Do you have any test equipment in your lab that uses vacuum tubes?

[5065AGuru]

Hi,

Just wondered. The only vacuum tube test equipment I have is an HP 428B clip on Ammeter. It is one of my favorite instruments and warms up in less than 30 Seconds!

Cheers,

Corby Dawson

[capt bullshot]

https://www.eevblog.com/forum/chat/spot-the-test-equipment-%28find-the-hidden-object-with-the-picture%29/msg1412775/#msg1412775

[Berni]

While most of my equipment is rather old it still tends to have at least early ceramic DIP ICs in it.

The one i do have is a Fluke 410B (Precision HV Power supply)
https://testequipment.center/Products/Fluke-410B

It is modern enough for its control circuit and reference to be silicon, but it still uses incandescent lamps as indicators on the front panel. But since this thing can output up to 10kV they couldn't get a transistor to handle that, so there is a big fist sized vacuum tube inside working as a linear pass element to regulate the output.

You would know the thing has vacuum tubes inside without even opening it up because the heater on this tube runs so hot that you can see the bright orange light shining out of all the vent holes in the back area.

[Smith]

I regularely use the HP 412B 2kV HV supply, basicly a 2kv version of the 410B. Its so easy to use, and verry precise. It only needed a new cap for the internal reference a few years back. The downside is the 32mA output, almost 32mA more than 1 need. The output is in series with a relay that should eventually kick in above the 32mA. Colleague got a shock from the his 3kV version once (415B), he was not amused.

[fourfathom]

Do Nixie tubes count?  My old HP  freq counter has these.  I also have a variable high-voltage power supply with some big vacuum tubes, but I haven't plugged it in for a very long time.

[Henrik_V]

In my lab yes, however beside nixies (WG, HP and GR counter, and a V543 DMM) I use a Kepco 2kV Powersupply with a beam power pentode. My museum doesn't count, but in rare situations I use a TeraOhmMeter with a electrometer tube build by Jahre (maybe known as a mica Cap producer) just because it's working and the only gage if have at home for that range.

[Berni]

I regularely use the HP 412B 2kV HV supply, basicly a 2kv version of the 410B. Its so easy to use, and verry precise. It only needed a new cap for the internal reference a few years back. The downside is the 32mA output, almost 32mA more than 1 need. The output is in series with a relay that should eventually kick in above the 32mA. Colleague got a shock from the his 3kV version once (415B), he was not amused.

I have not yet found out what is it like to touch the output of mine, but i really don't want to feel it. The last time i had the output of it arc over to ground it resulted in a loud pop and flash while the protection shut it down.

Mine is a bit whimper at 10mA, but all that appears to be is a relay kicking in at that threshold, nothing actually limiting the output current, so when a short happens the thing just dumps its internal capacitors right out hence why it makes a loud pop when it arcs over, as there is likely amps of current flowing for a brief moment. My solution to that is to add a physicaly large resistor in series with the output so that there is at least something limiting the current.

[TheSteve]

Only VFD's, CRT's, Nixie's and Panaplex displays. I had some spare tubes(and CRT's) but they all went home with Mr Carlson a while back.

[Berni]

Oh and where is the line for it being considered a vacuum tube.

Since quite a few of my equipment still has CRTs and even more has VFDs and those are technically vacuum tubes since they all fire electrons off a heater trough vacuum. Nixie tubes are different since they are essentially glorified neon bulbs (Much prettier to look at tho).

Then you have weird 'tubes' like a traveling wave tube (old high performance RF amplifiers) or things like magnetrons or klystrons that also fit the working principle of a vacuum tube (Tho i don't think you find the last two in test gear).

[Bart1965]

I own a Philips GM4140-00 ("Philoscoop") measurement bridge from 1938. Inside are an EZ 40 rectifier, an EF 40 pentode (another Dutch invention) and the EM 34 "magic eye".

[BravoV]

The only one in the house, Heathkit vacuum tube voltmeter, a freebie meter.

