"Roy Lewallen" wrote in message
...
I'd be a little suspicious of el cheapo cable with copper plated steel
center conductor. I'd be surprised if it was Copperweld, which has a very
thick copper coating. Copper plating thickness would be a logical place
for cost-conscious vendors to skimp.

An extra thin layer of copper wouldn't hurt at VHF and above, but it could
really be a killer at HF, where significant current could flow in the
steel. (Steel is extra lossy at RF because its permeability further
reduces the skin depth by a large factor.) I'd definitely measure the loss
if I intended to use it at HF.

Of course, many (or most) amateurs would probably be pleased by the wide
bandwidth and low SWR and noise level they'd get with lossy cable.

Roy Lewallen, W7EL

Looking at a Belden listing for 5 different kinds of RG6, The loss at 10 MHz
is .9 DB/100' for the copperweld, and .7 DB for the solid copper. The db
loss at 1 MHz is about 1/2 the 10 MHz number. All have a loss of 7.3 DB at
1000 MHz, except the 9290 solid copper, which is 8.8 . I looked at less than
half of their different kinds of RG6, but a quick scan did not point out
anything odd.

Tam/WB2TT

Tam/WB2TT wrote:
"Roy Lewallen" wrote in message
...
I'd be a little suspicious of el cheapo cable with copper plated steel
center conductor. I'd be surprised if it was Copperweld, which has a very
thick copper coating. Copper plating thickness would be a logical place
for cost-conscious vendors to skimp.

An extra thin layer of copper wouldn't hurt at VHF and above, but it could
really be a killer at HF, where significant current could flow in the
steel. (Steel is extra lossy at RF because its permeability further
reduces the skin depth by a large factor.) I'd definitely measure the loss
if I intended to use it at HF.

Of course, many (or most) amateurs would probably be pleased by the wide
bandwidth and low SWR and noise level they'd get with lossy cable.

Roy Lewallen, W7EL

Looking at a Belden listing for 5 different kinds of RG6, The loss at 10 MHz
is .9 DB/100' for the copperweld, and .7 DB for the solid copper. The db
loss at 1 MHz is about 1/2 the 10 MHz number. All have a loss of 7.3 DB at
1000 MHz, except the 9290 solid copper, which is 8.8 . I looked at less than
half of their different kinds of RG6, but a quick scan did not point out
anything odd.

Tam/WB2TT

Belden isn't in the category of "el cheapo" cable, which was the subject
of my posting.

Roy Lewallen, W7EL

Roy Lewallen wrote:

Belden isn't in the category of "el cheapo" cable, which was the subject
of my posting.


Unless you collect thosands of feet of it from the local CATV dumpster
where they toss out partial boxes and reels. When I moved south I had
over a mile of it. It was all new scrap, and some pieces were over 300
feet.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida