Hi welcome to Tear Down Tuesday huh? What's tear down Tuesday I hear you ask? Well I decided to add a bit of regularity to the blog. So every Tuesday Sydney time I'm going to do a tear down could be test gear, could occasionally be anything I don't know, it's a bit of test gear today. We all love test gear, but it's going to be a regular segment. Hopefully I can keep it up.

So every Tuesday from now on you can expect a tear down. What do we got today? H we've got bit of test gear vintage time. Uh, we' You've seen this uh briefly before and I promise that I do a tear down of it. So I'm going to do just that.

It's the Philips pm66 72 Got to get it right? Uh, 1 GHz counter timer or frequency counter. But they called these counter timers cuz they're actually capable of counting things. That's well, it's not just a frequency uh counter. it's capable of timing and Counting and doing all sorts of fun functions like that.

So you know what we say here on the Evev blog: Don't turn it on, take it apart. Let's go yeah and we'll just take a quick look at it. It's a classic8 digigit. uh L red LED display here and it's a time at counter.

It's got dual channels a& B. It's got a C input which is the high frequency one which goes from 70 MHz to 1 GHz The A& BS go to from DC to 120. mahz. It's got various uh trigger, uh sensitivity, uh stuff here and you can pull various things.

You've got time, 10 attenuators and slope and filters and uh, stuff like that. and it's got uh uh LEDs here to indicate uh, what range it's on either Herz Kerz Megaherz, Gigahertz or Nan micros and milliseconds and seconds for the uh time display. And it's got your other basic Uh controls like your Uh measurement time from 10 milliseconds all the way up to 96 uh seconds uh sample time and if you're frustrated, you can just push it to read it and uh, we're on the uh count uh capability here and uh, that's just allowing us to uh count up like that. um otherwise you can actually count uh the input.

so if you've you know you could count switch, bounce or you could count anything um, that you desire. It's got uh, pulse width of the A channel. it's got um, time average of the A and B time the period of a of course it does RPM It does frequency. it does the ratio between A and B and it does the phase between A and B in degrees.

It's quite a versatile instrument and if you go and have a look at the Uh manual for it and I'll link the manual in there. it uh, really is quite a flexible Beast I like it. look at that counting capability W On the back here we got a standard IC uh input put Power connector We've got a voltage uh selection switch over here and we've got uh the um a nice flexible uh capability is that you can um have an external frequency uh standard in or you can actually uh output the internal frequency standard out the 10 MHz standard because this thing does have the included option of the PM Uh 9690 High Stability oven stabilized 10 MHz reference oscillator and and it's got the gate monitor output here and external battery. uh, the battery pack I believe uh went inside there so you could uh Power this it would be uh, completely uh, portable.

You can get a rechargeable battery option and no surprises at all. Inside it's a classic uh construction you'd expect of an 80s uh era uh frequency counter like this one. we've got got our oven stabilized uh reference oscillator option up there we've got basically it's all dip and through hole. There's none of this uh, surface mount stuff cuz this would have been designed a lot earlier it would have been.

you know, a follow on from various uh previous models and things like that and an old school tape uh like uh PCB layout it only be double-sided classic green uh, crinkly solder mask I Love it! It's beautiful. We've got hand wiring over here and we've got it. Looks like a protection thing over the Uh Transformer And if we take a look at the Main's input stuff around here, there's a core type uh Transformer you don't see Uh that construction very often these days. Uh, exposed wiring down here on the Um IEC connector and the power switch as well.

Completely exposed. That's a no no these days. You got some main Fielder caps, you got a fuse. It's got a uh, it's warming.

It's warning you that there's a thermal fuse in there as well inside the Uh Transformer and there's a closeup of the strapping uh used to uh hold the core of the Transformer in there. and uh, haven't seen one of those in, uh, quite some time and my German viewers can get very excited there it is made in Germany the main filter caps. Brilliant. Haven't seen uh one of those uh can styles in H quite a long time either, and those can styles are somewhat out of place compared to the newer electrolytics.

There you go, they would, uh, still would not look out of place today. Now I'm not sure what this Uh Riser daughter board here does. It's uh, but um, clearly the date code 8922 22nd week 89. it clearly dates.

It's very similar for the other chips, so it clearly dates this design to uh, late 89, maybe early 90 build. And that's a signetics 10216. and that's a a triple high-speed differential amp. So uh, what? It's actually why they've gone and put that on a daughter board like that I Don't really know.

And there's another familiar chip, the Motorola MC 1016p and it's used in um, practically uh, most of the frequency counter kits back in the Uh 80s and things like that, probably even extending before that. I'm not sure when that chip first came around. it's a Uh, very similar to the other one. It's a triple Uh differential line receiver and it's used in the front end and uh, here it's used on the Um on the Uh inputs, on the Uh.

