Systron Donner 6054B frequency Counter 20Hz-18GHz 1980

Added: 2026-05-10

[00:00:01]Welcome to a new test and tearown video.

[00:00:05]This time it's a Cistron Donna frequency counter model 6054B.

[00:00:16]This one got two inputs.

[00:00:20]20 Hz to 20 MGHertz and then the fast one is 20 MHz to 18 GHz.

[00:00:32]I spent the last few hours washing and polishing and making it nice and re [laughter] and presentable here for for the video. So now it's nice and shiny. I even used a little permanent marker on all those little dents here. So, from a distance like this, it looks pretty nice and fine, but I will show here how it was before.

[00:01:01]Something like this. Ah, it's completely out of focus.

[00:01:08]Ah, damn it.

[00:01:10]So it was looking more or less like that all over the the place full of scratches and all that because it really had a long hard life. It is from about 1970.

[00:01:25]Here at the back we can see the ILE E interface and we got individual little switches here to set up the address and the program can be in talk only. Hm.

[00:01:39]Interesting.

[00:01:40]And we got the usual reference in out stuff.

[00:01:46]What is that?

[00:01:48]Discriminator output. Oh, so it's using some sort of a receiver front end method for the 18 GHz. That's interesting. I look forward to play with that. I was doing a little bit of googling around. I can't find any kind of manuals or schematics or anything at all uh on this model.

[00:02:11]I also put it on my scale and it is 14.8 kilos.

[00:02:18]Oh yeah, what I found was there's one on eBay for about $500. So, well, that is just what somebody thinks it is worth.

[00:02:27]Uh doesn't really tell me a lot, does it? So, now I'm starting to understand why it is so heavy.

[00:02:36]Of course, the transformer is quite big.

[00:02:41]And we got another little transformer.

[00:02:43]That will be the oscillator unit. We got some screws here you can remove. Then you can access some trimmers.

[00:02:51]There's a little note here about some repair.

[00:02:54]>> [snorts] >> And um that will be the power supply or at least the capacitors and diodes which see the transistors down there and another capacitor. And you don't see any connectors around here. So if you want to service this, all you have to do is just screw this and then you can flip this up and then you can put it down like that. And then there's Yeah. And also if you look at the all the wires that goes here and between all this, they are soldered on the top as well as we see some connectors here at the bottom.

[00:03:33]Yeah, those big hefty connectors to the motherboard for some other wires that's connecting everything like that, right?

[00:03:41]We see tons of signals going to the front. That's probably the this place.

[00:03:49]But this is not super service friendly with all the wires here. You can't really pull all these up unless you pull some more stuff apart.

[00:04:01]This is a little bit funny.

[00:04:03]And then we got four mystery boxes.

[00:04:07]And this is of course the 18 GHz input.

[00:04:11]And this is probably a mixer or something like that. And then we have a little power divider. And then we have two more mixers or something like that.

[00:04:20]Right.

[00:04:21]So some of these that will probably be generators and some will be detectors.

[00:04:28]I hope to figure this out.

[00:04:31]This Oh yeah, we have to have another circuit board under here. And we also have Yeah, to have some more stuff related to the power supply. So yeah, we we definitely need to open the bottom as well to get a little bit bigger understanding of what is going on here.

[00:04:48]Here at the bottom, sorry, there's actually surprisingly a lot of stuff going on here. So here at the power supply, this is controlled by this or where is the controlling devices for those transistors that I've seen? There's probably a board somewhere that is uh doing something with those. We got a little bit more regulators uh going on here.

[00:05:19]That uh transformer there. I believe this is the standby power supply for the oven because we got two sets of fuses.

[00:05:27]One is the oven and one is the main supply. So yeah, this is a pretty good uh yeah, I think this is a good explanation for that. And um we got some more local regulators probably for all this uh RF section.

[00:05:45]Here we got some screws. That will be the release for the RF mystery boxes.

[00:05:53]And here one of the RF boxes probably a mixer. So this is the mixer output.

[00:06:02]And then it goes. There's an attenuator and then an amplifier. That's a little bit funny, isn't it? This is probably the disconnect and checkpoint for the output for from the mixer system. And then a rather low frequency go to one of the counter boards.

