[Elecraft] OT - RG6 dual coax as feedline?

[Don Wilhelm]

Mike,

I know you have it in hand, but I would suggest using that cable as a 
parallel transmission line only for the lengths that must run indoors.  
Use normal ladder line or open wire transmission line for most of your 
transmission line run.

My reason:  The paralleled line certainly will work, but the loss is the 
same as a single coax of the same material, and in a multiband 
situation, it certainly will be run at a high SWR.  However, a shielded 
parallel line can be handled just like coax and run near surfaces where 
normal parallel line should not be located.  As such, it is a good 
solution for the shack entry cable.
Do tie the shields together and ground them at the entry point and in 
the shack.

You can use the remainder of it to feed resonant antennas.  If it is 
anything like normal RG-6 it will easily handle up to 500 watts even 
with a 1.5 SWR and will do it with less loss than RG-8X.  Because of the 
aluminum shield, use normal crimp type F connectors, or if you can 
locate them, there are BNC connectors for RG-6 coax with aluminum shield.

73,
Don W3FPR

Mike C wrote:
> Hello from K2 #4206 (Mike WB9GZL) with an OT
> question for the sat/cable/over-the-air-TV gurus. Springtime in Wisconsin for me involves trying new antennas
> for my K2. This past winter I was given a new
> 500-foot reel of RG6 dual coax w/messenger.
>
> Impedance:
> 75+/-3 Ohm
>
> 18 ga solid
> cu centers
>
> aluminum foil
> + 60% al braid
>
> My
> extensive searching has not uncovered any transmitting applications for this
> coax. Would you have an opinion if it could be used (with an appropriate balun
> at the TX, for example) as "twin-lead" feedline for balanced antennas such as an all-band doublet or
> perhaps an antenna with more variable characteristics such as a large loop?
>
> Thanks for
> any help you can provide, and for making this reflector an outstanding source
> of collective wisdom. Best regards from Mike WB9GZL.
>   
>