Back here and here's an old Uh Electronics Australia 50 MHz Frequency Counter Kit and you open it up and you have a look on the input and bingo, What do you have? The 1016? It was used in every frequency counter kit I think I ever saw. and there's the processor. It's an 8049 which is Uh based on the MCS 48 micro controller family from Intel. This is manufactured by NEC in Ireland Look at that.

Excellent. go the Irish and uh. this thing had uh, like half a Myips or a Myips uh processing capability. Um, reasonably good for its time in the AO 49 I believe actually has um two K of mask uh ROM built in as well.

so that's why you don't see any uh, memory actually. uh, surrounding that. although this window de, well, it's not really a window, but this device up in here looks like an An EO of sorts, but the number doesn't. uh doesn't ring a bell at all.

it's Oq4 Z so go figure. it could be some custom masked uh ROM or something like that. Perhaps because this 8049 processor did have the capability to um have an external ROM as well I believe. And we've got some uh, single turn adjustment pots in here for the 5vt rail measuring, time adjust, and uh, a couple of uh test points.

The hold off, uh, time, the hold off time adjust. That's a little uh test post there and uh, it looks like there's a missing uh pot in there. Another missing footprint here. So maybe um, I don't know.

Maybe there's a an optional upgraded model that has some additional capability. or they just left it out in the design, which is probably more likely 74. LS Logic and look at that. a little test jumper down there.

so I wonder what that does? I'm actually tempted to power the thing up with that uh test. Well, it's got a test. J It's got the jumper on there, so I'm tempted to power it up. uh, without the jumper on there and see what happens and I've done just that.

One interesting feature though, is it's actually got a standby LED on here. So it tells you that the power's plugged in and uh, let's power it on. I've got that test jumper taken off and hey, we got something. If we hit check, does nothing, reset, resets it display hold.

Ah, look at this. we've got like yeah, look at that. we've got it. allows you to adjust, it allows you to test the switches.

doesn't allow you to test the rotary stuff, but it certainly no, no. Anyway, it does allow you to test a few things to do with the switches by the looks of it, so it's not much functionality. uh there. but I guess yeah, it's it's certainly doing something.

I'm not sure if you can see that, but look at the green solder mask around there. you can see the uh, sort of like the crinkly, uh nature of it, uh, very common for this um, era and this uh, type of board. and uh, some of them actually had very bad solder masks that would actually uh, flake off with time as well and looking, what, uh, presumably is part of the level uh, control circuitry. This device looks pretty important.

It's a uh, AMD am, uh, 687 and you realize, eh, it's boring as badet. It's just a dual comparator. reasonably fast one, but a dual comparator nonetheless. And this section here has actually got a uh a shield around it mounted onto the board.

I Not uh, sure how massively, uh, effective that thing's going to be, but anyway, uh, there's a couple of single turn adjustment pots in there, there's a trimmer cap down in there, and uh, not much doing in there. And here's the knob. These are the input uh level control with the uh, pullout switch like that. so it's a it's a pot with one of these adjustable pullout switches try, uh, buying one of those if you had to replace it Buckley And apart from some other miscellaneous uh circuitry around here, couple of 4,000 series Seos, couple of um, other differential uh line receivers.

Not terribly exciting. We've got a uh, vertical, uh, front panel display board which handles the seven segment LCD So um, that's uh, pretty much all for the top. Really, it's not terribly, uh, exciting. It looks like we're going to have to take the bottom panel off and uh, have a look, there might be a board underneath.

Well, I Got to admit, that's pretty disappointing. I Expected a a bit more uh circuitry under there, but not. oh, we're got is the Uh PCB Mount push button switches on the front here and the optional uh 1 GHz uh board. and it's a dead giveaway because there's the there's the coax in there going through this connector.

Here onto the 1 GHz connector on the front and that's an optional. like if you uh, don't buy the the 1 GHz uh option, you wouldn't get the board or the connector. they just put the blank uh panel in there. but gee I don't know bit disappointed.

Expected something a bit more. some uh, jumper, uh some jumpers. uh down here, something going on there and uh, you set them based on the uh internal battery so all that space uh is probably taken up. The batter is probably that length like that and that's a 1 GHz input can and you'd expect there to be some circuitry in there, but if you actually have a look in there, there's not.

There's just some uh passive components in there and a couple of other through hole Ic's terribly boring. and those Ic's are the Sab 109 and the Sab 1046. Your guess is as good as mine and you can see that the front panel switch is just one of those classic open frame style. nothing unusual there at all now.

