In a message dated 12/20/01 7:43:38 PM Eastern Standard Time, w8ji@akorn.net
writes:
>
> > Why then difference in attenuation with higher frequencies for
> > different dielectric? Are you saying that there are no dielectric
> > losses in the coax?
>
> I hate to repeat stuff....so I won't. Read my post again.
>
I read it again:
<<To top this all off, there is virtually no difference in performance
using a foam dielectric. The vast majority of loss is conductor
resistance related, and has nothing to do with what dielectric is
used in a coaxial cable except as that dielectric affects the size of
conductor you can use for a given outside diameter to have a given
impedance.
If you use a closed cell foamed dielectric with large air cells it
allows the same conductors to be used, and loss is the same
without the headaches. The main reason that cable has low loss is
the center conductor is smooth and solid, and the shield area
carrying current is a smooth foil.>>
W1JR measured:
<<
RG213: 1.1
RG214: 1.15
Belden 9913: 0.84
LMR400: 0.7
1/2" Alumifoam: 0.3
>>
As far as I know, they are all just about the same diameters and wires used
in those cables, the difference is dielectric between the center conductor
and shield. I am having problem with your statement: "The vast majority of
loss is conductor resistance related, and has nothing to do with what
dielectric is
used in a coaxial cable..." Like, air "insulated" twin lead has the same
attenuation as plastic twin lead? (same wire)
> > Based on what? Modeling programs or real life comparisons?
> > My real life experience showed that Rhombic heard and worked stuff
> > that "yagiers" had no trace of. (Yea, anecdotal proof) Those who used
> > both know.
>
> When did you have Rhombics?
> What type yagis did you have and to compare them with?
> How many days did you A-B test the antennas?
> What was the test protocol you used?
>
Here we go again, why don't you answer the (same) questions and back up your
statements?
I asked the question and related to my experience as well as others who did
the same.
> Or is this like your the famous Razor beams that graced the cover
> of Radiosporting magazine and their alleged 10dB gain over 5
> element yagis???
Didn't you say to save the personal attacks for the bar fights?
You got your facts scrambled (again), it was on CQ magazines cover and Razors
got me many World records in CQ contests, which made me happy and I don't
care what is your "opinion" of them. There will be some going up at new N2EE
QTH and you will have the chance to observe their performance and run your
"test protocols".
Yuri, K3BU
AN Wireless Self Supporting Towers are now available! Windloading tables,
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