Note that partial air core (9913) and foam dielectric is better than
solid polyethylene.
David N1HAC
On 11/21/16 5:39 PM, Mark Spencer wrote:
At one point I contemplated running Andrews "Heliax" for my GPS antenna. Part
of the rationale was due to the data presented in page 2 of the follow
At one point I contemplated running Andrews "Heliax" for my GPS antenna. Part
of the rationale was due to the data presented in page 2 of the following paper.
http://ivs.nict.go.jp/mirror/meetings/v2c_wm1/phase_stability.pdf
I subsequently decided to stay with my existing run of plenum rated R
When I first took a look at some of the coax datasheets I couldn't find
anything. I was able to find the following paper "phase stability of
typical navy radio frequency coaxial cables"
http://www.dtic.mil/dtic/tr/fulltext/u2/628682.pdf I attached the table
from the last page. They estimate RG59 to
Several years ago I measured the delay of about 80 feet of LMR400
feeding a GPS antenna, much of which was lying on a black shingle roof
in the Georgia sun. I checked in early afternoon when the sun was
beating, and in the wee hours of the morning, to get the greatest
temperature delta. My re
On 11/21/16 6:38 AM, Scott Stobbe wrote:
If you had 30 ft of rg59 outdoors seeing maybe 10 degC swings everyday,
would the propagation time be stable to ps? ns?
Figure it's copper, so 16 ppm/deg C. velocity factor is about 2/3, so
30 ft is about 45 nanoseconds. about 1ps/degree
Really, you
In message
, Scott
Stobbe writes:
>If you had 30 ft of rg59 outdoors seeing maybe 10 degC swings everyday,
>would the propagation time be stable to ps? ns?
ps ?
No way - *ever*
ns ?
Probably, but it depends a lot on the exact materials and manufacturing.
--
Poul-Henning Kamp
If you had 30 ft of rg59 outdoors seeing maybe 10 degC swings everyday,
would the propagation time be stable to ps? ns?
On Sun, Nov 20, 2016 at 7:04 PM Hal Murray wrote:
>
> Is that even a sensible question? Is there a better way to phrase it?
>
>
> The problem I'm trying to avoid is that the w
