Did you notice the big blue edge connector alongside that big row of 7475 latches? And there's a gap in the metalwork of the chassis just behind it, leaving a clear path to the rear panel. On the rear panel are blanking plates for the digital output connectors (optional). So my guess is that the edge connector is used to connect to a PCB and/or wiring harness that leads out the back for the digital output interface. Also, the RECYCLE RATE control was set to 'infinity', which is why Dave had to keep pressing the RESET button to get a reading. Turning that rate control clockwise would make it auto-refresh.
Sent you an PM Dave via the forum regarding a manual. I love the build quality on this vintage test gear, it's very similar to HP stuff of the same era. I had a HP3770B telephone analyser that used the same construction, IE horizontal bottom bus board with vertical cards, it used the same type of plastic clips to secure the card, heavy gold plating, etc.. Thanks for another cracking video.
The ovenized oscillator heat has probably killed the multi turn trimmer inside it, I have found that the heat tends to make the plastic go brittle and they break when turned all the way to the end, pull the oven apart and replace the trimmer, I have done this myself on a Marconi 2305.
I too am betting that nothing is coming out of that oven. Put a scope on it to verify then rip it apart. That's what you get for turning it on before you took it apart.
I don't have much experience with professional gear but from what I have seen, I do agree that trimmer pots often go brittle near heat sources. I have seen them in 70s tube radios and old televisions. Just a bit of tweak and the entire end part just separates
I was working in a major electronics plating plant in the 1972-1973 years and gold was about $45 US an ounce. We didn't plate cicuit boards but did plate *millions* of IC lead frames monthly. Generally, the gold plating was from 15 to 40 microinches thick. We also plated flat wire for Sprauge that had a (IRC) gold plating of 200 micrroinches and another flat wire, silver plate of 350 microinches. We plated *miles* of that wire. Just thought I'd add some relevent historical info....
Yes, but it's not very usable. The fast mode is completely unusable, you never get a displayed reading long enough to read it, and the slow mode is agonisingly slow to auto-refresh.
@@EEVblog Dave - at least with the HP counters I have, if you turn the 'storage' switch on the rear panel to the on position, rather than counting up from zero with each new reading as it's doing in the video, it will hold the last reading as it takes the next one, and only update the display as it gets new readings.
this is waaaay before my time, but it's always interesting to see how they did things without a computer or any of the tools we have today. well laid out boards from back in the day really are a work of art.
I bought something similar from an electronics surplus store. The front of that device looks very similar. I only bought the thing for the nixie tubes and drivers. Cost me 25.00 dollars. It actually worked. Very cool vintage!
I agree Dave, Systron Donner are very well built inside, not a well known popular name, but I have used the frequency GHz counter of Systron Donner and they do work very well,
They used a combination of 5V DTL and 5V TTL for the unit. I suspect that the TTL is used in the "high speed" part of the unit. DTL was a predecessor logic but was rapidly replaced by TTL. By 1970 DTL was very out of favor, and probably not used in new designs. TTL had more MSI parts, especially the 7490 decade counters used. Just a bit of history.
I have that EXACT same model up here in Brisbane, except that the gate is stuck high. Bought the service manual for the model down from a bloke in the USA for $70 plus shipping. Only difference between the two models is the A12 and A16 modules. Fun fact, the A12 module handles the gate! If you have any manual/schematics for the modules I'd love to see them.
A high definition digital SLR camera can be a shortcut these days. Take the snap, import into the right SW, OCR the labels and drop into place as text. Sometimes even the same software that's meant to handle the scanned images can process the digital picture exactly as if you'd scanned it; all that needs be done is to convert it into the correct file format and import.
My university still has a massive bit of tech from systron donner sitting on display near the main entrance. Also found a machine labelled "Applied Dynamics International AD 100". My university is the university of Stellenbosch in South Africa and the specific building is the engineering building.
I was on holiday in LA and went to Apex electronics. I bought an almost identical Systron Donner counter and had to buy a second suitcase to take it home!
The construction is really similar to the HP 5245L frequency counter, with the daughterboards, nixie tube display, crystal oven oscillator and even the fan at the back. The first revision of that model appeared around 1965.
Great teardown. I am loving this new 'old school Eevblog' era with the Mailbag Monday and Teardown Tuesday; what about Fundamental Fridays?. This is more like the channel I loved when I just found your videos. Around video 700.