[Psi]

I have an old graph paper servo plotter that uses tubes around somewhere.

And i saved a magic eye valve from going to the rubbish tip a while back.
Not sure what project i'll use it in.

[tautech]

And i saved a magic eye valve from going to the rubbish tip a while back.
Not sure what project i'll use it in.

Gave the only one I've ever had to member Neo in the US as I'll never use it.
He had some project but has never disclosed what. 

Still got a box of assorted tubes that I really must throw out unless you want them ?

[Psi]

And i saved a magic eye valve from going to the rubbish tip a while back.
Not sure what project i'll use it in.

Gave the only one I've ever had to member Neo in the US as I'll never use it.
He had some project but has never disclosed what. 

Still got a box of assorted tubes that I really must throw out unless you want them ?

Only if there's some 12AX7  or EL34 in there. 

[amspire]

I have an ESI precision capacitor measuring transformer bridge that uses valves in the tracking oscillator and null detector. The null detector has a sharp bandpass filter that tracks the oscillator over a range of about 20Hz to 20KHz.

Some of the vacuum tubes do not seem to be easily available.

If it starts to fail, I think I might keep the meters, dials, resonant passive components and precision coupling transformers, but replace the valves with a solid state circuits. Maybe make it battery powered.

I also have an old 5MHz BWD oscilloscope that is a transistor-valve hybrid - haven't used it in decades. It was my first scope and I just never felt like getting rid of it. Fantastic triggering.

A basic valve RF oscillator and Vacuum Tube Voltmeter.  They could end up being converted to solid state.

Richard.

[factory]

I regularely use the HP 412B 2kV HV supply, basicly a 2kv version of the 410B. Its so easy to use, and verry precise. It only needed a new cap for the internal reference a few years back. The downside is the 32mA output, almost 32mA more than 1 need. The output is in series with a relay that should eventually kick in above the 32mA. Colleague got a shock from the his 3kV version once (415B), he was not amused.

Did you mean a Fluke 412B? the HP 41x Series are all meters not HV supplies.

I have loads of test gear with vacuum tubes in my collection, mostly HP, but I also have a Farnell E350, Advance SC1 and a few older ones from Taylor.

David

[tautech]

And i saved a magic eye valve from going to the rubbish tip a while back.
Not sure what project i'll use it in.

Gave the only one I've ever had to member Neo in the US as I'll never use it.
He had some project but has never disclosed what. 

Still got a box of assorted tubes that I really must throw out unless you want them ?

Only if there's some 12AX7  or EL34 in there. 

I think there might be, I'll look tomorrow and PM you.
There's all sorts of old shite, some was Dads from the '40's but most were scrounged from old tele and radio sets.
There's a few bases too, 4, 5 and 8 pin along with some later mini 8 pin bases.

[aix]

I have a Keithley 240A power supply.  I don't get to use it very often, but love the fact that it goes up to eleven!

[med6753]

Besides numerous analog scopes with CRT's I have:

Tektronix Type 191 Signal Generator
Heathkit V-5 VTVM
Heathkit V-7A VTVM
Heathkit S-3 Electronic Switch
Heatthkit AG-9A Audio Generator
Heathkit OL-1 Oscilloscope

All are in working order.
 

[tggzzz]

My Tek time mark generator contains half a dozen or so. Here are pics of two of them:





FFI see https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg2196288/#msg2196288 and subsequent posts.

[ferdieCX]

Heathkit IG-42 RF generator - in use
Tek 310A scope - in work condition, but not in use

[T3sl4co1l]

CRTs -- a few.  Aside from those, not anything that I use regularly.  I have the same VTVM BravoV shared, I think a later model; an RCA "high sensitivity AC VTVM" with a DC mod, and Eico 377 audio and 322 RF generators.  Some audio amps about rounds it out.

