[Fwd: Re: Topband: 160 vertical advice needed]

[Herb Schoenbohm]

Dan Levin wrote:

>1)       I will build a 74' vertical out of ~46' of Rohn pushup mast topped
>with ~28' of aluminum stinger.
>
>2)       Add three our four top hat wires at the 60' level to both guy the
>stinger and resonate the antenna.
>
>Dan,  
>

There is no problem with a 4 wire capacity hat but it should never be 
attached below the stinger. It makes the stinger useless. If you run 
capacity hat wires as guy wires be very careful, since they slope back 
down to the ground, not to make the longer than 20-25 feet or else 
unwanted cancellation may occur. If you break up the guy/capacitance 4 
wire hat at 25 feet with insulators and add a perimeter wire all the way 
around connecting all the insulators on the tower side will increase the 
radiation resistance at the tower base.  Also remember to use good 
quality insulators or Phylistran guy from this point down since the 
voltage is high at the junction.  Also try to avoid acute guying 
angles.  45 degrees is OK but less than this is going the wrong 
direction.  You can actually see the radiation resistance go up as the 
angle of declivity is decreased.

Also try to get at least 4 to 8  1/4 wave radials along with the other 
wires on the ground.  I uses inexpensive THN #14 electrical on laying on 
the ground here.

Hope this well help you


73

Herb Schoenbohm, KV4FZ
St. Croix, VI