🚀 go-pugleaf

> Can someone tell me what causes a shadow or double image on a TV?
> 
> My config:
>                        Splitter(3.8db loss)
>                |\      
>  ANT >---------| >-----+-----> TV
>                |/      |_____> Stereo
> 
>              30dB WB(50M-1G) LNA
> 
> I inserted an amp just after the antenna just so I could see channel
> 68(FOX,~795M) better. The VHF signals were all about 10 mv, UHF
> 75-100uv.  The UHF jumped to about 200mv w/the amp, VHF 1-5mv.
> 

Shadows are caused by reflections; usually, reflections on the line ("lead-in")
due to an imedance mismatch. (They can also be caused by reflections of the
signal from, say, nearby buildings or even mountains, in which case you can
sometimes clear 'em up by re-aiming the antenna.)  

My guess is that something's wrong, impedance-wise, somewhere between the 
antenna and the amp.  Look for a kink in the line, broken wires, etc..  (It's
more likely to be here as this is - I assume - the longest run of line, and
hence the reflections have the farthest to travel, making for more distinct
"ghosts."  However, it *could* be after the amp, esp. if you've got a lengthy
run of cable between the amp and the TV or stereo.


Bob Myers  KC0EW   Hewlett-Packard Co.      |Opinions expressed here are not
                   User Interface Tech. Div.|those of my employer or any other
myers@fc.hp.com    Fort Collins, Colorado   |sentient life-form on this planet.