The blue makes it go faster... GOTTA GO FAST :D ALways interesting to see these older electronics being taken apart considering the amount of discreate electronics and meriad of chips in older stuff verses the highly intergrated electronics of today with crap tons of boring surface mount components.
System Donner really had a thing for those thumb wheel switches. Strangely I made a video about cleaning out my workshop last week looking at one of their RF signal generators. They really are a thing of beauty and built like a brick poo house. I wonder if the company was part of the Thorne EMI group as the one I have is badged up on the back. The construction of my signal generator looks just like your counter inside. It’s very very heavy with large fanless linear PSU. The signal generator also has a similar oven controlled oscillator. I didn’t realise they were manufactured in Australia as my manual was printed in the USA.
ITT International Telephone & Telegraph. My dad worked for their division called Cannon Electric, the originator of the cannon plug used widely in the film TV and music industries, commonly known these days as XLR.
When I worked for Motorola starting in 1979, our communications service monitors were made by Systron Donner (even though it said Motorola all over it). Back then, it was really good stuff.
Cool piece of Tech. I think you will find that the reason for only one extender board is because all of the cards are 25 x 2 i.e. 50 way card edge connectors.
I picked up a 6150 at a flea market a couple years ago. It came with only seven digits; I added the 8th and 9th. It's only a 50MHz counter (6151=200MHz) so the 9th digit is of dubious value. I did manage to push it to 67MHz, but it's very fussy up there. I don't have the extender nor the thumbwheels (must be an option) but I do have the digital output wiring harnesses. If you don't like to watch it count, use the storage switch on the back and it behaves like modern counters. Recycle rate and fast/slow will press reset for you every so often. :-)
The Defpom's Repair Channel I’m surprised by the Australian manufacture. I had assumed they were American and the Thorne EMI connection is interesting.
Looking at the front my guess would be the two thumb wheels are counts before start, counts to stop... if you measuring a physical device, that not an exact frequency... the start would be for spin up(the first 30 pulses are slow, because that how long it takes to get to speed) and take the time for the next 20 pulses to determine the rate...
Loving the original 7400 series logic! Talk about power supply spikes and current draw with those puppies! Love the vintage DTL logic also! Just try to buy a DTL logic gate these days!
17:50 I can't be sure because I don't have the same machine, but I'll bet that you can use the extender card for all boards in the unit. The shorter and longer daughter boards have the same number of pins and the extender has all keys cut into it.
One day I'll probably send you industrial multimeter I got few years ago. I heard it was used by company which made industrial temperature sensors, but calibration was slowly drifting away and after few years they weren't able to offset it enough to fit into accuracy they expected. Internal construction looks similar to this counter, one big motherboard and few smaller boards in slots, every board for specific task. Manual nicely explains what every board does and how it works all together (but only in Czech). Originally I wanted to use it at home, but it takes a lot of precious space on table and although you can control it via external interface, it's still pretty big for me, even sitting under table. Also it's probably impossible to offset everything to make it measure precisely and calibration would be pretty expensive with no warranty it will measure correctly after few months.
Finally, conclusive proof that despite it feeling like time went slower when we were kids, well, actually it didn't! 10MHz in 1973 is pretty much 10MHZ in 2018 too ;-)
Hey! I see you liked this kit... have you ever been contacted by an engineer of a legacy device you tore down? That would be fascinating to hear about!
You didn't mention the most important part!!! THE SMELL!!! Mine emits that "early 70s" smell - a bit more nuanced than my Tek 453A, but definitely a great smell. Wish I had a service and operation manual. I've been patiently waiting for this vid, since I saw you grab that in the warehouse! I have a 6153 (still in cal as of 2014 by Tek!) and it's still spot on as well. Mine actually doesn't have the thumbwheels, but instead has a "D" input, which is the 3GHz input (and is a bit more interesting than the thumbwheel board, but not as cool); the input board has the same individual wires going over to a 14 pin DIP socket plugged into board A15 (the one your thumbwheel switches terminate to) - exactly like the ones on the display/control board. Interestingly, mine also has the "High stability" Motorola oscillator. Also, most of the chips in mine are 71, but some date codes are 69! I need to check the other one I have (I used it for spare nixies for mine - it didn't have the "High Stability" osc). Also, my A10 board isn't blue, I'm sad :)
I've got a piece of vintage oddware in my collection I might send (and it has one small fault too) Surely would make an interesting teardown. Can't find anything on the 'net about it. Gonna take several hundred bucks to ship it from the US though!
Gorgeous, I was 10 when this was made. Do you have to keep pressing Reset to get it to work? My ancient Nixie counter just counts as soon as it has an input high enough.