I suppose the distributed amplifier counts; haven't had much cause to use it, but it's an original. https://www.seventransistorlabs.com/Images/DistAmp2.jpg

Tim

[KrudyZ]

I have a HP214B pulse generator.
It uses tubes in the output section to deliver 100V into 50 Ohm with 15 ns transition times.
Can't say that it sees a lot of use though...

[schmitt trigger]

Gorgeous!
Nuvistors and metal-can transistors coexisting peacefully within inches of each other.

[Dwaine]

Yep.  Heathkits...  cap checker and vtvm.  Love them...

[bob91343]

My tube gear mostly consists in HP types 400D and 412A voltmeters.  I also have a couple of Boonton Q meters and a GR 1644-B bridge.  My HP 410B is part of my ham station where it measures the output to the antenna.

I am mildly annoyed by the warmup time as well as the high internal temperatures that invite failure.  But I have these instruments and they work very well.

My HP 428A failed and I am unable to repair it; the probe is the problem.

I have plenty of tube type units that are surplus to my needs and would love to trade them off.  They are mostly in my garage awaiting disposition.  Signal generators, voltmeters, bridge, deviation meter, power supplies.

[joeqsmith]

Not including the displays, I have an old grid dip meter.   I also have my old HF radio that I use for testing from time to time.   

[chris_leyson]

Tektronix 130 L-C meter and Heath-Schlumberger SP-2717 PSU.

[Grandchuck]

Only CRT left is inside.

[Martin.M]

something glowing, yes.

[Berni]

Now that's quite the Tek pile.

[Gyro]

I have an HP3400A True RMS voltmeter with the earlier Nuvistor input stage.

[Martin.M]

Tektronix 130 L-C

I love that, it`s one of the best instruments for very small L+C.
It have no problems to test a 0,3pF accurate

[MarkF]

I don't.   But, have you seen Mr. Carlson's Lab

His latest project:

[james_s]

I have numerous bits of gear with CRTs and a nixie display multimeter. I had an audio test oscillator but gave it to another eevblog member because I just wasn't using it.

[artag]

Another Kepco power supply here - HB525, 500V 500mA, 5 x GE7581 (KT66) in the output stage
And some 'scopes with CRTs
And some quite modern instruments with VFDs .. they're thermionic too, right ? Even more so than Nixies !

[med6753]

I have numerous bits of gear with CRTs and a nixie display multimeter. I had an audio test oscillator but gave it to another eevblog member because I just wasn't using it.

That would be me and it's been completely restored. 

[L_Euler]

How about a his one.  Nearly 100 tubes.

[DaJMasta]

No from me, unless you count the nixie clock I made a while ago.

Being a somewhat younger generation, I never had the affinity for older gear, and the size/heat/shipping fragility of even CRT gear generally dissuades me from a lot of it.  I've noticed that when powered down, most of my gear has an LCD screen of some sort....

[james_s]

I have numerous bits of gear with CRTs and a nixie display multimeter. I had an audio test oscillator but gave it to another eevblog member because I just wasn't using it.

That would be me and it's been completely restored. 

Looking good, glad to see it. If only you could find a proper knob to replace the mismatched one it would look almost new.

[vk6zgo]

HP 410C Electronic Voltmeter

HP MODEL 11036A AC PROBE (I'm not shouting, that's how it is listed in the 410C manual)

Leader LSG-11 RF Signal Generator.

BWD 511 Oscilloscope (non- functional at present)

All the other stuff is solid state.(actually my dipmeter used to be a "grid dipper", using a tube, but I modified it to use a FET)

[Stray Electron]

The only one in the house, Heathkit vacuum tube voltmeter, a freebie meter.

  Actually those are pretty decent meters. I had forgotten about them but I still have a couple of them around here somewhere. One of them still has a NIB 25,000 volt probe with it that's never been used.  I think I paid $2 for it and the meter about 10 years ago. Around that time the ham fests were full of these meters and you almost couldn't give them away.

   Other than the Heathkit meters yes, now that I think about it, I still have a lot of tube type stuff.

[Cubdriver]

How about a his one.  Nearly 100 tubes.

