Terminations vs Feedthrough Termination

[pmelci]

can we use an feedthrough termination (011-0049-01) instead of termination (HP 11593A) ?

there is a Tee Adaptor , one port is connected to Test Instrument , the other port terminated by 11593A termination.

Can i use only feedthrough termination to the input of TI or using Tee adaptor with feedthrough termination ?

Thanks. . .

[Bryan]

Should work OK with lower frequency stuff, higher frequencies would probably suffer effects from reflection since there is an open connector.  I've never tried to measure SWR on one.  I have seen it done measuring audio signals on DMM and seems OK.  What I wonder is why use a tee with a term on one leg instead of a feed-thru on the line in.

[mdbuike]

We calibrate our lab used ones here, but have found, depending on manufacturer and manufacture date, the VSWR drops out of specifications around 400 to 500 MHz..which is fine for most uses..we have also found VSWR is different at the male vs. female end of feedthroughs...
We use the MMS with the VSWR program (yes, it's DOS 4, but it still works..and I'm geek enough to keep it going)...

Mike

[pmelci]

It is in 8447F Amplifier T. O.  33K3-4-1204-1.
Equipment requirement list Termination is listed with N/A accuracy and bench equipment. In T. O.  only 100 KHz and 250 KHz are tested in mean . . . . . .  calibration.

I still wonder whether feedthrough termination is used or not instead of termination.

In terminations general calibration T. O.  (33K4-4-589-1), there is step 3. 6  which says :
"Feedthrough terminations must be calibrated as a non-terminated one-port devices. "

What does it mean ?

[mdbuike]

It means, in a 4 wire resistance configuration, you measure the male side with nothing on the female side, then you measure the female side with nothing on the male side...and one would hope that the differences are insignificant due to connector type

Just remember all the neat button pushes on the 3458A that make AFMETCAL inspectors happy

Mike