Amazing how seriously fast and accurate old tech is, I miss the golden age of extremely well thought out hardware. It’s just boring when literally everything today is cookie cutter micro-controller and CPU based.
I think the reason for the supplied extender card is that you need it for calibration. All those adjustments on the PCBs can only be reached when they're on the extender. So the designers included a parking space for an extender card, and supplied one, so that calibrations could be done.
Likely there from the factory - it was in its own little hidey-hole. I have a few pieces of old HP kit that included an extender - a 4270A capacitance bridge comes immediately to mind, and I think there was another but I cant think of it at the moment. The extenders are worth their weight in gold if you need to troubleshoot!
I recently did a few teardowns/circuit studies on a small collection of 1970s frequency counters, from Heathkit to Sabtronics to some others, and Dave is right....the darn Motorola MC10116 triple differential line amplifier IC is in the front end of all of them. AND, the surrounding circuits are virtually identical as well......almost like every manufacturer just copied the same Motorola application note circuit.......even the interconnections between the three amps is pin-for-pin identical. But try to really learn how the IC is supposed to work, using only the Motorola datasheet, and you won't get very far. Perhaps Motorola had a separate book that provided more applications information than the datasheet does. It seems like this should be a fringe application for the chip, since being the front end of a frequency counter is not its "rai·son d'ê·tre"; it is intended to be a differential line amplifier for transmission line applications.
You surprised by the extender card, I have an AWA-f240 distortion/noise meter and they included an Alen key and spare Din plug inside the case!!! I posted some images at EEVblog a couple of months ago... www.eevblog.com/forum/repair/vintage-awa-f240-awa240-distortion-and-noise-meter-repair/ check image 4.jpg
Did you notice the big blue edge connector alongside that big row of 7475 latches? And there's a gap in the metalwork of the chassis just behind it, leaving a clear path to the rear panel. On the rear panel are blanking plates for the digital output connectors (optional). So my guess is that the edge connector is used to connect to a PCB and/or wiring harness that leads out the back for the digital output interface.
Also, the RECYCLE RATE control was set to 'infinity', which is why Dave had to keep pressing the RESET button to get a reading. Turning that rate control clockwise would make it auto-refresh.
Those Nixie tubes just look beautifull!
Sent you an PM Dave via the forum regarding a manual. I love the build quality on this vintage test gear, it's very similar to HP stuff of the same era. I had a HP3770B telephone analyser that used the same construction, IE horizontal bottom bus board with vertical cards, it used the same type of plastic clips to secure the card, heavy gold plating, etc..
Thanks for another cracking video.
The ovenized oscillator heat has probably killed the multi turn trimmer inside it, I have found that the heat tends to make the plastic go brittle and they break when turned all the way to the end, pull the oven apart and replace the trimmer, I have done this myself on a Marconi 2305.
I too am betting that nothing is coming out of that oven. Put a scope on it to verify then rip it apart. That's what you get for turning it on before you took it apart.
I don't have much experience with professional gear but from what I have seen, I do agree that trimmer pots often go brittle near heat sources. I have seen them in 70s tube radios and old televisions. Just a bit of tweak and the entire end part just separates
I was working in a major electronics plating plant in the 1972-1973 years and gold was about $45 US an ounce. We didn't plate cicuit boards but did plate *millions* of IC lead frames monthly. Generally, the gold plating was from 15 to 40 microinches thick. We also plated flat wire for Sprauge that had a (IRC) gold plating of 200 micrroinches and another flat wire, silver plate of 350 microinches. We plated *miles* of that wire.
Just thought I'd add some relevent historical info....
72 it was around 50-60, in 73 it jumped to about 110 (atleast according to the records I found)
$45 in 72? that would be a lot of modern dollars
Wasn't sure whether to watch this one but glad i did. Great teardown and the display is very nice. enjoyed every minute.
Taking the "recycle rate" pot off the "infinite" setting will prevent you from having to hit reset for each gate...
I was wondering if he would notice, and never did.
Yes, but it's not very usable. The fast mode is completely unusable, you never get a displayed reading long enough to read it, and the slow mode is agonisingly slow to auto-refresh.
@@EEVblog Dave - at least with the HP counters I have, if you turn the 'storage' switch on the rear panel to the on position, rather than counting up from zero with each new reading as it's doing in the video, it will hold the last reading as it takes the next one, and only update the display as it gets new readings.