A triple nickel is on my wants list.  Even more beautiful with the P11 phosphor!  I have some tube stuff that gets used here and there - Sprague TO-4 and -5, a Tek 575 mod C curve tracer, HP 200CD audio generator, HP 428B clamp-on miliammeter...  Most of the other tube stuff is more for collecting's sake, though it's fun to occasionally use the old HP counters and see all the glowing heaters.





-Pat

[Smith]

I regularely use the HP 412B 2kV HV supply, basicly a 2kv version of the 410B. Its so easy to use, and verry precise. It only needed a new cap for the internal reference a few years back. The downside is the 32mA output, almost 32mA more than 1 need. The output is in series with a relay that should eventually kick in above the 32mA. Colleague got a shock from the his 3kV version once (415B), he was not amused.

Did you mean a Fluke 412B? the HP 41x Series are all meters not HV supplies.

David

You are right, but it does match my HP gear quite well 

I have 3 CRT scopes and a Philips nixie tube voltmeter if they count, but I don't really use the voltmeter.

[PaulAm]

I have and still use on occasion an old Tek 453 with tube HV rectifiers and nuvistors in the H and V sections.  I've had that scope for over 20 years and never had a problem with it.

[notfaded1]

I really like this guy I have:

[Martin.M]

that is fine, yes 

But:

Set it to 12 Volts or 15 Volts to feed any small transistor experiment,
Then press STANDBY and look what the voltage output will do before shutting down finally..  (a typical 30V Transistor will be RIP )
Heathkit made a bullshit there, it may be better to remove "Standby" and type there "WORST CASE SWITCH"

[MarkL]

I have two pieces of test equipment that has vacuum tubes:  A Heathkit IT-28 capacitor checker, and a Spellman 15kV @ 4mA HV supply.  The Spellman has an interesting set of gas voltage regulator tubes in addition to the usual drivers and rectifier tubes.  I've posted photos of it before:

  https://www.eevblog.com/forum/chat/how-many-psu_s-do-you-have/msg393637/#msg393637

I'm still looking for a model ID or schematics if anyone recognizes it.

I also have a tube-powered (5514/811A) Tesla coil which is physically in my lab, but it's not really a piece of test equipment.  It probably has no business being in there given the other sensitive electronics.

[med6753]

I have two pieces of test equipment that has vacuum tubes:  A Heathkit IT-28 capacitor checker, and a Spellman 15kV @ 4mA HV supply.  The Spellman has an interesting set of gas voltage regulator tubes in addition to the usual drivers and rectifier tubes.  I've posted photos of it before:

  https://www.eevblog.com/forum/chat/how-many-psu_s-do-you-have/msg393637/#msg393637

I'm still looking for a model ID or schematics if anyone recognizes it.

I also have a tube-powered (5514/811A) Tesla coil which is physically in my lab, but it's not really a piece of test equipment.  It probably has no business being in there given the other sensitive electronics.

Judging from the photos you posted if those metal 6L6's are original I place that supply earlier than 1960. Perhaps early to mid 1950's. It does appear that the tube on the far right....probably a 5U4....has at some point been replaced. If original it would have had a glass envelope just like your 0A3 VR tubes.

[med6753]

that is fine, yes 

But:

Set it to 12 Volts or 15 Volts to feed any small transistor experiment,
Then press STANDBY and look what the voltage output will do before shutting down finally..  (a typical 30V Transistor will be RIP )
Heathkit made a bullshit there, it may be better to remove "Standby" and type there "WORST CASE SWITCH"

That may be true but that supply is poor choice for that application and is not meant for 12-15V equipment.

[MarkL]

I have two pieces of test equipment that has vacuum tubes:  A Heathkit IT-28 capacitor checker, and a Spellman 15kV @ 4mA HV supply.  The Spellman has an interesting set of gas voltage regulator tubes in addition to the usual drivers and rectifier tubes.  I've posted photos of it before:

  https://www.eevblog.com/forum/chat/how-many-psu_s-do-you-have/msg393637/#msg393637

I'm still looking for a model ID or schematics if anyone recognizes it.

