Is the center conductor of the el-cheapo RG-6 found in home
improvement stores always copperweld? It seems to be 18AWG copperweld
but maybe I'm being naive...

Is this part of the RG-6 mil-spec, or just the way they make it today?

Tim KA0BTD

the only way to tell is to take a sample and strip it down. some rg-6 is
copper covered steel, some is solid copper.

"Tim Shoppa" wrote in message
ups.com...
Is the center conductor of the el-cheapo RG-6 found in home
improvement stores always copperweld? It seems to be 18AWG copperweld
but maybe I'm being naive...

Is this part of the RG-6 mil-spec, or just the way they make it today?

Tim KA0BTD

Tim Shoppa wrote:

Is the center conductor of the el-cheapo RG-6 found in home
improvement stores always copperweld? It seems to be 18AWG copperweld
but maybe I'm being naive...

Is this part of the RG-6 mil-spec, or just the way they make it today?

Tim KA0BTD


The RG (Radio Guide) specs are mo longer used by military. Yes,
aluminum shielded RG 6 and RG-59 both used copperweld center conductors
for two reasons. the aluminum shield is weak, and tears if the wire
stretches. It also helps to limit the bending radius. I used to have
some "RG-6 headend cable" which had a double copper braid, and a silver
plated, solid copper center conductor. It was barely usable on US Ch 12
at 218 MHZ, but its claim only to fame was it had lower radiation or
signal ingression problems than the standard all copper, single braid
version.

--
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

Easy enough to find out- Take a magnet with you!
Years ago, had to deal with wire thieves, and they
could have saved US all, a lot of trouble, IF they
had done that! They even stole "Duplex" wire,
copperweld, that wouldn't even burn the insulation
off-- and was WORTHLESS (unless you needed a #14
power cord, 500 hundred feet long)! MOST Telephone
carriers, didnt even like that stuff (and they
topped out at around 40 KHz!! Jim NN7K



Tim Shoppa wrote:
Is the center conductor of the el-cheapo RG-6 found in home
improvement stores always copperweld? It seems to be 18AWG copperweld
but maybe I'm being naive...

Is this part of the RG-6 mil-spec, or just the way they make it today?

Tim KA0BTD

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

Roy Lewallen wrote:
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.

skin depth in copper at 1 MHz is about 2.6 mils( thousandths of an
inch). At 10 MHz, 0.8 mils (goes as the square root of frequency)

AWG18 is about 40 mils in diameter. If the copper thickness were, say,
3 or 4 skin depths.. call it 4-10 mils, almost all the current is
carried in copper.

Copper clad steel is usually specified as a percentage of conductivity
of pure copper (in AC powerline applications, for instance) as say, 40%.
If we make the assumption that steel is an insulator, 40% CCS would
have 40% of the cross sectional area.. that would mean the cladding is
about 11% of the overall diameter.
Using AWG18 as an example, 11% of 40 mils is about 4 mils, so certainly
at higher HF frequencies, 40% CCS would be pretty close to pure copper.
even 20% CCS (which would have cladding about half the thickness of 40%)
wouldn't be all that lossy.

At the VHF and higher frequencies typically used for 75 ohm coax, a very
thin cladding would be as good as solid copper.

(I note that there is coax with silver plated stainless steel as the
center conductor and shield for microwaves in cryogenic applications)


(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.

Always a wise idea, of course...


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

"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

"Tim Shoppa" wrote in message
ups.com...
Is the center conductor of the el-cheapo RG-6 found in home
improvement stores always copperweld? It seems to be 18AWG copperweld
but maybe I'm being naive...

Is this part of the RG-6 mil-spec, or just the way they make it today?

Tim KA0BTD

I did the refrigerator magnet test on several pieces of RG6, and the only
one that appears to be copperweld, for sure, was marked as 2300 MHz Digital
Satellite Cable. It is on my UHF TV antenna, and I think sold as RCA brand.

Tam/WB2TT