Beautiful, Dave! Thanks for saving and sharing it!
you have to appreciate the effort that has gone into designing this product :)
this is waaaay before my time, but it's always interesting to see how they did things without a computer or any of the tools we have today. well laid out boards from back in the day really are a work of art.
I bought something similar from an electronics surplus store. The front of that device looks very similar. I only bought the thing for the nixie tubes and drivers. Cost me 25.00 dollars. It actually worked. Very cool vintage!
I need to say that this is the most beautiful board layouts / colorful / easy to see what I ever see so fare (: I like it !!
You' re right, they certainly don't make them like that anymore. It is absolutely beautiful.
I agree Dave, Systron Donner are very well built inside, not a well known popular name, but I have used the frequency GHz counter of Systron Donner and they do work very well,
They used a combination of 5V DTL and 5V TTL for the unit. I suspect that the TTL is used in the "high speed" part of the unit. DTL was a predecessor logic but was rapidly replaced by TTL. By 1970 DTL was very out of favor, and probably not used in new designs. TTL had more MSI parts, especially the 7490 decade counters used. Just a bit of history.
That was a magical Nixie moment for sure!
Man, something about 1970s tech. Absolutely gorgeous
thats an impressive amount of gold...but its a thing of beauty! it needs to survive for Sagans kids to see!
I have that EXACT same model up here in Brisbane, except that the gate is stuck high. Bought the service manual for the model down from a bloke in the USA for $70 plus shipping. Only difference between the two models is the A12 and A16 modules. Fun fact, the A12 module handles the gate! If you have any manual/schematics for the modules I'd love to see them.
Have you scanned and uploaded the service manual that you have?
@@userPrehistoricman I have not. It has a lot of foldout sections for schematics. I do intend to, but it's a big job.
A high definition digital SLR camera can be a shortcut these days. Take the snap, import into the right SW, OCR the labels and drop into place as text. Sometimes even the same software that's meant to handle the scanned images can process the digital picture exactly as if you'd scanned it; all that needs be done is to convert it into the correct file format and import.
My university still has a massive bit of tech from systron donner sitting on display near the main entrance.
Also found a machine labelled "Applied Dynamics International AD 100". My university is the university of Stellenbosch in South Africa and the specific building is the engineering building.
I was on holiday in LA and went to Apex electronics. I bought an almost identical Systron Donner counter and had to buy a second suitcase to take it home!
The construction is really similar to the HP 5245L frequency counter, with the daughterboards, nixie tube display, crystal oven oscillator and even the fan at the back. The first revision of that model appeared around 1965.
Great teardown. I am loving this new 'old school Eevblog' era with the Mailbag Monday and Teardown Tuesday; what about Fundamental Fridays?. This is more like the channel I loved when I just found your videos. Around video 700.
The blue makes it go faster... GOTTA GO FAST :D
ALways interesting to see these older electronics being taken apart considering the amount of discreate electronics and meriad of chips in older stuff verses the highly intergrated electronics of today with crap tons of boring surface mount components.
System Donner really had a thing for those thumb wheel switches. Strangely I made a video about cleaning out my workshop last week looking at one of their RF signal generators. They really are a thing of beauty and built like a brick poo house. I wonder if the company was part of the Thorne EMI group as the one I have is badged up on the back. The construction of my signal generator looks just like your counter inside. It’s very very heavy with large fanless linear PSU. The signal generator also has a similar oven controlled oscillator. I didn’t realise they were manufactured in Australia as my manual was printed in the USA.
ITT International Telephone & Telegraph.
My dad worked for their division called Cannon Electric, the originator of the cannon plug used widely in the film TV and music industries, commonly known these days as XLR.
What a beauty. I want one just for that display updating~
When I worked for Motorola starting in 1979, our communications service monitors were made by Systron Donner (even though it said Motorola all over it). Back then, it was really good stuff.
Cool piece of Tech.
I think you will find that the reason for only one extender board is because all of the cards are 25 x 2 i.e. 50 way card edge connectors.
I picked up a 6150 at a flea market a couple years ago. It came with only seven digits; I added the 8th and 9th. It's only a 50MHz counter (6151=200MHz) so the 9th digit is of dubious value. I did manage to push it to 67MHz, but it's very fussy up there. I don't have the extender nor the thumbwheels (must be an option) but I do have the digital output wiring harnesses. If you don't like to watch it count, use the storage switch on the back and it behaves like modern counters. Recycle rate and fast/slow will press reset for you every so often. :-)
I just saw another Systron Donner unit this morning, AllTheGearNoIdea did one, a RF generator.