I also have a tube-powered (5514/811A) Tesla coil which is physically in my lab, but it's not really a piece of test equipment.  It probably has no business being in there given the other sensitive electronics.

Judging from the photos you posted if those metal 6L6's are original I place that supply earlier than 1960. Perhaps early to mid 1950's. It does appear that the tube on the far right....probably a 5U4....has at some point been replaced. If original it would have had a glass envelope just like your 0A3 VR tubes.

Sharp eye!  Yes, I had to replace the shattered 5U4 tube when I first got the unit, so I don't know what the original envelope looked like.  It was an attractive target, sticking out on the corner like that.  Alas, the replacement 5U4 eventually died a natural death since that photo was taken and has since been re-replaced with a diode bridge equivalent.

All the other tubes are original except the two HV rectifiers inside the plastic case, at least as when purchased by me.  The HV rectifiers were not performing well.  The unit still works perfectly.

I'd believe 1950's.  Odd that there's not a trace of a model number.  Only "Spellman" on the meter faces.  Maybe it was a custom unit for someone.  I saw a similar one on ebay many years ago, but mounted in a small metal rack case with a flip-up lid to get to the tubes.

[Martin.M]

that is fine, yes 

But:

Set it to 12 Volts or 15 Volts to feed any small transistor experiment,
Then press STANDBY and look what the voltage output will do before shutting down finally..  (a typical 30V Transistor will be RIP )
Heathkit made a bullshit there, it may be better to remove "Standby" and type there "WORST CASE SWITCH"

That may be true but that supply is poor choice for that application and is not meant for 12-15V equipment.

Of coarse, but when they build a unit from zero to 400, that have to work.
OFF is OFF and not enhancing to +60V before OFF, = Bullshit 
Standby with a Heathkit is simply, you remove the + Plug, then it`s trustful OFF.

Martin

[Martin.M]

 



the nice american Set.
The glouchester version is different, they are VVM, not VTVM 

[MaxFrister]

I have a couple.

[med6753]

I have two pieces of test equipment that has vacuum tubes:  A Heathkit IT-28 capacitor checker, and a Spellman 15kV @ 4mA HV supply.  The Spellman has an interesting set of gas voltage regulator tubes in addition to the usual drivers and rectifier tubes.  I've posted photos of it before:

  https://www.eevblog.com/forum/chat/how-many-psu_s-do-you-have/msg393637/#msg393637

I'm still looking for a model ID or schematics if anyone recognizes it.

I also have a tube-powered (5514/811A) Tesla coil which is physically in my lab, but it's not really a piece of test equipment.  It probably has no business being in there given the other sensitive electronics.

Judging from the photos you posted if those metal 6L6's are original I place that supply earlier than 1960. Perhaps early to mid 1950's. It does appear that the tube on the far right....probably a 5U4....has at some point been replaced. If original it would have had a glass envelope just like your 0A3 VR tubes.

Sharp eye!  Yes, I had to replace the shattered 5U4 tube when I first got the unit, so I don't know what the original envelope looked like.  It was an attractive target, sticking out on the corner like that.  Alas, the replacement 5U4 eventually died a natural death since that photo was taken and has since been re-replaced with a diode bridge equivalent.

All the other tubes are original except the two HV rectifiers inside the plastic case, at least as when purchased by me.  The HV rectifiers were not performing well.  The unit still works perfectly.

I'd believe 1950's.  Odd that there's not a trace of a model number.  Only "Spellman" on the meter faces.  Maybe it was a custom unit for someone.  I saw a similar one on ebay many years ago, but mounted in a small metal rack case with a flip-up lid to get to the tubes.

Are the HV rectifiers 1B3's by chance? From what I can see it appears so.

[Martin.M]

hello Max,
that`s very nice,
but the 564 have a pair of dual differential amplifiers in the slots, there is no time base.
Martin

[MaxFrister]

Most of these have been restored and working, but not these 2 scopes.  Note the red tags. 