[00:06:22]And uh yeah, here is another little add-on board or timebase switch. Oh yeah, about the thermal design. As we saw uh on the other um on the top side, the fan is here and then there is a solid wall between the unit where it's open up here. So that means air goes this way around the unit and out here at the back. But there's also a little hole here. And uh that means that air here goes out here, but it also goes to that hole, right? But there's probably also some of the air that goes via this hole that is a lot bigger and this way out.

[00:07:10]So that means air with dust particles goes through this hole with the switch and through this hole with all those switches. So they will be full of dust particles. That is not what you want.

[00:07:24]You always want this compartment to be completely closed so you don't have dusty air through those switches.

[00:07:33]So here from the top the fan look at all the holes here. So air will go through all the circuit boards.

[00:07:44]We can see all the holes here again. And then air will go this way. You see, we have all big holes here and clearly they are closed right here and then out through our mystery boxes.

[00:07:59]I've been trying to look here if I can find the screws to release. Probably those.

[00:08:06]I don't understand what that little screw is doing down there.

[00:08:11]Maybe that is the release. Oh, this is the steering mechanism.

[00:08:16]So, this is just a pin that goes up that will guide you down to the connector. I definitely want to open a few of those mystery boxes.

[00:08:26]Let's inspect some of the plug-in modules here. So, this is one of the counters.

[00:08:33]I think it says decayed. So, that has to be something with the Yeah, we see some counters.

[00:08:45]the 192 and you only see three little capacitors. So this is just a little local signal delay something. But so th those two are actually decoupling for this entire board. Just a two layer board floating flapping around. No ground planes, no nothing fancy. And this is of course because there isn't any crazy rice times in this 1980 technology. We can see the Yeah, see date codes 1980 on most of the chips. There's uh one that was from 1979.

[00:09:27]And uh I've been looking a little bit in this uh unit and I do find a lot of uh date codes or year codes from 1980. that that is so far the highest I can find.

[00:09:39]So I think this pretty much date my unit. So this is the module I believe is my input uh from this uh fascinating mixer system. Right. Look at that. Here we go.

[00:09:52]This is of course this board is using a proper ground plane and oh look at that. Hey, this is has to be the pre-scaler and uh maybe some different band switches band filters and uh yeah it says here 500 ah oh can I show this? Hang on let's look down there at the end it says 500 MHz decade and gate. So that means the IF from all this uh input mixer stuff, it's obviously in uh 500 MHz chunks and then the 500 MHz go through this and then we have a pre-scaler to make it uh probably down to 50 or something like that. But I wanted to show this. Let's see if we can flip this around once again.

[00:10:49]Look at all those local decoupling capacitors and uh those fascinating inductors.

[00:10:57]Isn't that just beautiful?

[00:11:01]I love it.

[00:11:04]I just pulled a few more modules so we can enjoy the design. So this is the time base. We got a little bit of counters. And of course the idea is when you select here on the front u the different timebased settings this will of course activate the different uh timebased uh gauged systems.

[00:11:27]Why is this IC here looking like that? Can you see it looks like it's a little bit uh this is probably not how it's supposed to look.

[00:11:41]It's also cracked.

[00:11:44]H. That is interesting. I think I will monitor this with my thermal camera.

[00:11:51]What else have we got?

[00:11:54]A 10 kHz generator. I don't know exactly what that is doing.

[00:12:02]And uh the next one here is called N computer. So I think this one is the one that multiplies the numbers that we reach from this one because 500 MHz is then divided and we need to um apply different uh if settings depending on how it locks to the incoming uh frequency and so we need to add something and we can see those two IC's here they are running at some high speeds or something like that. We got heat sinks glued to them and the circuit board is a little bit brown. So, I bet they are running at hyper speeds. Something like that. And uh what have we got here?

[00:12:54]Function. I don't know what kind of function that is. It's again just looking like a lot of gates. Yep. Tons of gates.

[00:13:03]And uh yeah, just the regular boring stuff. Ooh, this looks a little bit funny. Okay, here is the 20 MHz input amplifier.

[00:13:20]Yeah, let's let's open this one and have a look.

[00:13:26]Nice with the grounding on the other side of this uh connector.

[00:13:31]Definitely.

[00:13:33]Yeah, doing all that right. And then we got a little bit of gates and uh a little bit of Yeah, I just want to open Oh, nicely shielded. On the other side, too.

