[Elecraft] Static rain ?

[Geoffrey Mackenzie-Kennedy]

Deni,

My suggestion is that you use a resistor and not a choke. A choke at some 
frequencies will become a series resonant L-C 'tuned' circuit, and it is 
quite possible that the choke will resonate in or close to one of the bands 
that you use. If that is the case you will loose transmitter power heating 
up the choke, likewise the strength of received signals reaching the 
receiver can be reduced. For static bleeds I usually use 100k 2w carbon 
resistors, the old fashioned type not carbon film, because the resistors 
*must* be non-inductive types.

My K2 survived a lightning strike to my 40m beam, but I think that the 
combination of a coax spark gap out in the garden and an underground coax 
feeder with 'surge loops' took out much of the sting. Back to back diodes 
for protection against overload can create all sorts of intermodulation 
problems if the diodes start to conduct, and for those of us in Europe who 
share 40m with BC stations and using receivers which cannot cope, overload 
is a problem but there are solutions. Please contact me off list if you are 
interested.

73,
Geoff
GM4ESD


----- Original Message ----- 
From: "Deni" <foxfive.vjc at gmail.com>
To: <Elecraft at mailman.qth.net>
Sent: Saturday, December 09, 2006 9:52 AM
Subject: [Elecraft] Static rain ?


>I have recently been plagued by rain static on a new vertical antenna,
> this is a 42 foot vertical fed at the base through an SG230 auto tuner,
> and used on all bands. It seems I need a static bleed of some sort,  a
> choke or resistor. What is the best component to use in an outdoor
> environment?
> My junk box RF chokes look rather puny for this application, the typical 
> small 2.5mH RF choke.
> Would a physically large,  say 1 Meg resistor be more suitable ?
> I thought the auto ATU would in itself provide a static bleed path,
> but apparently not.
> Is the K2 prone to front end damage due to this static charge? I do not 
> have the back to back diodes fitted (to prevent huge signal overload)
>
> Any thoughts, how have you solved this?
>
> 73, Deni
>
> F5VJC