CH3-34 100MHz frequency counter 70's - Page 1
Forum section: electronics / testgear

author: strawberry
author_rank: Super Contributor
timestamp: April 26, 2023, 07:29:36 pm
content: 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

author: Inside21
author_rank: Contributor
timestamp: April 26, 2023, 08:09:19 pm
content: up to 120 MHzyou may develop nice dizel-punk clocks

author: ataradov
author_rank: Super Contributor
timestamp: April 26, 2023, 08:36:13 pm
content: 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.

author: strawberry
author_rank: Super Contributor
timestamp: April 26, 2023, 09:30:27 pm
content: weight is to offset earth gravity effect on quartz stability ~10-8wonder why they choose discrete TTL 500kHz ceramic hybrid, if available integrated circuits (CDIP)not much precious metals, only for army or top precision

author: TimFox
author_rank: Super Contributor
timestamp: April 26, 2023, 09:32:24 pm
content: Interesting: I've never seen "chicken-head" knobs with a central screw before.

author: strawberry
author_rank: Super Contributor
timestamp: April 27, 2023, 07:16:54 am
content: ~ 525 germanium transistorsneon displays are driven with 70V transistorscant find quality schematics?

author: Inside21
author_rank: Contributor
timestamp: May 06, 2023, 10:30:46 pm
content: service manual for this i can search on my workbut scan it only after 1 month. (extremly many working)

author: khach
author_rank: Contributor
timestamp: May 07, 2023, 06:14:05 pm
content: Quote from: strawberry on April 27, 2023, 07:16:54 amhttp://www.xn--80alh0b.xn--p1ai/DOWNLOAD/CH3-34.ZIPcyriilic url is strange but it work.

author: Njk
author_rank: Frequent Contributor
timestamp: May 07, 2023, 08:02:37 pm
content: 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)

author: GigaJoe
author_rank: Frequent Contributor
timestamp: May 08, 2023, 06:39:56 pm
content: on left - " 1987 " ; guess design around early 70-x,does it have F-ref output ? or input ?

author: Njk
author_rank: Frequent Contributor
timestamp: May 08, 2023, 07:09:48 pm
content: F input, based on the spec. 1 or 5 MHz

author: strawberry
author_rank: Super Contributor
timestamp: May 11, 2023, 07:31:56 pm
content: 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 outputfound built in tunnel diode 200MHz dividerseems that micro modules contain silicon semiconductors and germanium is only actual discrete packagesit got built in memory that store reading (live count can be switched on/off) only 6digits contain memory for some reasonfunction diagram could have been better(near impossible to understand)HP5245L ?

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: May 11, 2023, 11:53:39 pm
content: 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.