The Defpom's Repair Channel I’m surprised by the Australian manufacture. I had assumed they were American and the Thorne EMI connection is interesting.
My frequency counter is a Nixie one. Can't beat retro test gear, modern stuff does not hole a candal to it.
Mine is a SE SM200 MK2. Lovely machine.
I love the old school test gear.
All these card slots, all that gold. D:
Really beautiful and organized.
I worked on stuff that shipped with an extender card.
There was an optional kit of spare PCBs you could get oo.
Looking at the front my guess would be the two thumb wheels are counts before start, counts to stop... if you measuring a physical device, that not an exact frequency... the start would be for spin up(the first 30 pulses are slow, because that how long it takes to get to speed) and take the time for the next 20 pulses to determine the rate...
Loving the original 7400 series logic! Talk about power supply spikes and current draw with those puppies! Love the vintage DTL logic also! Just try to buy a DTL logic gate these days!
Not a single microprocessor in it, all discreet logic...beautiful
17:50 I can't be sure because I don't have the same machine, but I'll bet that you can use the extender card for all boards in the unit. The shorter and longer daughter boards have the same number of pins and the extender has all keys cut into it.
One day I'll probably send you industrial multimeter I got few years ago. I heard it was used by company which made industrial temperature sensors, but calibration was slowly drifting away and after few years they weren't able to offset it enough to fit into accuracy they expected.
Internal construction looks similar to this counter, one big motherboard and few smaller boards in slots, every board for specific task. Manual nicely explains what every board does and how it works all together (but only in Czech).
Originally I wanted to use it at home, but it takes a lot of precious space on table and although you can control it via external interface, it's still pretty big for me, even sitting under table. Also it's probably impossible to offset everything to make it measure precisely and calibration would be pretty expensive with no warranty it will measure correctly after few months.
Nixie goodness. Nice. OMG it works!
I still use a similar counter, great piece of kit!
Never used one but learned how to build one, and in the exam one of the questions was to draw the diagram
Looks to me Dave that the extender card works for both the longer and shorter cards. The longer cards seem to have the same 25 pin connector.
"I need to RTFM ... if I can find the FM". Best..quote..ever
Finally, conclusive proof that despite it feeling like time went slower when we were kids, well, actually it didn't! 10MHz in 1973 is pretty much 10MHZ in 2018 too ;-)
Hey! I see you liked this kit... have you ever been contacted by an engineer of a legacy device you tore down? That would be fascinating to hear about!
@@Okurka. :cry:
That thing is older than me.
Loved the hand drawn tracks - almost psychedelic style - reminds me of a Rick Wakeman album cover!
Dead Dingo's Donger LOL
Half a bee's dick!
You didn't mention the most important part!!! THE SMELL!!! Mine emits that "early 70s" smell - a bit more nuanced than my Tek 453A, but definitely a great smell. Wish I had a service and operation manual.
I've been patiently waiting for this vid, since I saw you grab that in the warehouse! I have a 6153 (still in cal as of 2014 by Tek!) and it's still spot on as well. Mine actually doesn't have the thumbwheels, but instead has a "D" input, which is the 3GHz input (and is a bit more interesting than the thumbwheel board, but not as cool); the input board has the same individual wires going over to a 14 pin DIP socket plugged into board A15 (the one your thumbwheel switches terminate to) - exactly like the ones on the display/control board. Interestingly, mine also has the "High stability" Motorola oscillator. Also, most of the chips in mine are 71, but some date codes are 69! I need to check the other one I have (I used it for spare nixies for mine - it didn't have the "High Stability" osc). Also, my A10 board isn't blue, I'm sad :)
I'll swap you a blue board for the 69 chips
Thinking of the 11C90 prescaler. ONLY +10 prescaler left is one section of the MC12080 (+10, +20, +40) I think problem with OCXO is oven was COLD,
Perfektní provedení dané konstrukce.
i have one!!! it's awesome with nixie tubes!
18:20 of course it works.... these usually do until someone does a clean+recap job on them :)
19:27 Try adjusting 'Recycle Rate' away from infinity. Also Fast/Slow would be helpful.
Gold pre 1972 was fairly cheep, 73 and up it was on the rise.
I kinda knew it would work. So cool !
I think the ovenized oscillator might have a vacuum tube inside ?, tear it down Dave :D
S@x on a stick! (: And a beautiful showdown of retroTech precision at the end, brilliant! :)
3:05 It almost looks like you are supposed to rearrange those boards into maze walls for a mouse to find his way through.
