I found the Board PN listed under a Chinese website, for industrial products.
There was just a huge list of board part numbers only. Further info is proprietary.
Here is their testimonial translated in part below, using S3.translator in Firefox.
Well-known domestic listed companies Shuangliang energy-saving and environmental protection system known as China Co., Ltd. in the industry "Oscar" awards competitions in the titles and captured the industry the only win of the enterprise.
In the list of national award-winning business only 13 years, many of them Chinese Academy of Launch Vehicle Technology and other people carrying the pride and dreams of space science and technology enterprise, together with Shuangliang in the column, not a coincidence. Shuangliang was the first time the introduction of the civil aerospace engineering method of leak detection equipment manufacturing, to increase the vacuum bromine cooler to unprecedented heights, the whole crew leak rate a full four orders of magnitude lower than the Japanese Industrial Standard, beat from the performance to sophisticated known Japanese counterparts.
My guess is you got 1 good 1MHz channel already with high gain and low noise. Maybe even AGC.
- AD848 High Speed, Low Power 175MHz Monolithic Op Amp (1) Missing 1 in socket ??
- TL072 Low-Noise JFET-Input Dual (2) 3MHz Operational Amplifiers
- OL275 Dual Bipolar/JFET, 9MHz Audio Operational Amplifier (2 duals)
- AD8574 8-Bit Buffered Multiplying DAC 1MHz ? maybe (2)
For differential high speed Analog and digital channel, 1sensor
Differential mode PD? hmmm anyone?
Vintage US 1994 design with 8 digit part numbers from some large OEM with low noise TIA S/N 11 --- custom from elsewhere like Silicon Valley. I used to do stuff like this in the 80's 90's.
SIngle V+ in 24V with dual split supply for Analog and 5V ADC from ferrite DCDC reg. might be possible to hot power externally. Then observe analog outputs on TP turrets.
Or maybe you find out it is Scintillator product glass window contaminant counter or maybe Pigs will fly.