[BC] Long Wire

[Mike McCarthy]

I think the size of the drape wire is/shoule be more determined by the
length of the skirt, limits of the supporting structure, and need to
sustain a stable physical relation than outright conductor resistance. For
a lower frequency (say below 800khz), a wire will require suitable tension
approaching that needed for 3/8" line to remain mechanically
(read...electrically) stable across the 350ft. and longer span. Even with
including stabilizing arms spaced 75-100ft. to minimize deflection.

OTOH, a skirt for a 1500 Khz station could be the size wire sold by Nott
(3-#12) and tensioned to something more closely aligned with 3/16 line
(250-300 lbs.)

In my opinion, the use of galvanized wire as the drape wire is not as
desireable as a copper or copper coated wire. As others have noted,
stainless wire is a no-no.

I my cases, the challenge has been finding a distributor of copperweld
with stock in sizes larger than that sold by Nott. Copperweld (the
company) wants a minuimum 1500lb. order. If I knew someone who wanted
1000-1500ft. of 1/4" or 5/16" wire, I would have ordered the minimum lot
and split the cost.

Once I settled on using the wire Ron sells for my latest project, the next
challenge was to find someone who had the correct grips. That said, Ron
Notts's office would do well to stock the grips for the size wire they
sell. And to carry a second larger size (5/16"??) for bigger
installations. The good folks at Preformed Products were pretty good at
steering me towards distributors who have stock on copperweld grips. I
found them on the first call and had 20 of them the next day.

The other parts were secured from Hubbel-Chance's electrical distribution
catalog.

Thus the most difficult aspect of this whole project was locating the 
copperweld wire.  But we eliminated galvanized wire early.

MM

> Exactly! Mike, you could not be more correct. However
> there is a downside to reducing wire size. The smaller
> conductor will have greater DC resistance that will
> translate into somewhat greater loss, but perhaps more
> importantly, it will increase the inductive reactance
> which has implications beyond requiring more capacitive
> reactance to be in the feed.
>
> This is why I contend that 3/8" galvanized guy cable
> is a better choice for drape wires. Back in the day
> (when copper was cheaper) slant wires were often bare
> #6 stranded copper for very much the same reason.
>
> Phil Alexander, CSRE, AMD
>
> -----Original Message-----
>>From: Mike McCarthy <towers at mre.com>
>>
>>I don't see what reducing the wire size will do in reducing
>>the load on the side arms. When the wires load with ice
>>and/or wind, the actual load presented to the arms will be
>>about equal to that of the heavier wire with even a wire
>>1/2 the size.  Tension is tension.
>>
>>If the support arms are bending, they are structurally
>>compromised and need to be replaced with arms more
>>suitable for the application.
>