Like seeing an old friend--when this machine last wobbulated, I was beginning a basic electricity course at Lowry AFB en route to becoming an aircraft weapons mechanic. Much later, I was to learn that wobbulated signals centered on 4300 MHz are the basis for commercial aircraft radio altimeters. Somewhere in between, I came to recognize the quarter-turn fasteners on the top of the box as authentic Dzus fasteners, the original quick-release fasteners used on the DC-3. I still have a screwdriver I cut down in 1965 to fit under DC-3 cowl flaps and unlock Dzus fasteners in the engine accessory cowling. Next, I will watch your video on VTVM restoration and learn what I might need before I dig my old Heathkit IM-28 out of the closet. Thanks for the motivation.
+Mr Carlson's Lab Let's not forget about soldiers that actually had to carry this boat anchor in the field. Thing probably weights more than a box of grenades, and with box of grenades you can at least defend yourself! ;) Unless you consider throwing this from the roof to the enemy's head as alternative application.
Hi there Mr Carlsson! Will there be a restoration video of this unit? Because I am really looking forward to it. Aldo, I love your videos, keep 'em coming! 😊👍
You might be surprised and find all the caps are still good. I have a lot of 40-60's military test equipment and radios and don't think I have ever changed one yet. I'm always amazed at the quality and durability of milspec capacitors. Many are hermetically sealed. Might be worth unhooking them and testing them for leakage. Thats what I do and haven't changed one yet. Will be nice to see this back up and running. I love old military gear. Mike
I repair Ampeg Tube Amplifiers and they too paste a copy of the correct Rev schematic inside the cover. I agree 5 Stars all the way !!! Very nice piece of gear you've shown us Paul - thank you.
Looks like front-line DEW equipment... I'd be curious to know where and how you acquired it. Even more so, what the Government paid for it (adjusted to today's "dollars") and what cost in fractions of pennies you paid when you acquired it! Fair Radio Sales (in Lima, Ohio) "still in business today since 1947, has a Web site and NO DOUBT has any of the more esoteric parts you may need to do the restoration, outside of all of those capacitors!
Hi again Mr. Carlson. Would you mind sharing an high resolution image of the schematic for your wobbulator with a link for your subscribers as a reference for those who may also be restoring this type of equipment or just have a general interest in studying electronics? I had to look around quite a bit to find any documentation for the wobbulator online and I think it would be helpful if we subscribers could find it on your channel. Thanks for the great videos and keep up the good work!
+uomo d'onore Hi, I snapped a few pix of the wobbulator schematic, but haven't even uploaded them yet. I will consider a file sharing account in the future.
Another awesome video, and an extremely interesting piece of history. I think your lab, btw, probably has more broadcasting, processing and analyzing power than most countries entire intelligence departments. Well done!
That thing looked like it would have survived a nuclear blast and I bet that really was one of the design criteria. Truly amazing the craftsmen ship that went into that unit. I wonder what it actually cost the government to make it back in the 1950s.
Hello Mr. Carlson. I found another schematic for the Dubrow ts-452 online. This one includes a diagram of a filtering network on the mains input line that was not included on the schematic that is on the bottom cover of your unit. It will be interesting to see if there is a line input filter on your unit when you do your restoration. If there isn't, I wonder why it would not be included on some units. I wonder what your thoughts would be on this. Oh, and here's a link to the alternative schematic I found online. richardsears.files.wordpress.com/2011/12/dubrow-ts-452-rf-sweep-generator-oscilloscope-schematic.jpg
+uomo d'onore Thanks for your input. I have talked to Richard in the past, when I got the wobbulator, His site completely slipped my mind, I'm pretty sure I even left a comment in there somewhere as well.
I would re-stuff those caps, to keep something like this as close to original as possible. Hell, even re-stuff all the caps may be a good idea :) Nice video Paul. I love to see how this older tech was made a the sheer craftsmanship that has been put into such a unit!
Ha ha ha, he said Wobbulator... Hu hu, hu hu... The way the military built things was just astounding! I'll bet the reason they used a mechanical sweep was for pure reliability in the field. Awesome find!
The best I assume the unit was built by either the USA or Canada right it was very interesting to say the least pretty well made to again say the least thank you paul
Paul i can't help but be impressed with editing and even manner approach to these educational videos do you ever have out takes or bloopers just wandering I think with your approach to repairs has something for everone and important stuff you go over more than once in the videos nice complete!!
brilliant bit of old kit ...over here in the UK lots of old ex army surplus are always turning up on ebay and at second hand stores and junk shops ...sadly loads are scrapped as the average person to come across them just think there scrap .....keep up your good work ☺
Such a well built, sturdy apparatus. Just goes to show the difference between long lasting, military engineering and 'built-in obsolescence' consumer electronics!
