[TenTec] Colliins SWR Bridge.....I'm also interested in EWR-PWR instrumentation.

[Dr. Gerald N. Johnson]

On Sun, 2009-12-13 at 07:04 -0500, al sirois wrote:
> 0700 EST
> 13 December 2009
> 
> Good morning, all:
> 
> I'm not overly impressed with the commonly accepted Bird meters in the ham
> community. I am looking for something much better, for sure. Guess I should
> look into this Collins Bridge 312B-4 or go to calibrated occiliscopes.
> 
> 73
> Al Sirois
> East Boothbay, ME
> N1mhc at arrl.net
> ==============
> 
How you do it with oscilloscopes, I'm not sure. I've heard that low
power Birds affect the impedance seen through them. That their coupling
is fairly tight and while they may show a matched load, driving through
them isn't matched, e.g. looking at the input of the last Bird with
another Bird. I've not tested that situation. Bird recommends adding a
length of coax to the Bird to make the assembly 1/2 wave long, so that
impedances aren't so much affected by the Bird.

Gerald J.