It sounds like basic RF overload of that preamp. Does the interference
arise when transmitting on other bands? Are antennas for other bands as close
the TV antenna/preamp?
First I'd try some ferrite on all the leads to the preamp - input, output,
power (if not fed up the feedline). Several turns or more around each ferrite
You might also try some common mode suppression, in the form of two 300 ohm
twinlead to coax transformers connected back to back.
In a message dated 7/3/2008 11:23:32 A.M. Eastern Standard Time,
Lots of great assistance already, thanks!
Here are some additional clarifications ...
1. The interference is on all TV channels, VHF & UHF.
2. Removing the distribution amp eliminates both my
desirable TV signal and the 6M interference.
3. I presume that my Yaesu FT-857D is not sending
TV frequency signals to my homebrew delta loop
so it must be that the distribution amp is picking
up 6M along with the weaker TV signals and amplifying
them all together.
Therefore, I am guessing that I need a 6M trap filter
just prior to the TV distribution amp. so it has nothing
on 6M to amplify.
Where do I find such a critter? Or are they fairly
simple to build?
WDAYT? (What Do All Y'all Think?)
> I raised my delta loop *from* a feedpoint of 6'
> above the ground *to* 15' and now it is getting
> into the TV (all channels).
> The TV antenna is at 30 feet and is about 30'
> from my 6M antenna. (I am running 100W SSB.)
> I have disconnected the outside antenna at the
> distribution amp inside the house and used an
> amplified set-top antenna - no interference then.
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