Owen with all due respect there is no "question" why 9914 has not replaced
Heliax and that is due to loss factors. BTW 9914 is impervious to water in
and of itself..so evidently you have not done much homework on this
particular coaxial cable. Davis 9914 is recommended for rotator loops. Your
supposed quandary about "9914 replacing Heliax" is contrived in my opinion
to murk up the waters of this issue and maybe steer focus away from what
obviously, at least to me, is an unfortunate one-time testing experience by
Roy.

Yes I suppose we should always be "suspicious" of manufacturer's claims but
do you exercise that philosophy across the board? How about the tires on
your car? How about the prescription medicines you may take and also over
the counter meds? How about those fast food burgers? How about your
drinking water? Are you as equally "suspicious" of these products or is this
philosophy of yours only revealed to others when you want to discredit
someone else's data. I think the later and not the former sir.

Owen....I give you a salute for being an obvious "spin doctor" for Roy's one
time, one sample, one conclusion, years ago test cycle.
A job well done on the surface..however the underlying facts remain. Davis
BuryFlex has been sold for well over 10 years in the "real world" and these
same real people, government agencies, municipalities, and service agencies
have used thousands of miles of it with no apparent issues. Cite similar
tests to Roy's and I'll reconsider.

As for me I'll go with the Davis data, once it arrives, and do a calibration
standards trace on their test station. Was Roy's test bench's
calibration traceable? It is preposterous you would continually cast
aspersions towards a company that has been in the wire and cable business
for over 25 years and promote and crusade for a one time shot-in-the-dark
independent so-called "test".

You do not fool me sir....best regards.....

-ps How many times do you think Davis has tested their 9914 in the past 10+
years?
More than the one single time Roy has perhaps?



--

Charlie


"Owen Duffy" wrote in message
...
On Sat, 10 Dec 2005 19:46:15 -0600, "Charlie"
wrote:

Owen it is NOT brand loyalty. It is the publicly published data by RF
Davis
(for the past 10+ years) vs. Roy's one-shot test setup some years ago.
I'm
not out to discredit Roy...I even shook his hand once at a Hamfest.

We should be a little suspicious of manufacturers claims. Davis' can
be expected to support their product.

Roy's single poor experience is concerning, indicating either a
quality control issue, or more general non-compliance with spec (both
are issues for Davis). An independent test of stock cable and possibly
Roy's sample would be most interesting.

I know I have made measurements and adjustments at times and in
searching for possible explanations, the cable quality is on the
radar. In one of those cases, a mobile installation could not be
trimmed properly, and the Taiwanese RG58 centre conductor was so far
off centre, it was nearly touching the braid.

We have all cut cables up and found inconsistent braid weave, open
braid weave, voids in the dielectric, faulty stranding of inner
conductor, off centre centre conductors. It is those kind of issues
that downgrade a suppliers reputation, not their ability to select a
good cable sample for laboratory measurement.

Perhaps if you're a whiz, you should perform some measurements so you
can report first hand your experience.

We don't see the Davis stuff on this side of the world. The concept
seems a good one, PE sheath, braid+foil outer, foam dielectric,
stranded inner, but you have to ask yourself why they haven't
displaced Heliax and its copies. I suspect the reasons include IM and
noise issues associated with the braid+foil, mechanical issues with
the foam, and resistance to water. Experience with noise and IM
problems with braid+foil coax in fixed installations makes me wonder
how it stands up in a rigorous test of flexing for a rotator loop, not
anecdotal evidence, but a structured test.

Owen
--