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Old April 8th 06, 10:15 PM posted to rec.radio.amateur.antenna
AK
 
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Default Velocity Factor (VP) for RG8X?

Is 78% the correct velocity factor for RG8X coax?


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Old April 8th 06, 10:17 PM posted to rec.radio.amateur.antenna
Dave
 
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Default Velocity Factor (VP) for RG8X?

that is what is listed in the belden catalog

"AK" wrote in message news:KRUZf.88176$oL.627@attbi_s71...
Is 78% the correct velocity factor for RG8X coax?



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Old April 8th 06, 10:20 PM posted to rec.radio.amateur.antenna
AK
 
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Default Velocity Factor (VP) for RG8X?

Thanks Dave. The only Belden catalog info I could find on-line didn't list
the VP. Is there a link for full Belden info you could give me? AK


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Old April 8th 06, 11:41 PM posted to rec.radio.amateur.antenna
Roy Lewallen
 
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Default Velocity Factor (VP) for RG8X?

My experience is that the velocity factor of foam dielectric cable like
RG8X varies considerably from batch to batch and manufacturer to
manufacturer. Apparently they have poor control over the foam density in
the manufacturing process. For any application where it really matters,
you really have to measure it for the particular piece of cable you'll
be using.

Roy Lewallen, W7EL

AK wrote:
Is 78% the correct velocity factor for RG8X coax?


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Old April 9th 06, 12:05 AM posted to rec.radio.amateur.antenna
Dave
 
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Default Velocity Factor (VP) for RG8X?

i have a paper catalog, don't know about on-line links for them.

"AK" wrote in message
news:eWUZf.88181$oL.84498@attbi_s71...
Thanks Dave. The only Belden catalog info I could find on-line didn't list
the VP. Is there a link for full Belden info you could give me? AK





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Old April 9th 06, 04:23 AM posted to rec.radio.amateur.antenna
Ed
 
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Default Velocity Factor (VP) for RG8X?

i have a paper catalog, don't know about on-line links for them.



All the info in your paper catalog is available online at belden.com
.. All the original poster has to do is click on " Catalog " , then the
" e-catalog " and then type in his cable type, ( RG8X) in the search
window. Belden will then display the one type of RG8X cable they make,
their number 9258. If one then clicks on this number, the complete
specs will be displayed. Just scroll down the specs and one will find
the velocity factor of Belden's RG8X is 82%.

http://bwccat.belden.com/ecat/jsp/In...1=undefined&P2
=undefined&P3=undefined&P4=undefined&P5=undefined& P6=undefined


Ed K7AAT
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Old April 9th 06, 06:33 AM posted to rec.radio.amateur.antenna
Reg Edwards
 
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Default Velocity Factor (VP) for RG8X?

My experience is that the velocity factor of foam dielectric cable
like
RG8X varies considerably from batch to batch and manufacturer to
manufacturer. Apparently they have poor control over the foam

density in
the manufacturing process. For any application where it really

matters,
you really have to measure it for the particular piece of cable

you'll
be using.

Roy Lewallen, W7EL

====================================

And the same applies to impedance Zo and attenuation.
----
Reg.


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Old April 9th 06, 06:46 AM posted to rec.radio.amateur.antenna
Cecil Moore
 
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Default Velocity Factor (VP) for RG8X?

Reg Edwards wrote:
And the same applies to impedance Zo and attenuation.


How much could the Z0 vary for "50 ohm" coax?
--
73, Cecil http://www.qsl.net/w5dxp
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Old April 9th 06, 11:31 AM posted to rec.radio.amateur.antenna
BKR
 
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Default Velocity Factor (VP) for RG8X?

Roy is right. You must meaure your cable to be sure.
The stuff I have now calculates to .73 using a regular MFJ analyzer.




Roy Lewallen wrote:
My experience is that the velocity factor of foam dielectric cable like
RG8X varies considerably from batch to batch and manufacturer to
manufacturer. Apparently they have poor control over the foam density in
the manufacturing process. For any application where it really matters,
you really have to measure it for the particular piece of cable you'll
be using.

Roy Lewallen, W7EL

AK wrote:

Is 78% the correct velocity factor for RG8X coax?

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Old April 9th 06, 12:01 PM posted to rec.radio.amateur.antenna
Reg Edwards
 
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Default Velocity Factor (VP) for RG8X?


"Cecil Moore" wrote in message
. com...
Reg Edwards wrote:
And the same applies to impedance Zo and attenuation.


How much could the Z0 vary for "50 ohm" coax?
--

=================================

For coax, Zo = 60 * VF * Ln( D / d )

So Zo varies as VF varies.

You'll just have to measure VF or Zo.

Similar for attenuation.
----
Reg.


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