CH3-34 100MHz frequency counter 70's

[strawberry]

Repair in progress. Module Nr11 one off decade dividers flip-flop Nr3 is faulty.   

What fancy can be done with frequency counter? What experiments can be done? Some plans to use u-blox 7 to obtain reference

[Inside21]

up to 120 MHz 
you may develop nice dizel-punk clocks

[ataradov]

Yeah, for 120 MHz counter it takes up a lot of space. It is also not from the 70s. The design is from early 80s with most units made in mid-80s.

There was optional prescaler module that would bring it up to 3 GHz or something like this.

It is a nice toy if you have space to store it, but the most practical value of this unit is in the precious metals it has inside.

[strawberry]

weight is to offset earth gravity effect on quartz stability ~10-8

wonder why they choose discrete TTL 500kHz ceramic hybrid, if available integrated circuits (CDIP)

not much precious metals, only for army or top precision

[TimFox]

Interesting:  I've never seen "chicken-head" knobs with a central screw before.

[strawberry]

~ 525 germanium transistors
neon displays are driven with 70V transistors

cant find quality schematics?

[Inside21]

service manual for this i can search on my work
but scan it only after 1 month. (extremly many working)

[khach]

cant find quality schematics?

http://www.xn--80alh0b.xn--p1ai/DOWNLOAD/CH3-34.ZIP
cyriilic url is strange but it work.

[Njk]

I'm not sure a frequency counter is a device designed for fancy experiments. Well, this thing is big. But if the requirement is to measure something that is within its spec, the good chance is that it will quickly become apparent that it's more convenient to do so with the old professional equipment than using a modern home entertainment device in shiny plastic box.

Also, no matter what the internal padding is, the enclosure itself is a thing of high value. It'll be a major enterprise for an individual to design it, to prepare all the materials, to find a casting service, a machining service, a painting service, etc., to manufacture something of that quality from scratch. And it will not be cheap anyway. A good pre-built GP housings of that class are also not cheap. This is a real metal thing that is closer to build-once-use-for-life model than modern tech toys, which becomes obsolete tomorrow, so it'll make sense to re-purpose the cabinet for whatever you want.

Thanks for reading. I admit I also could not find a standard quality wiring diagram. The best of my findings:

http://rcl-radio.ru/wp-content/uploads/2017/03/h3_34.pdf (UM and theory of operation)
http://electro-tech.narod.ru/schematics/measure/freq/ch3-34/ch3-34.djvu (schematics)

[GigaJoe]

on left - " 1987 "  ;  guess design around early 70-x,
does it have F-ref output ?   or input ?

[Njk]

F input, based on the spec. 1 or 5 MHz

[strawberry]

internal base f=5MHz and built in sub div output 100.. 10.. 1MHz 100.. 10.. 1kHz  and separate 10MHz ref output and 9digit BCD readout output

found built in tunnel diode 200MHz divider

seems that micro modules contain silicon semiconductors and germanium is only actual discrete packages

it got built in memory that store reading (live count can be switched on/off) only 6digits contain memory for some reason

function diagram could have been better(near impossible to understand)

HP5245L ?

[Wallace Gasiewicz]

The Nixie tubes are really cool, anything with Nixies is quite collectable although not as usable as more modern units.

I sold an American unit  (HP I think) unit like yours because an old friend REALLY wanted it.
As I recall in my unit the drivers for the Nixies were very hard to find, I did repair it and wish I would have kept it, gives a great "mad scientist" aura to the room.