Topband: protect my transmitter from atmospheric discharges

[Rob Stampfli]

On Mon, May 31, 2010 at 09:57:59AM -0700, sasas asasas wrote:
> Hi. I have an transmitter at 160m band (500w). i know that when the weather is bad, the antenna's wire (inverted L) has a voltage about several kvolts. I would like to protect my transmitter. I am thinking to use a 2.5mH R.F choke (1A max current) which i will connect between antenna's feedpoint and ground system. What do you think about this solution? Some radio amateurs i think that they use carbon resistances. Which solution is better? ( i don't like to increase the swr by adding choke or resistance). Its better to ground the choke or the carbon resistance to my transmitter's ground system or to the public electric corporation ground system? thank you

My guess is that your transmitter should be the least of your concerns.
I'd be much more worried about your receiver.  A good voltage drain will
not only protect your equipment, but also reduce the noise level in your
receiver that arises from the induced voltage.

You may want to take a look at the following:

http://www.iceradioproducts.com/33.htm

Whether you obtain such a product from the manufacturer or roll your
own, the ICE design is a good one.  I've used these their arrestors
for a while now, and have not observed any SWR problems arising from
their use.

Rob