I have a smaller counter from this maker from the same date and the oven oscillator unit looks to be identical
A thing of beauty :)
You. Sir, are easily amused. It takes, at least, a tube amp or preamp for me. 😎
Looks pretty advanced for 1973
Wow a dedicated Australian made Donner kebab meat counter/timer.
I've got a piece of vintage oddware in my collection I might send (and it has one small fault too)
Surely would make an interesting teardown. Can't find anything on the 'net about it. Gonna take several hundred bucks to ship it from the US though!
I wish my 7603 had an extender card in it. Damn things go for more than the scope is worth on ebay, I had to make one!
10:35 super high impedance relays and stuff. Pre/Bal, sounds like a chopper amp.
8:38
One of these transistors is not like the others...
Such a gorgeous Nixie glow mmmmmmmmm!
25:17, perhaps it has pulldown-to-internal for if the external reference fails. (my uncle's camcorder had the same thing with the mike-in)
You are feeding a GPS Trimmed Rb Clock source to a poor 197x frequency counter... That is insane!
Awesome !!!
Modern scopes are not worth taking apart because there is nothing in them, but this was fun because it's packed.
For a second I misread the title and thought that dave was tearing down a shawarma cutter.
19:04 Awesome 👍👍👍👍
Systron Donner used to make good quality analog computers back in the day . . .
Gotta stuff the oven oscillator up the counter own clacker? Set up to share that oven reference with other equipment?
I have two of those from Beckman!
I have a couple of the SD 100A pulse generators.
Surprised to see that the chips were not socketed.
"The Leader of Quartz MEMS Inertial Systems for Aerospace and Defense Applications".
:)
SO many opportunities to DAVE CAD that :O
14:22, looks like you have the option for an extra ninth digit.
Gorgeous, I was 10 when this was made. Do you have to keep pressing Reset to get it to work? My ancient Nixie counter just counts as soon as it has an input high enough.
Amazing how seriously fast and accurate old tech is, I miss the golden age of extremely well thought out hardware. It’s just boring when literally everything today is cookie cutter micro-controller and CPU based.
Supplying an extender card?
I bet the previous tech forgot it there! :)
I think the reason for the supplied extender card is that you need it for calibration. All those adjustments on the PCBs can only be reached when they're on the extender. So the designers included a parking space for an extender card, and supplied one, so that calibrations could be done.
I bet it's standard issue. Also, there is a nice slot for storing it, that's not a coincidence.
Likely there from the factory - it was in its own little hidey-hole. I have a few pieces of old HP kit that included an extender - a 4270A capacitance bridge comes immediately to mind, and I think there was another but I cant think of it at the moment. The extenders are worth their weight in gold if you need to troubleshoot!
I want one!
Gold flash (0.0x microns) on some connectors!
I recently did a few teardowns/circuit studies on a small collection of 1970s frequency counters, from Heathkit to Sabtronics to some others, and Dave is right....the darn Motorola MC10116 triple differential line amplifier IC is in the front end of all of them. AND, the surrounding circuits are virtually identical as well......almost like every manufacturer just copied the same Motorola application note circuit.......even the interconnections between the three amps is pin-for-pin identical.
But try to really learn how the IC is supposed to work, using only the Motorola datasheet, and you won't get very far. Perhaps Motorola had a separate book that provided more applications information than the datasheet does.
It seems like this should be a fringe application for the chip, since being the front end of a frequency counter is not its "rai·son d'ê·tre"; it is intended to be a differential line amplifier for transmission line applications.
It looks like that extender card would work on all boards. (no. I didn't count the pins.)
Love it. Anyone care to estimate the value of the gold in that thing?
Aprox 2g, 3g at most. Maybe less, surly not more.
You surprised by the extender card, I have an AWA-f240 distortion/noise meter and they included an Alen key and spare Din plug inside the case!!! I posted some images at EEVblog a couple of months ago... www.eevblog.com/forum/repair/vintage-awa-f240-awa240-distortion-and-noise-meter-repair/
check image 4.jpg
What package are those round black blob transistors? Was it a standard in the 70's?
18:57 i hear in my head the noise caused by the counter.
I'm still using a systron donner 3 channel power supply
Hmm.
Can you get your hands on a Brüel&Kjær 2113 frequency spectrometer.
Would be great. :D
please make a high speed video of the nixi tubes going so fast.
Very surprising you can't set a gate /sample period automatically?