Jeff Janock - AJ2U wrote:
> Now am focused on
> ensure the neighbors are all appeased due to some rfi/tvi
> issues... turns out some of my spurious emissions are not
> down far enough. rig is ts940 and 10m is a mess! Found out
> my low pass filter (old b&w) was doing NOTHING to help.
> recommendations for low-pass filters?
Good morning Jeff,
I also run a TS940 and had TVI complaints when operating on 10m.
It is a special problem in New Zealand, because the second harmonic
of 10m falls in the middle of Channel2, which carries the main news
programs. I live in a weak signal area, and found that if I
used my GDO on 56 MHz a few m-watts would destroy my TV pix.
Steps to overcome my problem were:
1. Install Bencher YK-1 L/pass filter. This is the best performer
of the resonably priced filters, and is rated at 1.5Kw continuous.
This eliminated interference to all houses except the immediate
neighbour on my boundary.
2. Install a Pi-type antenna tuner. This took out the residual
harmonic content. Note that a T-match does not seem to reduce
harmonics.
3. If using a directional antenna you may observe that the
TVI is present only when the antenna is pointed at a particular
house. Try to use directions where the antenna does not
illuminate the house where you have had complaints.
Using these methods I was able to operate with a linear on
20m and 15m, and barefoot on 10m. Unfortunately you may
not have eliminated telophone and audio interference, but that
is another story.
Regards,
Martin ZL1ANJ
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