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Hi all:

i would be very very appreciated if you can tell me how to manage

these 2 ics.(acq board u501&u502,sn:tek 234 0718 40)

i got no 250Mhz signs from these 2 ics.

they are dead?

i approved the pic:



regards

--- In TekScopes@..., "clboy168" <clboy168@...> wrote:

Hi all:

i would be very very appreciated if you can tell me how to manage

these 2 ics.(acq board u501&u502,sn:tek 234 0718 40)

i got no 250Mhz signs from these 2 ics.

they are dead?

i approved the pic:



regards
-------------------------

I find it most unlikely that both these chips have died.
The outputs of these, as you marked, are 250 MHz ECL.
The inputs (ACQCLK) are also as you marked but are 250 MHz
on about +3VDC and not 1 GHz. These signals come from
U1001 pins 20 and 21. U502 also have DLYCLK from the same
source on pins 12 and 13. U1001 has its inputs (OSC500) on pins 40
and 41 which come from the VCO board (the small board monted
vertically) on pins 2 and 3. This should be about 500 mVpp, 500 MHz
on +3VDC.
/H?kan

Sir:
Thank you very much. How kind of you!
Yes,i made some mistakes.You are perfectly right.
Now,i have some new questions,
1: the ic(u502) got 250M(ACQCLK) input and DLYCLK input,but the output was not a 250M sign,just was a 10khz disturbing sign.Could
i say it's dead? u501 was the same.

2: how can i get the scope of the 250M(acqclk)?
i got a tek 520a to catch the sign,but failed.
So i used a frequency counter to catch the sign finally.

Regards

--- In TekScopes@..., "clboy168" <clboy168@...> wrote:

Sir:
Thank you very much. How kind of you!
Yes,i made some mistakes.You are perfectly right.
Now,i have some new questions,
1: the ic(u502) got 250M(ACQCLK) input and DLYCLK input,but the output was not a 250M sign,just was a 10khz disturbing sign.Could
i say it's dead? u501 was the same.

2: how can i get the scope of the 250M(acqclk)?
i got a tek 520a to catch the sign,but failed.
So i used a frequency counter to catch the sign finally.

Regards
------------

1: There are two more inputs that are common to both chips:
pin 9 (CLKMODE2) which should be TTL High
pin 24 (VSUB) which should be -10 VDC
2: With a TDS520A and a suitable probe you should be able to see
this signal.
/H?kan