[TVI-RFI-EMI] RFI problem

[Ron]

HI Carl,

You seem to be getting a lot of good advice.

I asked my question out of concern that your LP filter was being subjected to
standing waves which can.

1. Cause it not to function
2. Destroy it

1.8 VSWR is okay. A LP and most other lumped component filters should be
used in a flat line that matches the filters input/output impedance. Otherwise
the filter can produce interference.

Of course the filter may not be the problem. I presume you have done tests 
by taking the
LP filter in and out.

If there is an 'improvement' with the filter 'out' then you need to look 
more close at the filter.
Perhaps test or have it tested correctly.

If the problem is overload there is 'nothing' you can do at the source ( 
your station) accept
decreases power ( usually not acceptable to the amateur). If it is overload 
or you suspect its
overload work on one problem at a time and ask for help/ideas from this group.

Interference can be complex - that is - it could be combinations of 
overload, harmonics/spurii -
intermodulation etc - but its not hard - it needs a Sherlock Holmes approach.

As an interference investigator the hardest problem I have is getting ALL 
of the information
(particularly via emial) from the amateur or the complainant.

Give all information - devices effected, when effected, how effected, what 
bands are in use when effected,
times when effected, power levels when effect and on and on and on.

Good luck Carl -
It not hard - it only gets hard when the human relations (with neighbours) 
deteriorates to bricks
over the fence :-)

Regards
Ron
http://www/radioelectronicschool.com







At 10:24 AM 3/05/2002 -0400, Carl -K8AV wrote:
>Hi Ron,
>
>             The SWR all over the tri-bander is low. Under 1.8 to 1. Most
>places it's no higher than 1.4:1.  I don't even use the tuner in my Mark-V.  I
>have a Cushcraft TH-5 antenna that has two driven elm. that make it
>broadbanded.  The low pass filter is between the amp and antenna.
>
>73,
>Carl