Hi Ken,
This is correct. Some other documents explain the rationale. Basically for long
runs the loss caused by the mismatch is less than the higher loss per foot of
50R coax of a similar size. Even better than RG59 is the high performance cable
used for cable TV and satellite installations.
kenkub...@hotmail.com said:
Hi Time-Nuts guys, I was reading the Trimble Thunderbolt manual section
2.1.3 (Antenna Cable). Trimble recommends using RG-59 cable which is 75 ohm
coax. Is this a typo or is this correct? I thought that the Trimble
Thunderbolt would use a 50 ohm cable and
Hi Ken,
Hi Time-Nuts guys, I was reading the Trimble Thunderbolt manual section
2.1.3 (Antenna Cable). Trimble recommends using RG-59 cable which is 75
ohm coax. Is this a typo or is this correct? I thought that the Trimble
Thunderbolt would use a 50 ohm cable and antenna.
Thankyou
Hi
Low noise receiver inputs are often mismatched to optimize noise figure.
Receiving antennas may / may not be well matched to a given impedance. That all
makes the mismatch loss a bit of a random thing. Some of the early Trimble docs
mention that they saw essentially no mismatch loss when
Its all been said above. Now I use zero loss ;-) 1/2 catv hardline 2 Ghz
stuff.
Regards
Paul
On Mon, Apr 30, 2012 at 7:33 AM, Bob Camp li...@rtty.us wrote:
Hi
Low noise receiver inputs are often mismatched to optimize noise figure.
Receiving antennas may / may not be well matched to a given
My TrueTime gps rcvr uses rg-59 as well.
Don
Robert Atkinson
Hi Ken,
This is correct. Some other documents explain the rationale. Basically
for long runs the loss caused by the mismatch is less than
the higher loss per foot of 50R coax of a similar size. Even better than
RG59 is the high
Yes, I use the regular satellite TV cable: low loss, easy to find and cheap.
On Mon, Apr 30, 2012 at 8:22 PM, Don Latham d...@montana.com wrote:
My TrueTime gps rcvr uses rg-59 as well.
Don
Robert Atkinson
Hi Ken,
This is correct. Some other documents explain the rationale. Basically
Make sure to buy the quadrouple shielded 75 Ohms RG-6 cable from Home Depot
etc, it's much better than the standard single or double shielded RG-6 and
works wonders for GPS signals, and it's quite inexpensive.
Impedance mismatch loss can be neglected, and long cable runs can be made.
bye,
Ken,
I believe that the manual also states that RG-59 has lower loss than RG-58,
but I would use RG-6 for even lower loss. Neither the antenna nor the
Thunderbolt cares much about the cable impedance.
73, Eric Lemmon WB6FLY
-Original Message-
From: time-nuts-boun...@febo.com