[00:13:51]Inside this little shield box, we see this 20 MHz input. There's of course a DC blocking capacitor. And then I bet the signal goes into this IC here, the MC what's 1590G.

[00:14:11]And that is a wideband high gain amplifier. It looks a little bit like an op amp from this distance, but it is a high gain um special amplifier. And uh since we're using this all the way to 20 MHz, there is like 50 to 60 dB gain in this unit. And then it of course clips and then you get a nice square wave output. Well, then you can and then you can count on all that. There a little bit of extra transistors. I don't know exactly what they are doing. I feel this part is probably all you really need to solve this.

[00:14:55]Yeah. So now I want to look at the nice magic boxes and uh then I realize we have all the information here written at the end. They are neatly numbered and also 12. Oops, where's 13? And then you go 14 15 16 17.

[00:15:19]search oscillator local shifter and then a lock if so of course it's jumping in some 500 MHz steps until it finds something then it locks to it and then we will know which one how many of the harmonics we are locked at and then we will add this value to the readout value. I think that is more or less how it works. Again, I am not able to find any information about this one online. So, this is a little bit annoying.

[00:15:56]So, this is inside this uh box that is called NIF.

[00:16:02]It looks quite simple. I think we go in here and we have a little bit of filter amplifier, filter amplifier, filter amplifier, and then another amplifier.

[00:16:12]And this is again one of those MC uh 1590 amplifiers. And another amplifier and a little what is that? Just a little 132. I can't remember exactly what that is doing. [snorts] It looks like we had a little bit of a moisture problem.

[00:16:30]Also, look at this area here. It's not looking super good, is it? I think I want to clean this a little bit. And there's another thing with um this I really want to show. See this? We got some shielded uh this is little um steel. I think this is just steel. And you cut these and look at that. Then we have tiny little metal parts like that. That is loose.

[00:16:58]And the ends like that.

[00:17:02]Oh, you can see they are magnetic.

[00:17:05]And those little tiny parts. Of course, I found a few of them stuck. Uh yeah, here you can even see the little marks.

[00:17:16]So, probably you could find some more if you look real careful. I mean, that is a like a quality issue. You don't want that. So, I'm not super happy about this. Uh, you can Yeah, you can definitely see this is all loose. Oh, yeah. Here, down here. See, there's another little part.

[00:17:38]See? Oops. I got it. They're probably not so nice to walk on either, so I better be sure they go in the trash can.

[00:17:46]Here is another little trick. I do this all the time when I pull stuff apart like this. Of course, I have a lot of pictures and a lot of video, but sometimes it's not super easy to be sure where to put wires back like this because they will fit more or less anywhere. Right? So, I just add the numbers here with a permanent marker now. There is no way I can I can do anything dumb here.

[00:18:17]Very very smart. And there's no copyright on this trick.

[00:18:22]So the next module here is called A15 search oscillator.

[00:18:31]And uh I have actually figured out how this works. I I'm actually really really sure about that.

[00:18:40]We just got some opamps here. Everything comes in and out here. This low frequency more or less dy is what I would expect because we got super low speed op amps here.

[00:18:53]LM201 slow speed op amps right and uh everything here is just op amps.

[00:19:07]So that is what we have here some input and some output op amp stuff. Okay. And this is J1 and J2 of A15. And here comes the explain.

[00:19:21]So here is my 18 GHz input. And this connector here is the A152.

[00:19:34]And here is A151.

[00:19:37]Okay. And it even says here detector output. So this is a DC voltage that goes into one of the op amp systems. So let's say inside this unit here we have a voltage controlled oscillator and a mixer and a lowass filter but also an injector that injects the oscillator divided also by a subharmonic multiplum and of course the measured mixed down signal. That is what we have here. two signals a low and a high frequency coming out of this one. All right. So a DC voltage here is driving the oscillator mixer and everything. Right?

[00:20:25]So the output from this one goes into this. It's called a power divider detector. So here we have one input and we have two outputs, a low frequency range and a high frequency range. And then of course the detector output that goes to the other uh op amp system. So this is what the search um is doing.

[00:20:48]It's changing the voltage here. By changing the voltage it's changing the injector and the oscillator frequency.

[00:20:55]Find a peak and that peak gives a signal here. Now we have the measurement signal out and we have the injector the oscillator because we need to know what what frequency the oscillator is running at. It goes the other way and that is why we have all those extra units here.

