Phyllistran from Array Solutions and compared to
the myriad other sources of dyneema rope on the web, and even in Radcom,
easily won out on cost. Their web-site gives comparative data showing
claimed comparison with steel rope. I had steel rope ready for two lower
sets of guys but wanted the top set 
 to be non-conductive. I chose Mastrant D10 (10mm dia) which has, I think,
an 8mm dyneema core and an outer polyester web, making its strength similar
to approx 6-7mm steel.
A UK source for this is Vortex Antennas (vortexantennas.co.uk), though you
can deal direct with the Mastrant guys. I went to Vortex and, to cut a long
story short, a supply problem with D10, led to Steve at Vortex securing me
100m of D12 (10mm dyneema core) for the same price as D10, courtesy of a
kind offer from the Mastrant guys. Quite a good deal for me, though the
fittings then cost more but still a great offer!
Wire grips as used to secure/splice steel rope are not recommended for
Mastrant rope, instead they recommend a fist grip which Mastrant can supply.
These have a greater length/surface area for contact with the rope, the
contact area has a spiral ridge for better bite, yet after full torque grip,
they do not damage the rope. The 12mm versions are chunky bits of hardware.
A series of unbelievable cock-ups by UK couriers led to Steve at Vortex and
the Mastrant guys having a lot of hassle to deal with, but throughout they
were gracious and tried hard to solve the issues. I found them both very
good to deal with, very obliging.

Other hardware
With the three D12 guys and 6 more steel rope guys to fix up, I had an
incredible amount of hardware to source. Turnbuckles of adequate size and
strength, rope thimbles of three sizes, wire grips for 6mm and 8mm rope,
D-shackles................
All except the D-shackles I got from Tecni-cable (sales at tecni-cable.com) -
good quality stuff, prompt service and best all round prices (I think, my
head was spinning with so many alternatives and permutations!) D-shackles I
got from Reliance Marine (http://www.reliancemarine.com/) - best choice and
price. Again very prompt and polite service.
Chris WOJ came through for a couple of days about 2 weeks ago and the job
was done. I'll spare you the story but it all worked out and the result is,
I hope, a more secure tower. The D12 does stretch and I have had to adjust
the rope in the fist grips 3 times so far but I guess that will settle down
and it is a quick and easy job.
Happy to deal with any specific question off reflector.
73 Keith GM4YXI/GM5X

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