Tek 454A vs HP 45600B
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- Опубліковано 15 жов 2024
- Vintage AM radio IF signal viewed on a 70s analog scope vs a 90s digital scope. Which do you prefer?
Also, new feet have arrived for the Tek 454 - some 3-d printed. How do they compare to the originals?
So glad I trained on analogue scopes
That's why I bought myself a digital and an analog scopes. Great video!
I have an HP 54600B on my own, cool scope, really like it! As far as I know HP designed this scope to be "portable", which is probably the reason for it's light weight and small size. The maximum input voltage for this scope is actually 400V, but it can't display anything greater than 5V/div. By using an 10:1 probe you can surely achieve 50V/div. Your "stack of needles" waveform can be improved by disengaging vectors in the display menu. This will make the scope stop drawing connection lines between measurement points. In my opinion this leads to a way more "analog looking" trace, which I prefer for AM. By using the HF trigger rejection, the scope can even trigger on the envelope.
Thank you for the tips. I will give them a try in the very near future.
There are a few 'scopes floating around here: a Uni-T scopemeter (great for looking at the power line, inverters, variable frequency drives, etc.), Craftsman Scopemeter, an 1970s RCA "TV service" grade analog 'scope that one of my brothers was kind enough to rescue out of the trash for me, and one of these HP 'scopes. At some point I'd like to find a decent Tek 465 and obtain a modern digital 'scope from the likes of Rigol or similar.
The RCA is one like I'd like to get going at some point. When my brother rescued it from a dumpster, he said it displayed a trace. All it did for me was make a soft ticking sound, but I'll admit I lost my nerve before it really had a proper chance to warm up, and I unplugged it. It's nothing stellar (*maybe* 50 MHz bandwidth on a really good day?) but could certainly still be useful and is in good physical condition. I should probably try it again with a series light bulb...
Can't go wrong with a 465. It is technically repairable just like this 454. Just be ready for several 100 pages of schematics, parts layout diagrams and parts lists. I find it overwhelming but also hard to fault a company for being thorough. I'm curious about that RCA. Their scopes don't turn up often but they are well made.
Decent comparison you did there, you know the pros and cons of each technology. The latest Tektronix full color digital scopes are wonderful, and worth what they charge for them. But they can be costly for a hobbyist.
I'm still using my 1965 Tek 422 for most things, because it's so easy, and use the 1985 Tek 2465 when I do high frequency work (I think it's 300MHz over the 4 channels). The 422 has never failed nor gone out of calibration (it was last cal'd in 1976). Both are in mint condition. I bought the 422 in 1976, and the 2465 in 1996, fully cal'd from Holtek in SValley.
Thank's very much Bob!
There are also some hybrid scopes. In analog mode they show waveforms completely in analog but simultaneously have digital overlays like measurement cursors. In digital mode they're just a basic early digital scope. AFAIK modern digital scopes are much more useful than old ones because they usually have deep sample buffers letting you zoom into one-shot captures.
And it's bugging me a bit that your Tek has some of its controls set to 'uncalibrated'. This is the red fine control knob inside of the range switches. These need to be turned to their detents in order for each division to actually mean what the control is set to.
The calibration is way off anyway. Also those detents don't register very well when in the cal position. Likely dirty controls.
most stuff I have printed, I design myself, and I use hard ABS since I can glue it if needed
Thanks for the video, lots of good information. I have a tec. 453 that appears very similar.
18:14 You don't have to measure between the peaks of the signal, that's rather hard to get right,
if you measure at the Zero crossing point, it's much easier to put the cursor right at the spot as it's not jumping all over the place.
I have an old Tek 2225 scope, and it's a great scope for some use cases, not all.
Sir you got a new subscriber
Very helpful video. Thanks
That HP is sweet vintage. Works pretty good for most of our electronic hobbyist applications. The Tektronix scope
still is a work in progress. Your 3D printed feet are going to fail eventually because you need some extra strength
inside the hole to provide proper support. Maybe you could drill a correctly sized hole and add a threaded rod that goes
from inside the case to the tip, although you would need a hex shaped hole to lock it in place ( for a nut) there. Hmm.
I prefer the analog scope for most measurements. Although that digital one has a hidden video game built in. (go to Print/Utility and try pushing some of the unused soft buttons at the same time, mine has an almost arcade exact port of Centipede)
Try video signals on the digital HP. If it's almost perfectly adjusted, after about 10 minutes I can tell you I'm looking at a video signal. On the analog scope, even if it's way out of whack, I can tell you it's a video signal after a second and when it's adjusted, I can even see if the game board I'm fixing is running and I can even identify some games.
But when it comes to fixing, it's the other way round. I have an easier time fixing the digital scope than the analog one.
One cool thing about video waveforms on the digital HP though is - if it knows it's a video signal, you can zoom into the horizontal domain and it can tell you which scan line you're on and will only show you that line for every frame received! So both machines have advantages and disadvantages.
Hehe - and when it comes to boot times - I have a Tektronix 535 from 1964. It takes a minute to "boot" (there's a time delay switch to make sure the tubes have all warmed up before kicking on).
I've tried many times, but never been able to get that hidden game to come up. I have the same experience with video and the HP. If it can recognize the signal, the frame modes are handy, otherwise it's a mess.
I also have an old Tek 531 tucked away in storage. I'll get it up on the bench for some fun one of these days.
I have a Fluke PM3082 100MHz scope which has auto-adjust and is analogue but with digital overlay for values on screen, such as amplitude, frequency etc..
