Author Topic: HP 5315A wont count  (Read 1195 times)

0 Members and 1 Guest are viewing this topic.

Offline Daxxin

  • Regular Contributor
  • *
  • Posts: 198
HP 5315A wont count
« on: April 25, 2017, 12:02:14 pm »
Power on test looks fine exit with all 3 zeros but from that status wont give any sign of life
even apply input channel signal.



following the signal 10Mhz from sine generator looks like comparator chip is faulty if someone can confirm



chip 1826-0426  AM68TADL (cannot find any datasheet ...equivalent?)
« Last Edit: April 25, 2017, 12:03:48 pm by Daxxin »
 

Online Dr. Frank

  • Super Contributor
  • ***
  • Posts: 1719
  • Country: de
Re: HP 5315A wont count
« Reply #1 on: April 25, 2017, 12:32:44 pm »
What about the trigger level on pin 8?

Is it possible to change this?

Maybe the voltage on this pin is way off, due to another defect, i.e. constantly @ +5V or -5.2V.

Are the supply pins 6, 11 correctly fed?
Are all supply voltages present? I see some tantalum caps, which also could have failed.

What about channel B, is it functional, instead?

Frank

« Last Edit: April 25, 2017, 12:45:10 pm by Dr. Frank »
 

Offline Daxxin

  • Regular Contributor
  • *
  • Posts: 198
Re: HP 5315A wont count
« Reply #2 on: April 25, 2017, 12:51:43 pm »
What about the trigger level on pin 8?

Is it possible to change this?

Maybe the voltage on this pin is way off, due to another defect, i.e. constantly @ +5V or -5.2V.

Are the supply pins 6, 11 correctly fed?
Are all supply voltages present? I see some tantalum caps, which also could have failed.

What about channel B, is it functional, instead?

Frank
feeds is correct , common button trigger/sensivity , in trigger mode turning the knob i get from -2.54v to +2.54v
in sensivity mode from -0.041v to +0.066v

expecting square waveform on comparator output ..im right?
 

Online Dr. Frank

  • Super Contributor
  • ***
  • Posts: 1719
  • Country: de
Re: HP 5315A wont count
« Reply #3 on: April 25, 2017, 01:22:19 pm »
Yes, I'd expect complementary square waves on both outputs (180°).
Anyhow, if you apply the signal to channel B, you should see either this correct output (square wave), or also noise, like on channel A.

This would indicate, if the whole IC is dead, or the upper OpAmp only.

As a replacement, you'll need a double fast comparator.
This one might be an ECL line driver, which might not be available anymore, as of today.

Frank
 

Offline Daxxin

  • Regular Contributor
  • *
  • Posts: 198
Re: HP 5315A wont count
« Reply #4 on: April 25, 2017, 01:26:03 pm »
Yes, I'd expect complementary square waves on both outputs (180°).
Anyhow, if you apply the signal to channel B, you should see either this correct output (square wave), or also noise, like on channel A.

This would indicate, if the whole IC is dead, or the upper OpAmp only.

As a replacement, you'll need a double fast comparator.
This one might be an ECL line driver, which might not be available anymore, as of today.

Frank

OK thanks for helping Dr.Frank both sides dead i m checking  MAX912 datasheet as replacement it looks very fine
« Last Edit: April 25, 2017, 01:28:37 pm by Daxxin »
 

Online Dr. Frank

  • Super Contributor
  • ***
  • Posts: 1719
  • Country: de
Re: HP 5315A wont count
« Reply #5 on: April 25, 2017, 02:00:33 pm »
This MAX912 has a TTL output, which will probably not work.

My guess was correct, see page 8-9, or 83/106 in the manual- the comparators have ECL outputs, which usually means negative output signals.

PS: maxim still offers ECL comparators, like the max9693.
I checked pinning, this type is more suitable, and it's also fast enough for > 100MHz.

Frank


« Last Edit: April 25, 2017, 02:05:19 pm by Dr. Frank »
 

Online lowimpedance

  • Super Contributor
  • ***
  • Posts: 1063
  • Country: au
  • Watts in an ohm?
Re: HP 5315A wont count
« Reply #6 on: April 26, 2017, 06:56:09 am »
chip 1826-0426  AM68TADL (cannot find any datasheet ...equivalent?)
The part number is AM687ADL   no T
datasheet here
http://www.datasheets360.com/part/detail/am687adl/961240802637534603/?alternatePartManufacturerId=0

And the MAX9693  that Dr. Frank found looks like an excellent replacement.
The odd multimeter or 2 or 3 or 4...or........can't remember !.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf