Author Topic: Philips PM5786B 125MHz pulse generator teardown  (Read 927 times)

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Offline picburnerTopic starter

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Philips PM5786B 125MHz pulse generator teardown
« on: August 13, 2021, 02:59:25 pm »
I bought this Philips pulse generator and, since I have to do some maintenance, I take the opportunity to take some shots during the teardown.
The PM5786B (1Hz-125MHz 2nS-0.1S risetime) is a completely manual instrument, it doesn't include any remote control.
The only maintenance works concern the replacement of a potentiometer with the broken shaft and the replacement of some electrolytic capacitors which have decreased their capacity and increased their internal resistance due to age.

The first pic shows the front view of the instrument.
The second pic shows the internal top view of the instrument.
The third pic shows the power supply board (Unit 1), below is the transformer protected by its shield.
« Last Edit: August 13, 2021, 03:24:13 pm by picburner »
 

Offline picburnerTopic starter

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Re: Philips PM5786B 125MHz pulse generator
« Reply #1 on: August 13, 2021, 03:01:47 pm »
Fourth and fifth pics: Transition time board (Unit 3).

Sixth and seventh pics: Timing board (Unit 2).
« Last Edit: August 13, 2021, 03:08:31 pm by picburner »
 
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Offline picburnerTopic starter

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Re: Philips PM5786B 125MHz pulse generator
« Reply #2 on: August 13, 2021, 03:03:46 pm »
Eight and ninth pics: Burst control board (Unit 7).

Tenth and eleventh pics: Front panel frame and board (Unit 6).

Twelfth and thirteenth pics: Output amplifier board, Unit 4 & Attenuator board (Unit 5).
« Last Edit: August 13, 2021, 03:19:33 pm by picburner »
 

Offline Scratch.HTF

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Re: Philips PM5786B 125MHz pulse generator teardown
« Reply #3 on: August 16, 2021, 12:31:51 am »
According to the service manual, the only custom IC in this unit is an analog multiplier and the ICs with a "100" prefix in the photos are off the shelf 100K ECL parts.
If it runs on Linux, there is some hackability in it.
 

Offline picburnerTopic starter

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Re: Philips PM5786B 125MHz pulse generator teardown
« Reply #4 on: August 16, 2021, 05:38:00 am »
Quote
According to the service manual, the only custom IC in this unit is an analog multiplier

Sharp observation. The IC in question is IC309 signed OQ0012 (I hope it lasts a long time ::)).
You can see it in the fourth pic on the right about in the middle.
« Last Edit: August 16, 2021, 01:42:47 pm by picburner »
 


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