[RFI] Common mode choke on 4 Square feedlines without skewing phasing?

[john at kk9a.com]

I use RG302/U for 75 ohm chokes.

John KK9A


Jim Brown K9YC wrote:

Thanks Grant. In a quick search, I found RG179 on Pasternak's website,
but didn't see a relevant power rating at HF.  Looking at Belden's
datasheet, VF is 0.695, so a bit more shortening of the feedline will be
required as compared to LMR200-75.

73, Jim K9YC

On 1/23/2019 4:48 PM, Grant Saviers wrote:
> Another coax choice for 75 ohms is RG179, TFE + SCCS conductor +
> silver shield.  Slightly less diameter than RG400.  I've not had SCCS
> creep problems in dozens of QRO chokes I've made with 50 ohm SCCS
> RG142, but if buying new 50 ohm cable the stranded RG400 is the better
> choice. Belden says 1250 watts at 50MHz for the 75 ohm RG179, so for a
> 160m or 80m 4 sq probably has lots of headroom. 179 is available on ebay.