I'm kind of suspicious of that uh, gold capped, uh, what looked like sort of a mask ROM chip or something cuz there needs to be some other functionality on this board to uh do the timing and Counting uh capability. So I'm suspecting it might be some sort of Uh custom device. That's certainly what the Uh numbers on top might, uh, lead you to believe. Anyway, so as it turns out, you can actually download the full Uh service manual for this thing which has, um, the full schematic.

so we'll uh, go. It tells you all the various things. Here's our um. oven stabilized oscillator which will take a look at it's uh, you know, short term over the span of 24 hours.

We're talking 1 point less than 1.5 * 10 the -9 there. which is pretty good. It's this one here, the Uh 9690. You can even get a better one there with better shortterm and long-term stability.

Anyway, Um, let's go down and see if um, we can find the schematic, but there's other good stuff in here. There's all sorts of uh, formulas and things to tell you how it all works. Very nice if I Highly recommend even um, just having a browse of this to uh, figure out how uh, one of these time counters uh, works. It's got not bad stuff in there at all.

Anyway, what we want to do is go down here. bugger all the uh usage Tada Here we go. We got our schematic and uh, we looks like we're going to have to rotate this sucker around and uh, is this the one we want? This is our 672 that's the one we got. so um, over here is our Mains input.

There's our IC Mains input some Emi uh stuff. the Transformer the voltage selection switch standard full wave Bridge rectifier with some filtering. The external battery just goes through a 1 n43 there and then this section around here looks for all the world like a switch mode power supply. I Think you'll find that a TDA 1060 is a switch mode um controller.

so that and there's a 7905 up there and uh, some divider resistors there to set the output voltage. and uh, that's it for the power supply section. And if we take a look down here, we've got. Aha.

Here's our input. there's Channel a I Love these handdrawn schematics. they they're just great and it looks like it's been photo coped one too many times and and uh, roughly scanned and I don't know, faxed a few times and uh yeah I love it. Anyway, we've got our BNC input here Channel A our selectable AC uh DC coupling there our selectable input attenuator with the uh trimmer cap there to trim that out and uh, looks like we've got some clamping diodes here.

um, that looks like that's our what tells you that's the 50 khz filter. They even switch that in or you can bypass it by going around there and that goes into the uh am, um uh, the the uh fast comparator there. so that's pretty much all there is and you'll find that the other the input the other input to the comparator will come from Tada No surprise, your trigger level sensitivity knob. There it is.

so you set your trigger level and that's pretty much all you uh, need to uh, sense the put there so that's pretty darn easy. and here you go: I Think we've found the meat of it that looks like the process of the 8049 and that's hooked into the display system over here. Here's the uh, it's the multiplexed um 8 digigit display there and it's got uh, there's the driver transistors for it and it's multiplexed in both ways so that's how you can, uh, drive that 8-digit display with only looks like they've got eight lines there, so so really easy to actually drive that. and that means you don't need many pins on your micro.

but aha, look at what we have here. Lookie lookie lookie O O was at 4 Z that I think that's what that uh custom chip was and it looks about right. Based on the uh, it was like a 28 pin device and that goes up to 20 28. There we go.

So that is a custom device it is. It's got things like decade, uh, what is that TBD counter scan clock the data clock. so that is obviously some custom uh LSI device which uh, implements all the um timer counter functions basically. uh, we got divider there and uh, that's yeah.

Looks like all the magic happens inside that custom LSI device I wonder how old that is? It might have been used in uh, previous Uh models? maybe? who knows and they just carried it over to this model. That wouldn't be surprising. And looky, what we have here. we have two seven, triple FS not regular triple FS but they've put in the uh, seamos version and uh, this one here is the uh measurement, uh time.

That's the measurement uh, gating time, uh pot On the front panel, there's the control there and uh, that just uh controls, uh, the amount of uh time that it requires to take a measurement and the other one here is the hold off. uh time? It looks like the hold off is not available. Function is not available in in, um, other versions. So there you go.

triple FS They're everywhere. and obviously here's the 1 GHz uh option board cuz here's the coax uh, input over here. it's AC coupled and those uh, passive components around. There were the ones that were, uh, inside the can and then we' got our S19 as we mentioned in our Sub 1046 and that's obviously some sort of uh, prescaler circuitry cuz that's basically all a 1 gigahertz option board would be would be a front end.

uh, prescaler to divide uh, the high frequency down to the lower frequency that the regular Uh frequency counter circuit is capable of handling. And as for this, uh Oven Oscillator here I've done I There were two screws on the bottom I've undone those and I think it just pops, it just pops off. Oh yes, there we go. Taada! It's just got A.1 in header and that's where the existing Crystal goes.

