[TowerTalk] Lightning Arrestors

[Doug Rehman]

---snipped---
> From: jimlux [mailto:jimlux at earthlink.net]
> > I have far more Polyphasers in service since new ones are often
> available on
> > eBay for a steep discount.
> 
> Just curious, why do you think that is?  Is it some sort of marketing
> approach from PP?  I would readily believe that PP's "factory direct"
> price is greater than the retail store price (PP wants to encourage
> their retailers and distributors, so they protect their pricing)


The "C0" (HF) Polyphasers are not that common on eBay but do appear from
time to time. The "C1" (VHF/UHF) Polyphasers are almost always available,
often in lots. The "C3" Polyphasers are somewhat less common than the "C1",
but more common than the "C0". I suspect the reason for the new Polyphasers
on eBay is that many small radio shops have closed up over the past several
years- their inventory winds up on eBay. Also, many state/local governments
have outsourced their communications maintenance with their inventory being
auctioned off. There is likewise a wealth of 800/900 MHz protectors from the
wireless industry and 2.4 GHz protectors from the wireless Internet
industry.



> > This reduced the
> > summertime lightning damage from taking out a station about every
> other week or so to only one or two stations per year.
> 
> Were the damage events from direct strikes or from induced transients
> from nearby strikes?

Usually direct strikes to the tower (remember, it's Florida)- the power line
and phone line protectors seemed to mostly eliminate problems from those
circuits.

> >In an
> installation
> > where static charge is a significant problem, the life of the
> protector
> > could be diminished by the continual firing to dissipate the static
> charge.
> 
> Gas tube type protectors should have almost infinite "fire event" life
> (e.g. a NE2 bulb fires 120 times a second when hooked up to the AC
> line)
> 
> Thyristor based suppressors definitely have limited life.


True, but NE2's eventually fail. I'd rather bleed off the charge than allow
it to build to hundreds of volts before it is dissipated.


Doug
K4AC