[med6753]

(Attachment Link)

the nice american Set.
The glouchester version is different, they are VVM, not VTVM 

Yep, my American Heath V-7A VTVM has a British meter courtesy of a fellow blogger in the UK. The original American meter had damaged bearings.

[schmitt trigger]

something glowing, yes.

(Attachment Link)

Many moons ago, I worked in a company whihc had a few of the Tek instruments you are showing here. I know they are VERY HEAVY.

And from the photo, it looks like your lab is located in the attic.

I hope you did not break your back carrying all that stuff up the stairs. 

[EE-digger]

Mostly in good working condition except for the Dumont:

RCA WV98C VoltOhmyst VTVM
Dumont / Fairchild 401 scope
Fluke 412B High voltage supply
HP 400FL ac voltmeter
HP 401 oscillator (tube or FET??)


But alas, none have been used in years 

[vk6zgo]

 I often wonder why HP call the 410C an "Electronic Voltmeter", as it can read Resistance & Current as well.
Still, I suppose other "VTVMs" can do similar things.

Now, this is a "Vacuum Tube Voltmeter"!
https://www.ietlabs.com/pdf/Manuals/GR/726-A%20Vacumm%20Tube%20VM.pdf
It was "AC voltages only"----How does that probe grab you?

I had one for years, until, in a misguided "Nice guy" moment, I donated it to an Electronics Museum.
They had a wonderful assortment of stuff, so I wasn't worried that it wasn't yet displayed.

Years went by, & the decision was made by the "powers that be" to dedicate the museum to the early spark radio equipment used by the coastal radio station that originally occupied the site.
To this end, all the other stuff was "cleared out".

Where to? -----Dunno, maybe landfill!

[med6753]

I often wonder why HP call the 410C an "Electronic Voltmeter", as it can read Resistance & Current as well.
Still, I suppose other "VTVMs" can do similar things.

Now, this is a "Vacuum Tube Voltmeter"!
https://www.ietlabs.com/pdf/Manuals/GR/726-A%20Vacumm%20Tube%20VM.pdf
It was "AC voltages only"----How does that probe grab you?

I had one for years, until, in a misguided "Nice guy" moment, I donated it to an Electronics Museum.
They had a wonderful assortment of stuff, so I wasn't worried that it wasn't yet displayed.

Years went by, & the decision was made by the "powers that be" to dedicate the museum to the early spark radio equipment used by the coastal radio station that originally occupied the site.
To this end, all the other stuff was "cleared out".

Where to? -----Dunno, maybe landfill!

Powered vacuum tube probes were quite common in the 1950's. Today's equivalent is an FET probe.

[vk6zgo]

I often wonder why HP call the 410C an "Electronic Voltmeter", as it can read Resistance & Current as well.
Still, I suppose other "VTVMs" can do similar things.

Now, this is a "Vacuum Tube Voltmeter"!
https://www.ietlabs.com/pdf/Manuals/GR/726-A%20Vacumm%20Tube%20VM.pdf
It was "AC voltages only"----How does that probe grab you?

I had one for years, until, in a misguided "Nice guy" moment, I donated it to an Electronics Museum.
They had a wonderful assortment of stuff, so I wasn't worried that it wasn't yet displayed.

Years went by, & the decision was made by the "powers that be" to dedicate the museum to the early spark radio equipment used by the coastal radio station that originally occupied the site.
To this end, all the other stuff was "cleared out".

Where to? -----Dunno, maybe landfill!

Powered vacuum tube probes were quite common in the 1950's. Today's equivalent is an FET probe.

Certainly!----The 410C has one, but the tube in their probe was a lot smaller than the full sized "lighthouse" tube in the 726A probe!
The large probe was always a problem when looking at 1950s/60s Electronics.