Wow, very interesting teardown and explanation of this unit Paul. This time I will say it looks like it was built "FOR" a tank.. I have a big bag of those plug in style NOS capacitors. As we know as old as they are they are only conversation pieces. That manual sweep circuit is interesting. Wonder how they are keeping noise to a minimum there. Will enjoy seeing you get this back up to speck. Thanks for another great tech tip Paul. Thumbs up!
Now that the labs are being moved, I will come across it again. It's behind about 10000 pounds of equipment in storage. It will have it's day on the bench :^)
That schematic looks like it was drawn by the same guy who drew up Leo Fender's schematics..... Very organized, logical, and fairly easy to follow. Those were the days......
This looks like a Jack Davis or, more like Wallace Wood 1954 mad magazine cartoon. That observation aside, this is another of Mr Carlson's great example of the timeless quality equipment this country built..at one time.....
18:12 They used to do that with all JAN spec gear; didn't matter whether it was calibration kit like this or a jukebox at the officers club. You're actually giving them kudos for simply following SOP?
We used a similar one to tune vehicle tracking system front-end receiver filters back in 1988 in South Africa when they were using a 'fox hunt' triangulation system (4 antennas on a square ground-plane on police squad cars) that would rebroadcast two local beacons on the tracking frequency that would allow for a LORAN by proxy location system that was good to a few hundred meters and did not need expensive and easily shielded GPS of the day. The systems were hidden into vehicle upholstery and seats and had no connection besides a wire to charge the small backup cell. I think they were activated from the beacon signals by the tracking company and the police could home in on them quickly.
I just found soviet made similar device in recycling place near me. but it is 65 euros in "turn on" condition, so not decided if I want it so much :) Model x1-50 much smaller and who knows where it is made with famous dubious soviet tech :)
And here I thought dynamotors were a clever way to bump DC to high voltage DC! That motorized sweep generator system is something I have never heard of before, that's really cool, almost going back to electro mechanical television!
The BBC Radiophonic Workshop used multiple instances of these back in the 60s and 70s as audio sources for sound effects and theme music for TV programs.
Funny how a cheep 50 dollar VNA can replace this now, and less inacurate as a thousand dollar spectrum anlializer this one, does an good job. Used for bandpass filters antenna resonance and alot more. Heathkit sweep generator used a toroid with dc winding to sweep, a cool idea at the time, varicaps and digital synths now do the job. things keep changing over time. Not A basar piece of equipment as you said but important at the time for alignment !!!
As someone who knows absolutely nothing about electronics but finds these videos about old analogue equipment fascinating to watch I have a quick question. Are these devices resistant to EMP as I think i read somewhere before. You might end up being the only person in North America with a fully functional lab when Kim Jong Un launches his nukes.
Is a piece of equipment like that still useful for today? Is it worth fixing and calibrating? I love his videos of old equipment and restoring them. He reminds me of my dad when he would fix his stuff.
When I worked outside plant for the phone company as a young man, the saying then was that if the test meter wasn't heavy already, then they'd put it in a heavy box to make up for it.
It's funny, I have used a wobbulator, but it was a completely different thing. We used it to calibrate the sensors on rotating equipment that measured vibration. It had a rotating disk that was flat but eccentric. Imagine a record player with a spacer under one side. As the record turns you get an upwards movement and hen a downwards movement. We would measure this with a dial indicator, and we could calibrate our probes to this movement. Literately measuring how much it wobbled....
LOL... I started saying I need to use the wobbulator when I wanted to borrow the Aeroflex. Very fun! We got several Wobbulators but that is the only one that we own that is P25 certified by the feds.
Ohooo ohoooo teacher teacher I know what a Wobbulator is.... it is an early sweep signal generators (without a scope). I rebuilt some early ones... I have long gone to digital old HP... far better.
"Simple stuff" but at that time it was almost just the army who coul afford to have that gear in their "arsenal". I'm sure you are going to fix that gear and give it 100 more years of life!!
That is a neat piece of test gear, oh the wobbulator that reminds me of my very first sweep generator, it was a very old Hickok and it used a regular speaker without the cone, it had a metal plate and was something like a vibrating capacitor, depending on how strong the AC voltage was applied to the "voice coil" determined the sweep width. It just used a low 60 cps voltage on the "voice coil" BTW, I never liked saying hertz, on these old things I like the good old CPS...LOL
Most oscilloscopes have a swept horizontal time base, so how would this differ from a regular oscilloscope? I have been around old test equipment for a while now, and this the first time I have seen or heard of such a unit. While I have seen external sweep generators before, I never had a need to use one. The mechanical driven sweep circuit sounds similar to the electronic version of a Leslie speaker in which they used a motor to turn the plates of a continuous rotating variable capacitor and this is what caused the sound to shift from speaker to speaker, creating a stereo rotating speaker effect.
