As per the VK1OD website chart RG-6 has less loss than anything else
shown. Matches RG-213 at 1.8 Mhz the place we are all looking at.
I can see where perhaps my twenty year old RG-6 could be improved
upon by using the quad shielded variety perhaps. Maybe more help on
receive than transmit by changing out the Coax over to the quad shielded
type.
Antenna system here is what you would call a K8UR version of a 4 square
array. Each feedline is 3/4 wavelength electrical length of plain Garden
Variety RG-6. It uses F connectors crimped at the Phasing Box end with
adapters to PL-259 to get into the box. The box and all is inside an
enclosure so weather isn't a consideration inside that box. The antenna end
of these feedlines is just pigtailed out with added copper wire to the shield
side. Connections to the antenna wires is done with Wire Nuts. I do put
NoAlox inside the wire nuts before they are screwed onto the connections.
I live in Northern Indiana in what is often referred to as "The Black Hole"
I hold the first all 40 zones on 160 award issued from the USA.
My present 160 meter dxcc total is 306.
I too would nearly kill for an additional 1/4 dB of receive ability or transmit
ability on 160.
It seems to me that RG-6 is pretty good coax for our purposes.
John k9uwa
> On 10/9/2011 3:33 PM, John K9UWA wrote:
> > can you tell me why one would NOT want to use the common variety of a
> > RG-6 that has a few strands of braid.. and foil + foam insulation and
> > the usual single wire center for an Antenna on 160 meters?
>
> 1) LOSS. Significant if it's a long run for flimsy shields. Also,
> copper clad steel is pretty lossy on the lower bands as compared to
> solid copper or copper clad Aluminum. If you're only going 25 ft, it
> doesn't matter.
>
> 2) SHIELDING If you've got much RF noise around you, you could benefit from
> a much more robust shield that what's on the cable you describe, especially on
> an RX antenna. Shielding is strongly dependent on the resistance of the
> shield, and foil shields aren't worth much until you hit VHF. BTW -- one
> thing that can be less than wonderful about those crimps is the resistance
> (and reliability) of the shield connection.
>
> 3) Define "almost nothing." :) I know guys (N6LF is one) who will go
> to extremes for less than half a dB when they're already maxed out on TX power
> and everything else in their system. I certainly agree that the loss in 25 ft
> of almost any coax on 160M doesn't matter.
>
> 73, Jim Brown K9YC
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
John Goller, K9UWA & Jean Goller, N9PXF
Antique Radio Restorations
k9uwa@arrl.net
Visit our Web Site at:
http://www.JohnJeanAntiqueRadio.com
4836 Ranch Road
Leo, IN 46765
USA
1-260-637-6426
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK
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