[00:21:15]And that is because these boxes here, one needs to figure out what is the actually injected signal, the oscillator, the mixer, what is this running at? And then the other one will count the measured signal. And this way you you can lock and detect and measure uh what you are injecting and mixing with. And then you can of course measure and detect and count the [laughter] input signal. And this way everything here is in lock with our main reference oscillator and will be super accurate.

[00:21:51]Let's do the first power up together.

[00:21:55]So, here is mains. And I would expect it to use a little bit of watts. It's only using 1.4 watts. Is that all? I had the idea um that could be a an oven that will warm up the oscillator and all that, but only 1.4 watts. That is a very very low. So, let's try and uh power up 192 watts.

[00:22:27]And this is uh looking promising. 0.0.

[00:22:32]And if I change this, I will Yes, exactly. We even see a little bit of gate blinky blink here.

[00:22:42]This one is a little bit dodgy.

[00:22:48]So, we have one hertz resolution and I'm using the low input.

[00:22:55]This one. Oh, we have test.

[00:22:58]No lamp. Ah, how nice. I can test all the lamps. There's only one little top LED here that is not working.

[00:23:09]What?

[00:23:11]Okay. So, that is a lamp test. I don't know understand what that is testing.

[00:23:15]reset and then we can go to the low.

[00:23:20]Why is it not resetting after a So we have a um time base problem maybe.

[00:23:27]Oh. Oh, look at that. Now the gate, now it goes fast. Okay, maybe we can do this again. And then Okay, now it seems to be working. Now it's testing the internal uh frequency and then we can go. Okay, that looks very promising. Let's get a an input signal. So here we go. This is uh 1 2 3 4 5 6 hertz at the moment. Also known as 123 kohz.

[00:24:09]And so far that is good.

[00:24:12]So, this one should uh be able to do 20 MHz. So, let's just go all the way to 1 2.34 MGHertz.

[00:24:26]And here you go. This should have been 3 4 and then everything else should have been zero.

[00:24:34]Of course, it just uh I just powered it up, so it's not warming up yet, and it it will take a little bit of time, and there's probably a little adjustment for the time base, but other than that, it seems to be uh working. Yay.

[00:24:49]So, this is a little bit funny. It says 20 Hz to 20 mgz. So, this is 19 megahertz.

[00:24:58]The fun thing is when I go to 20, it's not working anymore. So, I think 20 is Oh. Oh, we have a Oh, yo. Yoy, look at that. We have a dodgy connector here.

[00:25:18]Is that really some something else? You just saw it.

[00:25:28]What did I touch?

[00:25:34]This is all magic. I have to Well, I need to figure this out.

[00:25:40]There is something that is weird. And if I go back to 19 MHz, it is working again. What a weird thing we have here.

[00:25:52]And what have we here? So this is a 100 MHz input and it goes into lock. So that means it found my input signal and it locked on it and it's uh counting my 100 MHz. And if I remove my signal, see the detector goes off.

[00:26:13]So there's a this is of course the normal range of lock. You can also select wide.

[00:26:22]How's that working? I don't know what kind of it still detects this pretty much.

[00:26:33]So if this one can do Okay, let's try 20 MHz and see if 20 megahertz.

[00:26:42]So this system also works at 20. What if it works at 19?

[00:26:47]Aha. Can we go even further? 18.

[00:26:51]Let's go all the way 14. Okay. So, there's a lot of headroom on this.

[00:26:58]See, even 10 MHz it works.

[00:27:01]What if we go to 5 MHz? Ah, see then there is something that is not working.

[00:27:10]So, this is 8 MHz and then it reads 9.

[00:27:12]Okay. Anyway, 10 MHz works. All right.

[00:27:15]Right. So, we should of course follow the ranges. So, that will be 20 MHz. Let's just go to 500 MHz.

[00:27:26]Hello. Yeah, of course it works.

[00:27:31]Oh, and I even see this little top digit here is actually working. I think it's just because there is some metal grip here on the on the front that is exactly where it is um in the way. Hang on.

[00:27:45]Yeah. See, this metal shield is in the way from this angle.

[00:27:59]Wow. So, it really works. I'm super super happy. So, I think this concludes this uh unit. I think I'll call this the end of this video. So, thank you very much for watching. I hope to see you soon again. Bye-bye.