Topband: Detuning shunt fed towers

[Tom W8JI]

>> With an Amphenol Type "HN" connector there is never any flashover.
>> SO-239's did not cut it. Type "N" is even worse.



>A UHF connector won't flash over at 1500 watts if the VSWR is low.
>
> Dave WX7G


HVN connectors will hold off about 5000-6000 volts peak. I used them a lot 
in high power plasma stuff. They have good lightning immunity, the pins are 
the weak part.

dry UHF connectors of reasonable quality and proper install will hold off 
5000 volts peak voltage. They work fine, but people ordering plasma stuff 
normally won't consider them. They are pretty resistant against lightning, 
usually the male shell fails from holes blowing in it where it contacts the 
inner male connector part.  The females almost never fail.

good-quality properly-installed dry type N connectors will hold off about 
3000 volts peak. I consider them low SWR 2500 watt connectors, and they are 
very prone to lightning damage.  The pins are too weak. I modify the surplus 
cable I buy to change from type N female connectors to a UHF female. It 
takes about 15 minutes on a lathe to change a Heliax female N to female UHF, 
and they last a whole lot longer in lightning storms.

properly installed dry BNC's will hold off about 3000 volts peak. They are 
junk for lightning immunity. They have poor mating ground connections and 
poor pin size. I use them as infrequently as possible.

I can't imagine arcing a properly installed UHF connector with a 
transmitter, unless peak voltage gets up to several KV.  That would take a 
pretty high impedance at the connector.