TVI----Low pass filters!!!

[Billybob]

Hiya guys, Me again with my box of bits!

Anti TVI Filter and Low pass filters are they one of the same thing, or are they different gadgets altogether?

Ive had a Anti TVI filter knocking about here for a while but never used it. I was told not to bother with it unless needs must.

Now sorting through Ive came across a LOW PASS filter so I was wondering, if its not, whats it for????

Again any info on what it is for, or how it works would again be much appreciated

Billybob..*

[disgwylfa]

Yup - same animal

TV Filter - TVI Filter - Low Pass Filter - Anti TVI Filter
all different names for the same thing.

It's used to block harmonic emissions which might cause interference.

Typically a CB "TVI Filter" is a Low-pass filter that attenuates (blocks) any signal over about 30MHz, thereby letting the 'good' radio signal get through to the aerial, but blocking any stray high frequencies that might cause television interference.

A reasonable CB, on factory power, with a decent aerial and coax really shouldn't need a Filter. When you start pushing big wattage through (like a 100W+ burner and so forth) then the risk of TVI increases, or if there's a problem with the antenna, coax, plugs or CB.

If you read my own "Help" cry in the "Homebase CB Antenna" section, you'll see that sometimes even a Low-pass filter doesn't solve the problems.

[Billybob]

To the rescue again Steve!

I thought as much. Because I've seen these things in all sorts of shapes n sizes, prob to do with frecuency ranges and power handling capabilities n so on.


Like I mentioned in my other post in "Home base antennas" I've come across this box whitch has been given to me with all sorts of radio bits n pieces including this low pass box and matcher boxes etc... So if I come across anything else I'm not sure of, I'll bending the ears of the masses again, so dont go to far
I'm gonna take butchers at your "HELP" post now, cheers..

I've also found in that box a mouse trap and a rubber glove!

But I wouldnt know what board to post this issue on

Thanks again bud!
Billybob..*

[stampman]

probanly "fetishes 4 u " or " pain to go "

[Billybob]

Its probably a 'Jeramy Kile' waitng to happen!

I best leave it there for now!

Nice 1

Billy..*

[disgwylfa]

I've seen these things in all sorts of shapes n sizes, prob to do with frecuency ranges and power handling capabilities n so on.

Despite the shapes and sizes, most of the ones you'll see around CBs are very much the same, with the exception of their power handling capabilities.

The majority of the cheap filters have a top limit of about 25W, better ones go to 100W or 500W. Or, if you wanted a bit of confidence and high power, there are the 'Ham Quality' ones like the Kenwood LF-30A that'll handle a kilowatt . . . but they're about fifty quid.

There are Low-Pass filter for different frequencies in the world of Ham Radio, but there are more CBers with TVI than Hams, due [usually] to the quality of the kit and the level of knowledge of the users. It's rare to find a 'proper' Ham operator using a badly mismatched antenna and an overpowered, untuned transciever but surprisingly common to find a CBer doing the same - particularly in Muppet Land.

. . . pass box and matcher boxes etc...

I've also found in that box a mouse trap and a rubber glove

I'm sure Faceman, ' The Face', from the A-Team or MacGyver - equipped with a Swiss-Army knife, could build a planet-saving device form a mouse-trap, a low-pass filter, an antenna matcher and a rubber glove!

I'll go with Stampman's suggestion though, it's a topic for the "Pain and Fetish" forum.