SG-816/U High Power Pulse Generator

[graybeard]

I bought this pulse generator about 25 years ago at the W6TRW swap meet.  It has always worked, and was working the last time I fired it up about two years ago.  It is capable of putting a 50 Volt pulse into a 50 Ohm load, that is 50 Watts of power.

I have never been able to locate any documentation for this unit, so please chime in if you know of a source.  It was built by Systron-Donner/Datapulse in Culver City California in 1969, based on the component date codes.

It is an interesting hybrid circuit that uses Silicon bipolar transistors, Silicon and Germanium diodes, 2 nuvistors, and a pair of of 7534 high power/high reliability pentodes as cathode follower output drivers.

It is a somewhat unique instrument, so I thought I would share some photos.  You can click on any of the photos to see the full resolution images.





































































































... Chris

[0culus]

Very cool...for radar testing I presume? Guessing since it says made for the Navy.

[graybeard]

Very cool...for radar testing I presume? Guessing since it says made for the Navy.

When I did some more online searching for a manual I found two references to it being used for Sonar tests.

... Chris

[TimFox]

I looked at the datasheet you linked for the 7534 output tubes--quite impressive.  Before this, I was unaware of frame grids in power tubes, which gave the 7534 a 25 mA/V transconductance and very low screen current (4 mA).
Back in grad school, I used Delco high-voltage TO-3 transistors (higher voltage part in the same series as your DTS-423) to generate 1000 V pk-pk deflection waveforms, using a cascode totem-pole output stage.

[graybeard]

Running bipolars in common base mode (cascode output stage) allows you to swing the almost full base-collector breakdown voltage on the device so long as it is not in a high radiation environment.

[graybeard]

I fired it it up again today.  Here are some output waveforms into a 50 Ohm load.  I used a 20W 20db attenuator into a 2W 20dB attenuator into a 50 Ohm feed through termination.











Chris

[graybeard]

I was looking again online to see if I could find a manual for the SG-816/U High Power Pulse Generator.  I have not, but I did find specifications for it:








Chris