[Towertalk] Hy=Gain 402BA-S

[Joe Subich, K4IK]

> -----Original Message-----
> From: K7LXC@aol.com
> Sent: Sunday, April 21, 2002 1:00 PM
> To: wfking@worldnet.att.net; towertalk@contesting.com
> Subject: Re: [Towertalk] Hy=Gain 402BA-S
> 
> 
> In a message dated 4/21/02 2:51:43 AM Pacific Daylight Time, 
> wfking@worldnet.att.net writes:
> 
> > I have a HY-GAIN 402BA-S 40 meter 2 el beam. It works fine on 
> > RX and 100 watts TX. However it does not like high power anymore. 
> > Instant SWR infinity with the PA on. Even at 200 watts it appears 
> > to arch over. As long as I run less then 150 watts it's fine.
> 
>     As I recall (I was never an owner), this is the classic 
> failure mode for this antenna. It's insulator failure and arcing. 


You are correct, Steve.  The old Hy-Gain design used the standard 
driven element insulators in the clamshells of the 402BA but placed 
the linear loading between the feedpoint and the elements rather 
than part way out the elements (like the M2, Force 12 and later 
Discoverer antennas).  The voltage across the driven element 
insulators is much too high (ca. 5 KV peak vs. 500 volts)!  

The only solutions would seem to be redesigning the element mounting 
to incorporate better insulators, redesigning the linear loading to 
move it "out" the element (and away from the feed point) or limit 
power with the 402BA!

73, 

   ... Joe, K4IK