Geoff's right. The easiest way to reduce power is to use more coax. The
data is in the back of the Dick Smith catalog. If I remember correctly the
spec for rg-58 is 16.1 db loss per 100 meters of line at 100 mHz.

If you're just going to use it as a link then you could also drop the
output a lot and use directional antennas. That would minimise
interference as well.

There is another possibility that I haven't tried, and maybe some has and
can comment. That is to use one of the good quality a/v senders that use
the 2.4 gig (free) band. There is one made by Digisender that lets you use
directional, external antennas and will cover a good distance.

John

On Thu, 14 Feb 2008 09:13:39 +1300, Geoff Barkman <barknet@...>
wrote:
> Probably the cheapest/way to reduce power is to add attentuation to the
> aerial lead.
> Add length to the cable... not sure of exact figures but adding 10
> metres to aerial lead will lower output power.
> Or make a 3 resistor wire network to reduce power. At a guess you need 3
> - 5 db of attentuation on your transmitter.
> Any amateur radio club or RT installer should be able to give you the
> appropriate values to use. The ARRL (American Amateur radio league)
> published stuff in their hand book about this.
> Modifying your transmitter is tricky because it could upset the internal
> tuning of it... making it unstable. Also make sure there is no external
> controls for adjusting power... not sure how adding aerial attenuation
> fits into this rule.
> Cheers
> Geoff Barkman
>
> Michael Rowse wrote:
>> Heya guys,
>>
>> Anybody got any bright ideas on how to reduce the signal coming out of
>> the back of the transmitter? We have a one watt transmitter but wish
>> to reduce it down to approx 300mW so as not to interfere with another
>> close station. (we are going to be using this TX as a link system)
>> Would some kind of attenuator do the trick or is there another method?
>> The cheaper the better.
>>
>> Thanks in advance
>> Mike
>>
>>
>>
>> ------------------------------------------------------------------------
>>
>>