Paul, Believe it or not, I've actually heard of a Wobbulator...even seen one if I'm not mistaken. It was many years ago during my GI days. Hard to remember that far back. LOL It'll be neat to see it once again functional. Good luck with it, my friend. Regards, John
Paul, most of the Capacitors are true OIL FILLED and almost certainly fine. These almost never fail unless physically damaged and leaking. Caution, likely PBC oil. But if not leaking will be fine.Remember Selenium Rectifiers have a pretty high internal resistance and solid state replacements will need a series resistor to maintain original voltage spec. Again, test and likely OK.Uncle Sam built them to last. Expense was not an issue.
+The Radio Mechanic Hi. Unfortunately, 4 of the electrolytic's are beyond bad, and 5 of the oil filled blocks are faulty as well (electrically leaky) l I haven't finished testing all of them... And will do a video on this unit at a future date. Already it's looking like a in-depth restoration.... Motor doesn't turn either :^/ I would tend to agree about the dependability (electrolytic caps only) with a piece of test gear like the older Tek scopes, but I find this older Uncle Sam stuff to have faulty parts all the time. If you are restoring older devices with these oil filled cans "square blocks" in them, I strongly suggest you change them, or the unit being restored will ultimately be unreliable in the future. I have found many faulty oil filled blocks (capacitors) in: Collins gear, Hammarlund, RCA receivers, Singer metrics spectrum analyzers, The Panoramic Radio Corp, Lavoie test gear, and so on. I have a small drum full of these faulty units, that I save for re-stuffing. Thanks for your comment!
+Mr Carlson's Lab: Paul, a great introduction to and tour of this piece of gear. I'm curious - how and where did you find it? One of many challenges for you may be having to custom-fabricate the carbon brushes for the motor - I would not be surprised if you find that one or both of them is missing or completely worn out. Another issue related to the motor might be, if not the brushes, a burned-out winding on the motor's armature. I hope it's nothing more than a stuck or worn-out brush. Also, you'll have to make sure the commutator on the motor's armature is in good shape. Knowing you, you'll tackle all these challenges using your superb analytical skills and technical know-how! It's always a delightful experience to watch your videos. They're all A-plus!
Thanks for the kind comment Jos! I found the unit about a year ago on "CL," locally. It has been sitting in my storage until now. I sure hope the motor is in good condition, if not, that would add a lot of time to the resto. I have filed many a carbon brush...LOL. I find that Dremel replacement brushes are a good size to start with for many small motors.
Looks like front-line DEW equipment... I'd be curious to know where and how you acquired it. Even more so, what the Government paid for it (adjusted to today's "dollars") and what cost in fractions of pennies you paid when you acquired it! Fair Radio Sales (in Lima, Ohio) "still in business today since 1947, has a Web site and NO DOUBT has any of the more esoteric parts you may need to do the restoration, outside of all of those capacitors!
A Radio Collector Mate gave me a 1970 Nordmende Wobbulator for free. All the Tubes were pulled and for now it's only smoking, when I got space again to work on it I will try to restore it... Thank's for the Explaination!
Very nice wobbulator. This is the first one I see with a motorized capacitor. That is very nice. General radio sold motordrives for this purpose to use an unit oscillator as a sweep generator. I once made a spectrum analyser from a receiver this way (just as an experiment, not permanent, I could be a nice video if you have the kit to make such a set up) I have an army version that is from the same area I think, see: www.pa4tim.nl/?p=520 (I am an analyser junky, I have a whole family of network analysers like VNA, SNA, wobbulator, SA+TG and some DIY ) Does you wobbulator needs an external diode detector or is it build in ? Is it tuned ? The biggest difference between a wobbulator and a SNA /SA+TG or VNA is the detection. A wobbulator detector is often wideband, the detector responds to the highest magnitude and that can be a harmonic or mix product. That can be handy in some cases. They often came with a cool type of adapter you clipped on a tube to inject the signal capacitive into the tube. All other type of network analysers had a tuned receiver. So they only respond to the incident signal. The term network analysis is a bit confusing, I'm not talking computer networks, that is a whole different game. An anecdote, I repair test an calibration gear for a living. Someone phoned me asked me to fix a network analyser. Some red lights should have flashed when he did not understood the question about the bandwidth. When it arrived it turned out to be a computer network analyser. (fixed it anyhow) If someone wants to know more about how to use an "analyser" cq network analysis I wrote several tutorials for the beginning network analyse aficionado (and HAMs who want to know more about that to better understand their antenna analysers) because there is very little information for beginners about this subject. www.pa4tim.nl/?cat=26 Fred, pa4tim
+pa4tim Hi Fred, Great write up! I have an analyzer collecting "issue" myself LOL! Thanks for the link, I will check it out. I haven't looked at the probe in the lid yet. I believe it could have the diode detection in it. When I do the restoration, I will have a complete explanation, along with an example sweep.
