HP 54121 part wanted

[Ian]

I'm after a TDR step generator for the HP 54121A test set (the front
end of the 54120 oscilloscope). The HP part number is 5086-7471.

 

[Kevin Carney]

They were available from Agilent about 2 years ago on an exchange bassis.
The part number for the exchange (they need the bad unit back) was 5086-6471
and cost around $ 800 US. Usually when the TDR got wacked so did the
sampler that follows the TDR block, sampler costs about $ 500 and is
exchanged too. Static damage in the dry winter climate was a common
problem. We used to put big Static warnings labels on the 54121 cover. I've
changed hundreds (samplers & tdr's) since 1987. We recommended people not
to use Channel 1 unless they were doing TDR work because they would damage
both TDR & sampler blocks. Channels 2,3 & 4 don't have TDR's, as you know.
Good Luck.......

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***************************************************
"We ought always to know precisely why a given job
is done in a particular way, and why it is done at
all, and why it can't be done more efficiently,
if it must be done at all."-- T.J.Watson

***************************************************

"Ian" <woodhead@lincoln.ac.nz> wrote in message
news:e156f876.0401291441.6c414dba@posting.google.com...

I'm after a TDR step generator for the HP 54121A test set (the front
end of the 54120 oscilloscope). The HP part number is 5086-7471.

 

[Ian]

Thanks Kevin. The sampler is ok 'cause I'd already repaired the TDR
(we do that down here where we're far from civilisation !!) - a
Schottky diode gate/bias network inside was zapped but new ones glued
in using a microscope and silver paint got it going again. Trouble is
the step is now a bit slower (80 odd ps vs < 50) and a bit more lumpy.
Now that I have more critical work to do, I again want the good spec,
but I guess Agilent will not want the doctored unit so I either
purchase new, get one from a trashed scope, or use an external step
generator ??

"Kevin Carney" <carneyke@us.ibm.combo> wrote in message news:<bve502$i5u$1@news.btv.ibm.com>...

They were available from Agilent about 2 years ago on an exchange bassis.
The part number for the exchange (they need the bad unit back) was 5086-6471
and cost around $ 800 US. Usually when the TDR got wacked so did the
sampler that follows the TDR block, sampler costs about $ 500 and is
exchanged too. Static damage in the dry winter climate was a common
problem. We used to put big Static warnings labels on the 54121 cover. I've
changed hundreds (samplers & tdr's) since 1987. We recommended people not
to use Channel 1 unless they were doing TDR work because they would damage
both TDR & sampler blocks. Channels 2,3 & 4 don't have TDR's, as you know.
Good Luck.......

--
change .combo to .com for correct email

***************************************************
"We ought always to know precisely why a given job
is done in a particular way, and why it is done at
all, and why it can't be done more efficiently,
if it must be done at all."-- T.J.Watson

***************************************************

"Ian" <woodhead@lincoln.ac.nz> wrote in message
news:e156f876.0401291441.6c414dba@posting.google.com...
I'm after a TDR step generator for the HP 54121A test set (the front
end of the 54120 oscilloscope). The HP part number is 5086-7471.

 

[Kevin Carney]

Wow, what finese in repairing the TDR ! I don't know what to tell you.
Maybe pick up a 54121 test set and use it for parts and hoping the TDR is
good.

--
change .combo to .com for correct email

***************************************************
"We ought always to know precisely why a given job
is done in a particular way, and why it is done at
all, and why it can't be done more efficiently,
if it must be done at all."-- T.J.Watson

***************************************************

"Ian" <woodhead@lincoln.ac.nz> wrote in message
news:e156f876.0402101915.275c8431@posting.google.com...

Thanks Kevin. The sampler is ok 'cause I'd already repaired the TDR
(we do that down here where we're far from civilisation !!) - a
Schottky diode gate/bias network inside was zapped but new ones glued
in using a microscope and silver paint got it going again. Trouble is
the step is now a bit slower (80 odd ps vs < 50) and a bit more lumpy.
Now that I have more critical work to do, I again want the good spec,
but I guess Agilent will not want the doctored unit so I either
purchase new, get one from a trashed scope, or use an external step
generator ??

"Kevin Carney" <carneyke@us.ibm.combo> wrote in message
news:<bve502$i5u$1@news.btv.ibm.com>...
They were available from Agilent about 2 years ago on an exchange
bassis.
The part number for the exchange (they need the bad unit back) was
5086-6471
and cost around $ 800 US. Usually when the TDR got wacked so did the
sampler that follows the TDR block, sampler costs about $ 500 and is
exchanged too. Static damage in the dry winter climate was a common
problem. We used to put big Static warnings labels on the 54121 cover.
I've
changed hundreds (samplers & tdr's) since 1987. We recommended people
not
to use Channel 1 unless they were doing TDR work because they would
damage
both TDR & sampler blocks. Channels 2,3 & 4 don't have TDR's, as you
know.
Good Luck.......

--
change .combo to .com for correct email

***************************************************
"We ought always to know precisely why a given job
is done in a particular way, and why it is done at
all, and why it can't be done more efficiently,
if it must be done at all."-- T.J.Watson

***************************************************

"Ian" <woodhead@lincoln.ac.nz> wrote in message
news:e156f876.0401291441.6c414dba@posting.google.com...
I'm after a TDR step generator for the HP 54121A test set (the front
end of the 54120 oscilloscope). The HP part number is 5086-7471.