[Antennas] coax coax coax

[Chris Boone]

Actually, most of the time you can ignore the length and just cut to
whatever is needed...back 20+years ago, I ran tests on UHF with 3/4in CATV
hardline..made PL259s mate to it using brass compression fittings (3/4 to
1/2 in)...
Loss factored to be about 3db/100ft on 450MHz..SWR only increases loss over
1:1 about 0.5db or so/100ft AND 75 ohm cable has lower loss than 50ohm cable
to begin with! At VHF and HF, you dont even notice the SWR..and your losses
are less overall than equiv length of 50ohm line. As for antenna itself, all
you need to do it watch the velocity factor which is different than say 9913
or 1/2in Heliax...(and I dont recall it right now)...1000ft??? Enjoy the RF!
;)

Chris
WB5ITT


> -----Original Message-----
> From: antennas-bounces at mailman.qth.net 
> [mailto:antennas-bounces at mailman.qth.net] On Behalf Of Joe
> Sent: Monday, January 07, 2008 10:31 AM
> To: WB6BLV Central California
> Cc: Antennas at mailman.qth.net
> Subject: Re: [Antennas] coax coax coax
> 
> You can use this stuff for almost anything amateur related,  
> you just need to pay attention to cable lengths and cut accordingly.
> 
> 50 ohms in one end of a feedline that is electrically 
> multiples of 1/2 wavelength,  ends up repeating the same at 
> the other end  50 ohms.  it repeats regardless of the cables 
> impedance.
> 
> Joe WB9SBD
> 
> WB6BLV Central California wrote:
> 
> >go rhombic!!!
> >
> >John
> >WB6BLV
> >
> >
> >
> >
> >
> >  
> >
> >>I have about 1000' of 75 ohm cable company coax. Looks like a good 
> >>project
> >>    
> >>
> >for
> >  
> >
> >>some sort of antenna using the coax for the radiator. This 
> coax also 
> >>has
> >>    
> >>
> >the
> >  
> >
> >>steel support wire running the length.
> >>    
> >>
> >
> >  
> >
> >>Anyone ever used this stuff for some sort of bazooka type antenna?
> >>    
> >>
> >
> >  
> >
> >>Suggestions / comments.. I've got plenty of room for one BIG antenna
> >>    
> >>
> >project..