Al, thank you for your feedback. I stand corrected. But RFS did, in fact, spec
" annular" corrugated copper shield up until approx 2009. Now it is referred
to as "corrugated copper".
The point I intended to make to Bob is that it is
often referred to as "hard line" (to clarify his reference to HL) and that the
outer shield is corrugated. And, not as flexible as the Cellflex Tm name might
emulate.
Regards, Steve K1PEK, DAVIS RF Co., Snr. Cable Design Engr/Founder, DAVIS
RF Co.
________________________________
From: Al N6TA <al.n6ta@gmail.com>
Sent: Saturday, September 14, 2019 11:14 PM
To: Steve Davis | Davis RF <sdavis@davisrf.com>
Cc: towertalk@contesting.com <towertalk@contesting.com>; Robert Harmon
<k6uj@pacbell.net>
Subject: Re: [TowerTalk] Cell Flex Cable Question
A minor detail: Heliax does not use annular corrugation. A long time ago,
KabelMetal/RFS owned Phelps Dodge which came to be called Cablewave.
Cablewave needed to make a line of coax to compete with Heliax but it had to be
annular and not helical. They have been playing catch up ever since on coax as
well as elliptical waveguide. And parabolic dishes. Cablewave makes fine
product and is just as worthy as the bigger name brand. They make foam
dielectric and larger types of mainly air dielectric for those that need the
lowest of loss and have the money for it. They also do rigid coax that measure
in the inches with EIT connectors. I doubt the connectors are interchangeable
with those for Heliax.
Al
N6TA
On Sat, Sep 14, 2019 at 9:28 AM Steve Davis | Davis RF
<sdavis@davisrf.com<mailto:sdavis@davisrf.com>> wrote:
________________________________
Bob, 1/2" RFS Cellflex Tm is not as flexible as the name might imply. It is
not good for rotor loops unless you use a loop that is far longer than what
length you would use for say a LMR-400 UF or Belden 9913F7 (their Belden being
preferable for a number of reasons)
1/2" RFS Cable Wave Systems
Cellflex Tm IS, in fact, hardline. It uses an annularly corrugated outer
copper shield, same as Heliax.
At 20 M. the attenuation is low for many cable choices. Also, if you chose
Cellflex, you would want to use a rotor loop of 9913F7, etc. Splicing that in
with two connectors and a barrel adaptor, CONTRARY to popular belief, is going
to create such a low insertion loss, that there will never be any perceptible
negative factor to any receive or transmitted signal. I'm talking less than
.002 dB (at the MUF of the connector, 300 MHz is the MUF for our UHF
connectors) using our commercial connectors.
As I stated in the email to you this a.m, which crossed in the mail with your
posting here today, I will get back to you with facts, details, alternatives
and lower costs than 1/2" RFS
73 Steve K1PEK, Snr. Cable Design Engr/Founder, DAVIS RF Co.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com<mailto:TowerTalk@contesting.com>
> http://lists.contesting.com/mailman/listinfo/towertalk
------------------------------
Message: 8
Date: Sat, 14 Sep 2019 08:47:52 -0700
From: Robert Harmon <k6uj@pacbell.net<mailto:k6uj@pacbell.net>>
To: towertalk@contesting.com<mailto:towertalk@contesting.com>
Subject: [TowerTalk] Cell Flex cable question
Message-ID:
<5C2910DF-EAD9-4F29-8E2C-492CE3ADAD90@pacbell.net<5C2910DF-EAD9-4F29-8E2C-492CE3ADAD90@pacbell.net">mailto:5C2910DF-EAD9-4F29-8E2C-492CE3ADAD90@pacbell.net>>
Content-Type: text/plain; charset=us-ascii
Have you used Cell Flex cable from Davis RF ? Looking for feedback on this
cable. I am thinking
about replacing a 300 foot run of RG-213 from my shack to a 20M yagi with 1/2"
Cell Flex. . It looks like it would
give me approximately 1.8 db less loss for a 300 foot run if I figured it out
correctly. Much cheaper than hardline.
I am wondering if it is flexible enough to used in a rotator loop so I wouldn't
need to use a section of more flexible
cable for the loop ?
Bob
K6UJ
------------------------------
Subject: Digest Footer
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com<mailto:TowerTalk@contesting.com>
http://lists.contesting.com/mailman/listinfo/towertalk
------------------------------
End of TowerTalk Digest, Vol 201, Issue 41
******************************************
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com<mailto:TowerTalk@contesting.com>
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|