On 12/26/2012 12:53 AM, Patrick Wong wrote:
Hi Doug,
I'm not sure how the OP's test would distinguish between
1) a situation where the attenuator resistor(s) is/(are) open and he
is introducing a load of 50 ohms with the passthrough terminator, vs.
2) a situation where the attenuator resistor(s) is/(are) fine, and the
passthrough terminator is used.
In both 1) and 2), the voltage measurement will probably drop by ~50%
when the passthrough terminator is introduced.
I like your other post offering an alternate way to test without
access to an antenna bridge. That alternative assumes the existence of
another RF generator whose output is loaded by the 608 attenuator.
Patrick Wong AK6C
--- In hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>, Doug <dmcgarrett@...>
wrote:
...If all you are doing is adding and removing a 50 ohm resistor
across the 608 output, and measuring the output with a scope, then
the test would seem to be kosher, IF you use a high-impedance 10:1
scope probe...
<;_ylc=X3oDMTJyZzkzdDl1BF9TAzk3MzU5NzE0BGdycElkAzEwOTI5MzMzBGdycHNwSWQDMTcwNTA4MzY2MwRtc2dJZAM0ODcyNQRzZWMDZnRyBHNsawNycGx5BHN0aW1lAzEzNTY1MDEyMTU-?act=reply&messageNum=48725>
The situation that Patrick envisions is somewhat unknown. I would guess
that if the attenuator resistors were blown, then adding
a 50 ohm load across the 608 output would probably cause the signal
level to drop MORE than 50%, but it would depend on what's
the actual impedance of the unterminated attenuator. So we may both be
wrong! I suggested the measurement with another
source of RF since the poster did not have an antenna analyzer, which of
course, is another source of RF. (The antenna analyzer
would have actually been my first attempt, because I do own one. But I
also own another RF generator or two-- a Measurements
Model 80 and two sweep generators that cover 10MHz.)
doug, WA2SAY