I have an HP1710B for analog stuff and a Tek TDS380 for digital stuff!
I'd send those 3-d printed feet back and request he print a version that will accomodate the original metal part.
Oh it was stated in the listing that the metal inserts would not fit. No deception there. I had low expectations when I bought them I mainly did it for my viewers benefit in case they're considering 3d printed parts.
I myself prefer an analog scope for troubleshooting TV and radios, mainly because that's what I'm used to using. I have used a late 90's HP digital, which I hated but was forced to use anyway. The company I worked for then decided to replace ALL their analog and combo analog/digital scopes with HP, regardless what their techs liked or wanted. Sounds to me like they caved in to a sales pitch, and had no idea what they were buying. Those HP scopes were garbage, with dim displays, and poor quality waveforms. If you tried to expand the display to see the higher frequency components of a complex signal, all you got was a string of dots with empty spaces in between. When you have to turn the workbench lights off to see the display on a NEW scope, is absolutely ridiculous.
If you're feeling adventurous, find the way to remove that rear frame, and have that bad corner restored, with welding and tapping a new threaded hole. As for those four rear feet, you could remake them using the metal insert and the 3-D things as models, or find a parts scope that has what you need.
Funny you should bring this up. While replacing the line cord I had to remove the rear frame. It's only haled in by a few screws and would be easy to replace. I'll put out the word that I'm looking for one.
Make low-ball offer on a eBay parts scope to get what you need to restore your scope.
Cut the threads off of those new feet, counter sink the hole on top, insert the metal base on bottom and run bolt through and flush with the counter sink.
So...I'm not sure if you're aware but your particular series of HP scopes, and most early digital scopes in general are generally regarded as being junk...The main reason being abysmal sampling rates, the second being very small capture memory.
I know it boasts a 100Mhz bandwidth but the effective bandwidth is closer to 5Mhz. How can that be? The sampling rate on the 54600 is only 20 million samples per second. The Nyquist sampling theorem states that you need at least 2x the sampling rate of the bandwidth to properly sample an analog signal, ideally 4x or more. This means 20/4 = 5Mhz. Then what is the 100Mhz referring to? For repetitive signals, that is, a signal with no glitches and a fixed pattern can be sampled over many periods to give the illusion of having a much higher bandwidth. A true 100Mhz scope will have a sampling rate of 500Ms/s or greater.
If you do a spend a lot of time looking at waveforms, especially single-shot captures where high sampling rate really matters, I'd highly recommend moving up to something a bit more modern.
I'm aware of it's limitations. I primarily restore vintage radios and TVs as a hobby. I rarely use a scope and when I do I'm typically looking at repetitive waveforms less that 20kHz. TV sync signals mostly and some audio.
@@bandersentv Apologies if that came off as rude, I get worked up by deceptive marketing. All the literature and specs state 100Mhz bandwidth which the majority of people would assume means they have a 100Mhz bandwidth scope. It's not until you get to "Single shot bandwidth" that it actually states 2Mhz. It's easy for someone to get caught off guard thinking they have something they do not. But at least you have the Tek to help fill the gap if you ever need it.
my Tektronix 7934 is a damn monster next to those, 50.0 pounds with modules, and Will tell voltage which it does,, & freq ( with the right module) , which i do not have :(
When we went to digital oscilloscopes at work in the late '80s I was appalled by the poor resolution and even worse, the poor sampling rate of the early models. Glitches that were easily seen with an analog 'scope would not be detected at all or even show on the screen. It took me a while to grasp the concept but anything that happens between sampling points is ignored! Stuff has gotten way better, including far more sampling points but I still don't like or trust the digital ones.
Totally how I also felt, even into the early 2000s people were so proud of their crappy digital scopes.
I still prefer my Tek analogs (422, 2465) as well, though the newest Tek digitals are full colour, full measurement, auto-everything, and mimic analog displays so well, you can't even tell the difference. There are still the usual disadvantages on both sides. I'm glad I have the analogs.
Your disapproval of the 3d prints is strange. That they are not as strong has nothing to do with 3d printing, its a materials limitation, one the original designers got around by using machined steel parts. That solution was viable due to the scope's high price tag-would you have paid enough for someone to remake that part on a lathe?
If you wanted to, you could drill out the inner hole on those prints and glue in some threaded tube with nuts to take the lateral force.
My issue is that the part breaks along the seam between layers. It is not fused together solidly. The originals are rubber. I would pay someone to mold and cast them.
While I have hundreds if not thousands of hours with the Teks and HP scopes, I think your money is better spent on a modern DSO. Nostalgia aside, you can get far more capability for a few hundred bucks. But it does depend on what you're doing. And measurements? No contest. To be fair, I love the old stuff, but just the waveform storage and capture of even single events makes the decision simple.
I totally agree in general. If I was starting out in the hobby and working on all sorts of project, absolutely I would get a brand new DSO.
They're more than fine for my needs though. I mostly work on vintage TVs where I'm looking at 60Hz vertical and 17.75kHz horizontal signals. I sometimes use an old 10 MHz scope :)
@@bandersentv I have both a modest analog scope and a 3 channel hantek 1.5 gHz DSO.
For industrial automation, the DSO is worth it's weight in gold. You can trigger on a fault and then look back in time to see what caused it. Nothing else will do that.
that is, however, a pretty old digital scope
Digital=Virtual=not real=subject to change=not a Vote.
( this also applies to the intelligence you are trying to view on your carrier.)