[RFI] FW: Interference on TV using 2 meters

Tom Rauch w8ji at contesting.com
Mon Oct 30 08:22:16 EST 2006

> On Sat, 28 Oct 2006 10:33:41 -0600, Tim wrote:
>>There was a ham in our area that was so negative about 
>>cable that he set up
>>his packet bbs station with a 300 watt 2 meter amp to 
>>reach a digi 1/2 mile
>>from his home. Plus it was set up to beacon every 30 
> While I certainly don't condone intentional QRM, when the 
> cable system chose
> to convert TV to VHF frequencies allocated to other users, 
> it assumed the
> responsibility for preventing QRM to and from licensed 
> users (including
> listeners to licensed services). The decision to make that 
> conversion was a
> calculated one based on cost and benefits. Sometimes the 
> optimistic
> assumptions about cost (and the law of averages) catches 
> up with that
> decision.

I agree the Ham should not have been using 300 watts to 
access something 1/2 mile away, but the problem with TVI was 
100% the cable operator's creation.

When a licensed over-the-air service operating on assigned 
frequencies causes a problem with a system that is supposed 
to not be receiving over-the-air signals because of problems 
with the closed system, it is up to that system to fix the 

They selected the poor frequency.

In northern Ohio on the lakeshore cable operator near me was 
smart enough to NOT use amateur frequencies and not use 
marine frequencies. Because they were smart enough to avoid 
channels that would eventually always cause a problem, there 
never was a problem. That's the difference between smart 
cable technical management and dumb cable management.

73 Tom 

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