There was a labor shortage of iron workers my freshman year in high school. My father was short 2 or 3 iron workers. So day after the last day of school. Pack my bags and one hour later I was going down to LA (other side of Riverside) 5 hour drive to put up metal buildings for summer.
I have some VTVMs of the Vintage era, bought for peanuts or given as gifts...
CTR HR-160 and HR-240 - Germany :
Heathkit model V-6 - USA
PACO V-70 - USA
TonFrequenz / ULTRON - Germany :
All of them are accurately calibrated, in fine working condition... They are not ridiculous at all when compared to the modern ones I also have :
But the modern of course can be more precise and easier to use...
T
CTR HR-160 and HR-240 - Germany :
Heathkit model V-6 - USA
PACO V-70 - USA
TonFrequenz / ULTRON - Germany :
All of them are accurately calibrated, in fine working condition... They are not ridiculous at all when compared to the modern ones I also have :
But the modern of course can be more precise and easier to use...
T
Hi tubelectron,
New ones might be accurate. Your 87s will be up to a certain frequency on AC. The others you have will not be. They may also not hold calibration over time or at higher voltages over a short time.
Also, your meter movement types are average responding and will agree with early service documentation, the digital meters absolutely will not.
I like your collection. I also collected some VTVMs and other early instruments.
New ones might be accurate. Your 87s will be up to a certain frequency on AC. The others you have will not be. They may also not hold calibration over time or at higher voltages over a short time.
Also, your meter movement types are average responding and will agree with early service documentation, the digital meters absolutely will not.
I like your collection. I also collected some VTVMs and other early instruments.
The VTVM looks greatI have some VTVMs of the Vintage era, bought for peanuts or given as gifts...
CTR HR-160 and HR-240 - Germany :
View attachment 1212801
Heathkit model V-6 - USA
View attachment 1212802
PACO V-70 - USA
View attachment 1212804
TonFrequenz / ULTRON - Germany :
View attachment 1212805
All of them are accurately calibrated, in fine working condition... They are not ridiculous at all when compared to the modern ones I also have :
But the modern of course can be more precise and easier to use...
T
They all have there place.
I Simpson 260 and FLUKE .
The VTVM is great for adjusting and take very little
the from circuit.
The DMM also has a refresh rate too makes a pain in adjustment
Dave
Quasar cameout that year and I could see hand writing on TV techs.
Yes my father did me favor.
It was job where had very few tools like welder , hand saw, wrenches the list goes on. The others was also most green as I was.
It was only job I used a propane cutting torch for welding use a coat hanger for rod. No else on crew could torch weld.
The year before my father on job lost $50,000. So help him to I did not take any money. All I was going to do is buy electronics and RC equipment.
The techs in the 1950's and 1960's would turn the VTVM to heat up for more accurate readings about 1/2 hour and some would leave on 24 hours a day.I have some VTVMs of the Vintage era, bought for peanuts or given as gifts...
CTR HR-160 and HR-240 - Germany :
View attachment 1212801
Heathkit model V-6 - USA
View attachment 1212802
PACO V-70 - USA
View attachment 1212804
TonFrequenz / ULTRON - Germany :
View attachment 1212805
All of them are accurately calibrated, in fine working condition... They are not ridiculous at all when compared to the modern ones I also have :
But the modern of course can be more precise and easier to use...
T
I have never own a real VTVM.
The VTVM I have is a FET using LF353 chip and is balanced bridge. I just turn on and start using.
Yes,
One of the most interesting of my little bunch of VTVM is the TonFrequenz/ULTRON LMV-85 since it is an AC mV/V meter with a 1MHz bandpass. Moreover, when compared to my SIGLENT SDM-3045X, it offers very consistent measurement results...
The others are from a more anecdotical use, the CTR ranking first, the PACO and Heathkit second in precision / repeatability, because they have more suffered in their past years...
Similarly, my old CRC French Navy oscilloscope - full tube from 1964, with a 1.5MHz bandwidth - is able to track flaws that are unnoticed by my digital SIGLENT SDS-1202X-F scope. Moreover, it is fitted with a 50V/div attenuator...