Great find Mr Carlson. I bet you smiled when you took off the bottom panel. There can't be too many manuals for that unit around anymore. I have an old 50's military FM transceiver (uses 1U4's etc). Was happy to find a schematic printed on a silk material folded away inside. Looking forward to another one of your excellent restorations !
+Todd Anonymous You Bet! That was a great surprise! One day I will build a portable radio project with those 1 Volt filament tubes. I have quite a few.
Wow, that test equipment is in pristine condition. Understood that the caps will need to be replaced, but its so clean, you may want to just plug it in right now! Once you get it going, I will bring by my two BC 1004's for alignment! We both will get a good workout from lugging all those boat anchors
You should NOT hand it over to terrorists groups, because they may can use it as an atom bomb, hahaha just kidding, but it's incredible how such machine was built and used back in the day.
I do so much love gear of that era that DOESN'T have that ONE sticker - 'This unit has no user serviceable parts, please refer it to an authorized dealer for repair' ! Oh, damn! that bay at 10 O'clock makes me all sweaty and bothered!
What advantage is the motor for the sweep generator? Why wouldn't they just do it with an electronic oscillator? Very good explanations. I'm addicted to thermionic emissions. Much of my Ham station is tube gear as well. You are much younger than me albeit much more educated. Why did you take an interest in tube gear? Thanks very much for the video's. I was never able to finish my EE. Your video's help fill in the gaps.
I think the problem is the technology to do the sweep back then was much more limited. Keep in mind that you need a linear relationship between the frequency and the sweep voltage, or else your frequency scale on the scope is going to look strange. You also need to sweep a very wide frequency range.
Carl picks up a Collins R390A for a restoration process, alignment and replacement of components ... It would be very interesting to see his talent when dealing with a radio receiver such. A radio show receiver in the hands of a true artist of electronics.
Newer technologies may have more bells and whistles than the older gear, but the quality and engineering excellence of older technology is amazing! They really built things to last back in the day. Good luck trying to find that now in our current age of planned obsolesce.
I much prefer watching the trouble shooting skills being shared. This one lost my interest right off the bat. It seems like you might be starting to struggle for good content. Put a radio on the bench or an amplifier and keep showing how your powerful mind goes at walking through how you attack the problem. When you do that it is magical.
+Kevin Gray Hi Kevin, I do appreciate your input. I have been working on a video for the last 4 months or so, between normal work. That is an in-depth video on a device that has been up and down, on and off the bench, what seems a 100 times now. I'm extremely busy, and even fitting in the TTT series has caused a few all nighters. I think spotting my red eye's in the video content is apparent...LOL! Once this "on going" video is done, I will be back to regular troubleshooting video's, and will go back and fourth between them in the TTT series as time permits. If I were to just do video's full time, I would be able to put a lot more troubleshooting and repair video's up. I think the ratio is about 1 video in 20 repairs "or so" right now. Taking a video while I work, with ongoing explanation, camera set up time, and mic set up time, makes the repair time about 8 to 10 times the normal repair speed, so I have to choose wisely. "I'm not in any way struggling for content Kevin." I have so much to share, I haven't even begun yet! It's all about making the time to video. If I was to make You Tube a full time thing, it would have to pay the bills. Please be patient, I'm doing the best I can, to share what I know.
18:10 It's a military field unit and a highly specialized mission-critical piece of equipment; of course it's going to have the schematic on the bottom chassis plate. A field tech can't be expected to carry around schematics for every piece of gear he could possibly encounter and DARPAnet didn't exist yet. This wasn't uncommon in civilian gear either. I've seen a Motorola jukebox schematic on a chassis plate like that. (It was just the amplifier chassis, but I'm sure the disk changer mechanism had its schematic in the case as well.)
I know this is a few years back Paul, but what a piece of kit!.You can see it was purpose designed and built especially for the job it did.Which is slightly different to the Marconi R1155 receiver that I am trying hard to fully restore.That was needed quickly, but hey it did an excellent job.Which is a tribute to the electronic guys who designed it.Just absolutely love this old equipment.If only I had purchased more of it in the early days, when it could hardly be given away.I could sell it off now and be better off than I am now.Brilliant Channel.Going to increase my Patrion subs very soon.Thanks for the excellent channel Paul.And the knowledge that you impart.It is appreciated by so many of us.
