In message
,
BillyBobMarley writes
On Jul 3, 11:54*am, walt wrote:
On Jul 3, 10:11*am, "Ralph Mowery" wrote:



"Ian Jackson" wrote in message

...

But, when the coax is stretched, what happens to the characteristic
impedance and the loss? [This is a (sort of) serious question!]
--
Ian

If the ratio of the conductors stay the same, there should not be a change
except the losses go up. *As you streach the coax, the shield and
the center
conductor will get smaller. *Also the dialectric will have to get smaller.
If they do not srink at the same ratio, the impedance will change depending
on which conductor gets smaller the fastest.

The losses will go up because the center conductor and the outer conductor
are smaller. *This is the simple IR loss of the conductors. *It is the same
as going from a rg-8 to a rg-58 type coax.

I'd be pleased to trade two buckets of prop wash for a coax stretcher.
Any takers?

Walt, W2DU

I see your prop wash and will give you a left handed pipe wrench in
exchange.If not the pipe wrench how about a can of muzzle blast?

I suppose a long screw is out of the question?
--
Ian

Ralph Mowery wrote:
Is there a shortage in the supply of coax ? A ham up the road has been
trying to get some rg8x from The Wireman for a couple of weeks. They are
out and said they should have some in soon.

There was a long discussion here about using compression type F connectors
(and BNC) with RG/6QS coax recently. I suggest that you look it up and refer
your friend to it.

The general consesus was that RG6QS was a pretty good choice for amateur
use. Not the best, but for the usual low power setup, it was ok.

There is RG6QS coax designed for satellite downleads (1-2gHz) so if you
get that it should work for 900 and 1296mHz, possibly 2.4gHz.

It is very important to note that we were talking about COMPRESSION
connectors, which compress from front to back sealing the cable in,
and NOT crimp on connectors, which are squeezed from side to side and often
fall off.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
I do multitasking. If that bothers you, file a complaint and I will start
ignoring it immediately.

In message , Geoffrey S.
Mendelson writes
Ralph Mowery wrote:
Is there a shortage in the supply of coax ? A ham up the road has been
trying to get some rg8x from The Wireman for a couple of weeks. They are
out and said they should have some in soon.

There was a long discussion here about using compression type F connectors
(and BNC) with RG/6QS coax recently. I suggest that you look it up and refer
your friend to it.

The general consesus was that RG6QS was a pretty good choice for amateur
use. Not the best, but for the usual low power setup, it was ok.

There is RG6QS coax designed for satellite downleads (1-2gHz) so if you
get that it should work for 900 and 1296mHz, possibly 2.4gHz.

It is very important to note that we were talking about COMPRESSION
connectors, which compress from front to back sealing the cable in,

Usually known on the business as 'Snap and Seal' (or 'Snap-N-Seal',
'SNS' etc) connectors. This type is now the only type used in most of
the UK cable TV industry (and, no doubt, in the USA). They are very
difficult to pull off, and are essentially watertight.

For example:
http://www.wittenberg-antennen.de/snapnseal.pdf
http://www.3starinc.com/lrc_sns11as_...le_f_connector.
html

You do, of course, need the appropriate tool.

and NOT crimp on connectors, which are squeezed from side to side and often
fall off.

'Proper' crimp connectors, properly crimped, with the 'proper' tool, are
also hard to pull off - at least, mine are!
--
Ian

Ian Jackson wrote:
You do, of course, need the appropriate tool.

They are relatively cheap. I've seen a set of tool, cutter and stripper
(3 tools) and 20 F connectors for as little as $12 on eBay. Here, a month
ago I paid $60 for such a set without connectors, today when I went to
the same store, the tool alone was $30. Last month they did not have the
tool alone.

The bad news is that they raised the price on the connectors from $.90 each
to $1.25 each, but dropped them to $.77 if you bought 100. They had 2 packages
of 50 and to convince me not clean them out, they gave me the 100 price
for 50.


and NOT crimp on connectors, which are squeezed from side to side and often
fall off.

'Proper' crimp connectors, properly crimped, with the 'proper' tool, are
also hard to pull off - at least, mine are!

From my experience, the tools are more expensive, and the skill level required
is much higher to get the done properly. Most of the crimp on ones are not
water resistant, while most of the compression ones are.

Geoff.
--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
I do multitasking. If that bothers you, file a complaint and I will start
ignoring it immediately.

"Geoffrey S. Mendelson" wrote in message
...
Ralph Mowery wrote:
Is there a shortage in the supply of coax ? A ham up the road has been
trying to get some rg8x from The Wireman for a couple of weeks. They are
out and said they should have some in soon.

There was a long discussion here about using compression type F connectors
(and BNC) with RG/6QS coax recently. I suggest that you look it up and
refer
your friend to it.

The general consesus was that RG6QS was a pretty good choice for amateur
use. Not the best, but for the usual low power setup, it was ok.

There is RG6QS coax designed for satellite downleads (1-2gHz) so if you
get that it should work for 900 and 1296mHz, possibly 2.4gHz.

It is very important to note that we were talking about COMPRESSION
connectors, which compress from front to back sealing the cable in,
and NOT crimp on connectors, which are squeezed from side to side and
often
fall off.

Geoff.

Thanks for the reply. My friend has been a ham for over 40 years and was
an electronic engineer involving RF. I have been a ham close to 40 years
and also know a bit about the types of coax. He just does not want to use
the rg-6 types. As we both have many ot the connectors for rg-8 and
adaptors for the 8x and 58 types it is no use to get the rg-6./ Also as
pointed out you often need special connectors or tools to install the F
connectors for outside use. He has a small setup of just two or 3 antennas
and does not want to buy special tools for the rg-6. I have often use over
1000 watts for the low bands and also work weak signals on 6 meters and
above. That leaves me out for the smaller coax also. Neither of us like
the solid small wires for outside use on 80 meter dipoles. Too much flexing
in the wind. I am not sure what the losses would be for the copper coated
steel often used in some of the rg-6 at frequencies below 10 mhz where he
wants to use it.