T
One of the most interesting of my little bunch of VTVM is the TonFrequenz/ULTRON LMV-85 since it is an AC mV/V meter with a 1MHz bandpass. Moreover, when compared to my SIGLENT SDM-3045X, it offers very consistent measurement results...
The others are from a more anecdotical use, the CTR ranking first, the PACO and Heathkit second in precision / repeatability, because they have more suffered in their past years...
Similarly, my old CRC French Navy oscilloscope - full tube from 1964, with a 1.5MHz bandwidth - is able to track flaws that are unnoticed by my digital SIGLENT SDS-1202X-F scope. Moreover, it is fitted with a 50V/div attenuator...
T
Oh, it's just a service single-beam oscilloscope, but it is so well-built and over-designed that it is foolproof. I bought it NOS with its complete user/service documentation.
Cathode-ray tube post-acceleration is 1.5kV IIRC, giving a super-fine trace on the screen. The 50V/div. attenuator allow to see 400V peak-to-peak on the screen, which is very useful for studying tube circuits with their high voltage and gain levels... Don't ask this to a modern scope, unless you have a convenient probe !
Simple to operate and reliable, he is my old faithfull... Now he is part-time retired (or saved) thanks to the SIGLENT SDS-1202X-F double trace digital scope.
The brand is CRC, aka Constructions Radioélectriques du Centre, which was located in Saint-Etienne (OK, centre-south in France). Now this company is called SCHLUMBERGER, and specialized in measurement systems and avionics, still for the Army and Industry.
T
I like the clean waveforms of a CRT compared to the blurred waveforms scopes of today.
But they provide enormous amount of information.
Also, I do not trust the life of a LCD screen, may be 5 or 6 years, compared to 20-30 years of CRT.
With CRT, you still can adjust the filament voltage internally when the display worsens.
Regards.
The oscilloscope I is 1965 Eico 435 works great.
The new scopes have lots of bells and wishlists after that not must different. If need copy of the pattern I use my cellphone. I also the first owner.
Dave
I try a pc sound card oscilloscope and did not give detail my Eico 435. My oscilloscope is almost new I did not use for almost 50 years. I think a got in 1965
Dave
Most quality test equipment calibration procedures call out 3* important things to do before calibrating:
Required* warm up time
Required* Calibration Lab temperature range, and the Actual* temperature during the calibration (that is written down on the calibration sheet report that goes back with the newly calibrated instrument).
Sometimes the humidity during calibration is also written down.
There are lots of other things that are written down in a formal report.
The actual test equipment used to do the calibration, serial numbers, etc.
I am just reminding those of you who are as old as I am, how extensive and formal a quality calibration is.
Required* warm up time
Required* Calibration Lab temperature range, and the Actual* temperature during the calibration (that is written down on the calibration sheet report that goes back with the newly calibrated instrument).
Sometimes the humidity during calibration is also written down.
There are lots of other things that are written down in a formal report.
The actual test equipment used to do the calibration, serial numbers, etc.
I am just reminding those of you who are as old as I am, how extensive and formal a quality calibration is.
tubelectron,
Wonderful scope!
The two Red knobs are Not Foolproof.
Fools turn them out of the click stop/or Cal setting, and think all the readings are still calibrated.
Most of the scopes on my US Naval destroyer were not as good as your scope.
Only the HP 5MHz scope was better, but it was dedicated to a specific system maintenence, and could not be used elsewhere.
Wonderful scope!
The two Red knobs are Not Foolproof.
Fools turn them out of the click stop/or Cal setting, and think all the readings are still calibrated.
Most of the scopes on my US Naval destroyer were not as good as your scope.
Only the HP 5MHz scope was better, but it was dedicated to a specific system maintenence, and could not be used elsewhere.
Hi, yes. Any valid calibration does list the equipment used (as well as last cal date and due date), the temperature and humidity (wide acceptable range here, and hard to control).
An analogue scope generally has a much better trace and better fine detail. I had to go to a Keysight MSOX3104T in order to get what I would call acceptable displays. Yes it has toys, and yes I use them a lot. But, my Philips PM3070 and PM 3365A have far superior traces for things like CD player eye patterns.