The only time I really found the 726A useful was for aligning AM radios (used in conjunction with my portable one valve "signal generator").
It would have been better, though, if it had a DC range, as I could have looked at the receiver AGC instead of audio out.

It did look really cool, though!

[ferdieCX]

When I was student in the 70's, we used a 726A VTVM in the lab at the technical university.
It still is in our warehouse, waiting to be restored.

[vk6zgo]

I always had a bit of a "soft spot" for General Radio equipment.

At 6WF/WN in Perth, in the "Speech input room" at the Tx site, we had GR Audio generators, when I first worked there.
They had a "mechanical digital" frequency display--- when you turned the frequency control, plastic pieces with numbers on them clicked into place behind a viewing window, where they were illuminated from the rear.
It was quite different from the ordinary "rolling" mechanical display used on hour meters & the like.

i ran into quite a lot of GR stuff over the years, but most of it was more esoteric stuff, which spent more time packed in beautiful polished wooden boxes than ever being used!

[schmitt trigger]

General Radio products  were truly the Rolls-Royces of test equipment for many decades.

Not only they had very high performance, but they were beautifully crafted products.

And the mechanical bits and pieces on the inside were simply awesome.

[MarkL]

I have two pieces of test equipment that has vacuum tubes:  A Heathkit IT-28 capacitor checker, and a Spellman 15kV @ 4mA HV supply.  The Spellman has an interesting set of gas voltage regulator tubes in addition to the usual drivers and rectifier tubes.  I've posted photos of it before:

  https://www.eevblog.com/forum/chat/how-many-psu_s-do-you-have/msg393637/#msg393637

I'm still looking for a model ID or schematics if anyone recognizes it.

I also have a tube-powered (5514/811A) Tesla coil which is physically in my lab, but it's not really a piece of test equipment.  It probably has no business being in there given the other sensitive electronics.

Judging from the photos you posted if those metal 6L6's are original I place that supply earlier than 1960. Perhaps early to mid 1950's. It does appear that the tube on the far right....probably a 5U4....has at some point been replaced. If original it would have had a glass envelope just like your 0A3 VR tubes.

Sharp eye!  Yes, I had to replace the shattered 5U4 tube when I first got the unit, so I don't know what the original envelope looked like.  It was an attractive target, sticking out on the corner like that.  Alas, the replacement 5U4 eventually died a natural death since that photo was taken and has since been re-replaced with a diode bridge equivalent.

All the other tubes are original except the two HV rectifiers inside the plastic case, at least as when purchased by me.  The HV rectifiers were not performing well.  The unit still works perfectly.

I'd believe 1950's.  Odd that there's not a trace of a model number.  Only "Spellman" on the meter faces.  Maybe it was a custom unit for someone.  I saw a similar one on ebay many years ago, but mounted in a small metal rack case with a flip-up lid to get to the tubes.

Are the HV rectifiers 1B3's by chance? From what I can see it appears so.

Close - They're 1G3.

I guess they needed more plate current than the 1B3.  Difficult to tell them apart by looking at the internal structure.  1G3 is a sub for 1B3.

[med6753]

Close - They're 1G3.

I guess they needed more plate current than the 1B3.  Difficult to tell them apart by looking at the internal structure.  1G3 is a sub for 1B3.

According to the RCA Receiving Tube Manual 1G3/1B3 are identical....no difference in characteristics.

[xrunner]

Um ... just a CRT scope - Agilent 54622D mixed signal scope. 

[Addicted2AnalogTek]

I'm only a minor player in the tube gear world.  I've got a few old Tek cal fixtures:

(2) Type 106 square wave generators
067-0502-01 amplitude calibrator
Type 191 constant amplitude sine wave gen
067-0532-01 constant amplitude sine wave gen
067-0532-00 constant amplitude sine wave gen (in pieces)

This of course excludes all of the CRTs

[MarkL]

Close - They're 1G3.

I guess they needed more plate current than the 1B3.  Difficult to tell them apart by looking at the internal structure.  1G3 is a sub for 1B3.

