[Elecraft] TVI and More

[Fred Jensen]

See interspersed...

On 9/22/2021 5:24 PM, Richard wrote:
> A close neighbor was hearing through her add-on computer speakers what was probably me on 20 meter SSB. She said she couldn't make out any words, but it sounded like a garbled voice. After determining that it was indeed I she was hearing, I clamped a few ferrites on the two cheap speaker cables and the problem was solved. I hadn't had any interference problems since 1955!
You're just overloading the speakers.  If the ferrites worked, consider 
yourself very lucky and go buy a lottery ticket. 😉
> I think I read here on this reflector that there is some sort of filter that I can add to my transmission coax that will prevent this sort of thing. Can anyone tell me about this approach to TVI?
Only if you're living in the 1950's-1960's.  It's a low pass filter, 
they cut off just above 30 MHz, and its not usually an issue with 
today's radios and the fact that a great number of folks get their TV 
via satellite/cable/I'net.  In the olden days, transmitters had Class C 
power amplifiers, and harmonics were rampant and snuck into everything.  
Not so today.
> Oh, and my neighbor, who has an Alexa thing in every room in her house, all ganged together with WiFi, also said her Alexa was shutting off suddenly, then coming back on several seconds later. Could this Alexa-I? I wouldn't even know where to start on that one, especially since she has all that WiFi raging all through her house.
The clamp ferrites -->might<-- work on the power cables to the Alexa's, 
probably worth a try.  It's all just overload from your signal enhanced 
by the fact that nothing consumer-ish is shielded these days, and the 
ground lead in the cables goes to the circuit board and not the metal 
enclosure ... if there is one.  K9YC refers to it as the Pin One 
problem, and it is ubiquitous.


73,

Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County
>
> All help will be gratefully received.
>
> Richard
> W4KBX
>