If you just get the standard option, that's the standard Crystal and it's even got a note saying please remove the crystal when you're installing this um oscillator module and this High Stability Oven Oscillator Module 10 MHz it it The option must have cost like a you know, almost $1,000 maybe or $500 or $1,000 or something like that. So let's crack this thing open and uh, see what's inside And perhaps no surprise inside, we have some foam. very hard cell, uh stuff. It's certainly not soft and that's what.

uh uh, you know keeps uh, this thing uh, uh, thermally stable inside. or it, uh, is going to help a great deal. So I think we need to take the screws off the other end. Now let's see if we can take this thing out.

Look, there's a uh flat Flex cable there going down into the foam CER sandwich. So the crystal is going to be down in the foam sandwich. I'm going to do my best not to, uh, physically stress this thing. There's a regulator bolted on the Uh on the back.

Oh, that's a some sort of regulator. There's the 10 turn trim pot there for the fine adjustment. There's a coarse adjustment in here somewhere as well. So let's take this thing open and there's our course adjustment.

There's another board in there, presumably. oh, what's that? Tada Oh, look at that magic can now. I'm thinking that I would be quite silly to try and take this can apart. uh, but I should be able to lift it out of there, perhaps gently.

This is rather rather fascinating. Look at that. They've gone to all the trouble to add that flat Flex cable on there, going down to both ends like that and there'd be like a um, an Sc, you know, or a standard cut crystal. Um, inside there.

And there's obviously a uh, a temp sensor there which keeps it all regulated. There'd be a heater inside there as well, cuz these things draw like 10 watts or something like that, you know? 5 Watts They they draw uh, quite a lot of power to keep these to get this thing up to temperature and keep it there. And that's why they need the foam to, uh, um, make it immune to um, outside thermal shocks and things like that. So there you go.

There's a I Guess we could, oh, try and take that off I Don't know I Want to keep this intact? Really? I want to keep it functional. You can see that there appears to be quite some circuitry inside there, so it's all a rather complicated and convoluted, uh construction. It's really, really unusual, but uh, there you go. That's the course adjustment pot on the top.

Ah, what the heck. Nothing ventured, Nothing gained. I've taken the uh spring clip off that and I'm going to see if I can potentially uh, lever this top. Yep, it's gone pop.

Tada Bingo Look at that. We're in. we're in. So screw the timer counter.

This is the most interesting thing we've seen today and there it is You can. You can see the Uh Crystal here under this copper shield and it's a quite a large case. I can't remember the name of that uh case off hand. It's a very, Uh large old style one and there's some circuitry on there.

Looks like probably a transistor. uh, something like that. But the real interesting thing is I See right down the bottom in there. not sure if you can see it.

there's a ceramic, what looks like a ceramic hybrid piece CB underneath the crystal? Wow. I Really don't think I'm going to have much luck cracking this thing open any further without. uh, some major drama. but you can see a couple of surface mount devices on the hybrid down there and another.

Not sure if you can see it right down in there, but uh, yeah, there's definitely, And that looks like for all the world, like a ceramic hybrid ceramic board. So why would they be using a ceramic hybrid board? Well, my guess is uh, temperature thermal stability? because uh, ceramic hybrid boards are very stable. um, in terms of uh, temperature. So there's no uh, expansion or anything like that.

So uh, really, that would be my guess as to, uh, how they why they've actually put that uh, hybrid board down in there. but I Don't know if you've got a better idea? Let me know. leave it in the comments and clearly that's going to be our heater there. And that's our temperature sensor which is, um, curiously, um, actually on the outside of the case like that rather than the inside.

Go figure. But that's uh, that's clearly the uh heater element with the feedback and that would, uh, regulate the temperature inside. This can. Well, there you go I hope you enjoyed that.

I think that was the uh icing on the cake there with that oven uh, stabilized oscillator. That was excellent because well, quite frankly, the timer counter was boring. as bad as you know. I that's pretty much what I expected.

really? um, time counters aren't really that exciting pieces of Kit because it's basically just a microprocessor. some uh input, um uh, differential amps, comparators, and uh uh, dividers and things like that and well, you know it just divides it down and and measur is it with an against a reference oscillator, some gating and stuff like that. not rocket science so you can see why. these actually uh probably cost a fair bit cuz each one would have been individually uh, hand assembled, hand tweaked by a guy with a long Gray beard and he Strokes it and gets a tongue angle right and he trims the uh, the course and the fine uh trim pots and they and they would have soaked it in and measured it and ah, you know characterized the thing so you can see why these actually cost the money.

I like it so and if you like the video, give it a thumbs up please cuz that really helps with the Uh rankings and things like that. and uh, if you uh want to comment on this, jump over to the Evev blog forum and if you like the uh, tear down Tuesday idea let me know and I'll keep it up but I'll probably keep it up anyway. Want it to be a regular thing so catch you next time and.