[time-nuts] 75Z vs 50Z for GPS receivers

[Neon John]

On Sun, 28 Jan 2007 13:02:39 -0800, Brooke Clarke <brooke at pacific.net>
wrote:


>Long ago Bob Grove promoted the idea of using 75 Ohm TV coax for ham 
>antennas at 2 meters and higher frequencies because it had lower loss 
>than 50 Ohm coax and was much lower in cost.  For ham applications the 
>VSWR due to the coax impedance was much smaller than the inherent match 
>(mismatch) of the things on either end.

yes.  I started doing that in the late 70s when a large quantity of
CATV hard line fell into my possession.  I did some loss measurements
on a 500 ft roll and was pleasantly surprised to find the loss much
less than a roll of 1/2" 50 ohm hard line that I also had on hand.
>From then on I used CATV coax for all my ham activities on 2 meters
and above.  On 2 meters and 440 I was surprised to find the SWR
significantly lower than theory predicted, measured with a Bird
wattmeter.  I never had the time and curiosity at the same time to
investigate so I just tucked that one away in the long term storage
area of my brain.

John
---
John De Armond
See my website for my current email address
http://www.neon-john.com
Cleveland, Occupied TN
Don't let your schooling interfere with your education-Mark Twain