One thing that changes with price on a DSO is the noise in the waveform. The other important thing is the time the scope is blind between acquisitions (one reason I have the Keysight). There are other factors as well. One thing I HATE is the boot time on the Keysight. Earlier DSO's had firmware and didn't run a flipping OS, they just booted, self-tested and ran. My Agilent 54642D is like that, butthe analogue scopes simply turn on and work. That's more my speed.
I have an HP 1722A, it came up with another fault (can't blame the poor old thing). That is a wonderful scope.
My strong recommendation for hobbyists and most audio techs is a good analogue scope. Cheaper, and better in almost every way. Toys? Ask yourself if you really, really do need them. I bet you don't.
An analogue scope generally has a much better trace and better fine detail. I had to go to a Keysight MSOX3104T in order to get what I would call acceptable displays. Yes it has toys, and yes I use them a lot. But, my Philips PM3070 and PM 3365A have far superior traces for things like CD player eye patterns.
One thing that changes with price on a DSO is the noise in the waveform. The other important thing is the time the scope is blind between acquisitions (one reason I have the Keysight). There are other factors as well. One thing I HATE is the boot time on the Keysight. Earlier DSO's had firmware and didn't run a flipping OS, they just booted, self-tested and ran. My Agilent 54642D is like that, butthe analogue scopes simply turn on and work. That's more my speed.
I have an HP 1722A, it came up with another fault (can't blame the poor old thing). That is a wonderful scope.
My strong recommendation for hobbyists and most audio techs is a good analogue scope. Cheaper, and better in almost every way. Toys? Ask yourself if you really, really do need them. I bet you don't.
The accuracy from manufacturers is 3%. There one range can be very good because the manufacturer only use one range for adjusting.I have some VTVMs of the Vintage era, bought for peanuts or given as gifts...
CTR HR-160 and HR-240 - Germany :
View attachment 1212801
Heathkit model V-6 - USA
View attachment 1212802
PACO V-70 - USA
View attachment 1212804
TonFrequenz / ULTRON - Germany :
View attachment 1212805
All of them are accurately calibrated, in fine working condition... They are not ridiculous at all when compared to the modern ones I also have :
But the modern of course can be more precise and easier to use...
T
The Resistor manufacturers use is 1% and meter is 1.5%. The good new the is adjustable to 0.
Some ranges can be off by 2% with bad luck.
The only way to find out is by testing.
The one I built I made all ranges adjustable.
The reason why manufacturer did not use this way was cost savings. Only one range to adjust some models would also have AF and Ohms adjustable too.
If look at a Simpson 260 the use Resistor like this 12.55K Ohms that is a lot better than 1%. They also have a less than 2% error. When test with Fluke and others it was on mark every time. The down side it very costly VOM too.
FYI a DMM should be test accuracy too. I used 3 voltmeters and all 3 was same, I call good till something better comes along
Dave
My experience is that the less expensive DVMs fail cal new out of the box. Also, the ranges are off so cannot be corrected without selecting resistors.
The better meters use trimmed film resistor networks, low capacitance. So Fluke and HP / Agilent / Keysight meters are by far and away your best bet. My HP and newer meters are good to 100 KHz as well.
Yes, my 260 (6p)is as good as yours. But they adjusted each range at the factory. But these were expensive new, and cheaper meters were no comparison. Like everything, you must know your meter. The only way to do that is have your meter calibrated to a "6" level. That reports all readings in tolerance as well as out, and 6 readings per range, per function. Don't be surprised if a budget meter is lying to you. Digital meters are every bit as bad that way.
The better meters use trimmed film resistor networks, low capacitance. So Fluke and HP / Agilent / Keysight meters are by far and away your best bet. My HP and newer meters are good to 100 KHz as well.
Yes, my 260 (6p)is as good as yours. But they adjusted each range at the factory. But these were expensive new, and cheaper meters were no comparison. Like everything, you must know your meter. The only way to do that is have your meter calibrated to a "6" level. That reports all readings in tolerance as well as out, and 6 readings per range, per function. Don't be surprised if a budget meter is lying to you. Digital meters are every bit as bad that way.
As the late Jim Williams said: "A digital scope doesn't lie, but it doesn't always tell the truth." I am sure that was somewhat of an exaggeration when he wrote it.
Just what I need some with booting up.
In 1970's everything was just flip switch and you where up and running.
Dave