It just seems that some things seem to be in short supply at differant times
in this country. Around 1974 there was a gas shortage ( I think that was
when the shortages started), one year it was a toilet paper shortage, one
year it was a chicken shortage. For about the last year or two it was an
ammunition shortage for guns.

Every time it snows in the South US there is a big run on bread and milk and
that runs out .

We were just wondering if the one big supplier close by was the only one
having trouble getting coax.

I don't know much about the making of coax amd other wire, but assume it is
like where I work. We make polyester material that is shipped out for car
tires and other things. The machines are set up for one type of material
and ran for a while . When the warehouse is stocked with that, we change
the machines to run another type. If the inventory is running low on one
type, it may be a while before we switch over to run it again.

In message , Ralph
Mowery writes




We were just wondering if the one big supplier close by was the only one
having trouble getting coax.

Maybe the quantities of coax being manufactured these days is being
affected by the increasing demand for optical fibre?




--
Ian

"Ian Jackson" wrote in message
...
In message , Ralph Mowery
writes




We were just wondering if the one big supplier close by was the only one
having trouble getting coax.

Maybe the quantities of coax being manufactured these days is being
affected by the increasing demand for optical fibre?


Could be. While I would think it would take a differnat plant to make the
OF, maybe not as much coax is used and some plants have shut down making the
coax. Hard telling how many miles of coax was made for cable TV/internet
and computer connections that are now going to the OF.

Ian Jackson wrote:
In message
,
BillyBobMarley writes
On Jul 3, 11:54 am, walt wrote:
On Jul 3, 10:11 am, "Ralph Mowery" wrote:



"Ian Jackson" wrote in
message

...

But, when the coax is stretched, what happens to the characteristic
impedance and the loss? [This is a (sort of) serious question!]
--
Ian

If the ratio of the conductors stay the same, there should not be a
change
except the losses go up. As you streach the coax, the shield and
the center
conductor will get smaller. Also the dialectric will have to get
smaller.
If they do not srink at the same ratio, the impedance will change
depending
on which conductor gets smaller the fastest.

The losses will go up because the center conductor and the outer
conductor
are smaller. This is the simple IR loss of the conductors. It is
the same
as going from a rg-8 to a rg-58 type coax.

I'd be pleased to trade two buckets of prop wash for a coax stretcher.
Any takers?

Walt, W2DU

I see your prop wash and will give you a left handed pipe wrench in
exchange.If not the pipe wrench how about a can of muzzle blast?

I suppose a long screw is out of the question?


Must.....Resist..... Temptation....

On Fri, 2 Jul 2010 15:00:03 -0700 (PDT), Gary
wrote:

On Jul 2, 9:28*am, "Ralph Mowery" wrote:
Is there a shortage in the supply of coax ? *A ham up the road has been
trying to get some rg8x from The Wireman for a couple of weeks. *They are
out and said they should have some in soon.

There was also some mention of shortage of the open wire\twinlead type.

Is it just this place or is there some shortage in the US of coax and antena
wire.
What about the other coax such as the rg8 size ?

I ran in to the same thing last August at the Huntsville, Al. hamfest-
no 450 ohm open wire line. The high cost of copper prohibits them
from keeping too much inventory on hand. Apparently not much has
changed since August.

The cost of Copper(World wide) hit an all time high about a year ago,
(maybe a bit more) by, IIRC more than rippling, but then dropped
substantially, although not to the original level. It has been working
its way back up slowly.

Another commodity that has skyrocketed is wood. My neighbor did a
remodeling job this spring and saw the price of plywood take a
tremendous jump. Again, this is world wide, not a local or country
wide problem.

The economies of the two most populous countries are taking off at
fantastic rates. In the next decade India will have more college
graduates entering the middle class than the entire population of the
US. China has an almost unbelievable housing boom.

Don't expect things to get much cheaper.


73

Roger (K8RI)

Gary N4AST

On 07/08/2010 06:30 PM, Roger wrote:
On Fri, 2 Jul 2010 15:00:03 -0700 (PDT),
wrote:

On Jul 2, 9:28 am, "Ralph wrote:
Is there a shortage in the supply of coax ? A ham up the road has been
trying to get some rg8x from The Wireman for a couple of weeks. They are
out and said they should have some in soon.

There was also some mention of shortage of the open wire\twinlead type.

Is it just this place or is there some shortage in the US of coax and antena
wire.
What about the other coax such as the rg8 size ?

I ran in to the same thing last August at the Huntsville, Al. hamfest-
no 450 ohm open wire line. The high cost of copper prohibits them
from keeping too much inventory on hand. Apparently not much has
changed since August.

The cost of Copper(World wide) hit an all time high about a year ago,
(maybe a bit more) by, IIRC more than rippling, but then dropped
substantially, although not to the original level. It has been working
its way back up slowly.

Another commodity that has skyrocketed is wood. My neighbor did a
remodeling job this spring and saw the price of plywood take a
tremendous jump. Again, this is world wide, not a local or country
wide problem.


A lot of plywood comes from Chile and Brasil. Now, all of it is used in
new buildings after the earthquake in Chile and Haiti


The economies of the two most populous countries are taking off at
fantastic rates. In the next decade India will have more college
graduates entering the middle class than the entire population of the
US. China has an almost unbelievable housing boom.

Don't expect things to get much cheaper.


73

Roger (K8RI)

Gary N4AST

Alejandro Lieber
Rosario Argentina

--- news://freenews.netfront.net/ - complaints: ---