"Ken" wrote in message
...
On Fri, 26 Mar 2004 01:02:41 GMT, "Harold E. Johnson"
The 355's are a piece of cake. You can do it with DC and a voltmeter.


Hmmm. I tried it with an ohmmeter and didn't get what I expected.
Resistance increased to around 100 ohms and stayed there from around
60 dB up.
..... Ken KC2JDY

....does .."...on up" mean 60, 70, 80, 90. I don't remember the 355. Must
be a "D" ??

HOLD ON! Did you guys miss this part ? For a resistive attenuator, With
it set between 20dB and 60dB DC resistance will read very close to 50 ohms
from either center pin to ground. Then as the attenuation is reduced to its
minimum the resistance will climb. Both ends should read the same.


Figuring quickly (no pads or ohm meter handy) I may have this wrong, but in
true Usenet fashion will try anyway... Couldn't do it, so I cheated...

Using:
http://www.temcom.com/pages/dBCalc_en.html


Pad Rin (R1 + R3 Output open ckt)
1dB 436
3 150.5
6 83.6
10 61

355C Coaxial Step Attenuator Agilent 355
DC to 1 GHz, 0 to 12 dB in 1 dB steps, BNC connection standard.


355D Coaxial Step Attenuator Agilent 355
DC to 1 GHz, 120 dB in 10 dB steps, BNC connectors.