According to the RCA Receiving Tube Manual 1G3/1B3 are identical....no difference in characteristics.

Interesting.  I was looking here:

  http://tubedata.milbert.com/sheets14.html

Some of the data sheets do show them to have the same ratings.  Some don't.

I also have a copy of the RCA Receiving Tube Manual.  One thing that's different is that the 1G3 has a slightly smaller height (3+9/16" vs. 4+1/16").

My sub book shows 1G3 as a sub for 1B3, but not the other way around.

[n5al]

Apart from CRTs and VFDs, none of my test equipment uses vacuum tubes.  I have a HF linear amplifier that uses 3-500 tubes, but that's not test equipment, of course.

[zitt]

Hikok 605A Tube Tester - missing main needle meter.



I'd like to get this tester working so I can resurrect my Grandma's AM Radio from 1930s which is also a vacuum tubes.

[Martin.M]

A triple nickel is on my wants list.  Even more beautiful with the P11 phosphor! 

hello Pat,
look for a P7 dual coating screen, they have a fast blue and a slowly greenyellow, so when the dot is slowly running its blue and draws a grennyellow line.
That is the most cute CRT Tek have build. P7 is very useful for slowly frequencys about the very long delay of the greenyellow. In fast actions it looks blue only.
The delay time of the greenyellow will reach 2 seconds, the blue have only ms

Martin

Picture = Triple Nickel, P7
the second picture is a 551 Dual Beam,with options  P11 and 12kV mod (= another graticules glass, with a text below)

[Cubdriver]

Beautiful scopes, Martin - you have an awesome collection of them!  I'm keeping my eyes open, but I fear like many of the heavy old Tek iron that they're getting more and more rare as audiophools gut them for their dual triodes and discard the carcasses.  That really burns me up!

Keep up your preservation efforts!!

-Pat

Edit to add - thanks for the tip on the P7 dual phosphor - I'd read about it, but never gave it much thought - it looks like a great combination!

[Martin.M]

as audiophools gut them for their dual triodes and discard the carcasses.  That really burns me up!

they are waiting for the next youtube video:  "we build a scope using a Marantz Tuner" 

[Bill158]

Does a FLUKE 5215A power amp count?  This is used with the 5200A AC Calibrator to generate up to  1000 Volts RMS, up to 100 KHz.  Uses 4 ea. 4X150A transmitting tubes in the output.  This thing is a real "widow maker" if you are not careful.  It will also smoke any DVM that isn't rated at 1000 Volts AC at any frequency.  You need to check the specs on the meter you are trying to calibrate before applying the AC voltage.  It also doubles as a swell lab heater all year around.
Bill

[Michael Lloyd]

I've got a few. Some I have duplicates. Some are a little rough but they work. All are not "on" the bench but I can use them as needed or desired. I have a very large Tektronix o-scope that's full of tubes but I haven't done anything with it, yet.

Some stuff I don't have photos of. Like: An Eico-147A signal generator, Eico 315 signal generator, Eico 950 capacitor tester, and the queen of my bench - an Eico 249 VTVM. It shows up in at least one of the photos below

Tektronix 422 in black























Knight 83Y135 Signal Tracer. No photo at the moment

I restored this old oscilloscope. It was an adventure

After


Before (the inside looked worse)
















These two beaters work now:

Technically this isn't usable because it's not restored yet. I don't have a model number or schematic but I haven't looked very hard for it either

[james_s]

I'd forgotten, I do have a Heathkit IP-32 power supply that has tubes in it. It's not something I use often, but on occasions where I need a relatively high regulated DC voltage there's nothing else I have that can deliver.

[bob91343]

Those are wonderful pictures!  I wish I had the patience to photograph some of my gear.  I have plenty of it that uses tubes.

In fact, yesterday I managed to get working again my venerable HP 428A clip-on dc millliammeter.  Nice to have it again.

[mmagin]

Technically this isn't usable because it's not restored yet. I don't have a model number or schematic but I haven't looked very hard for it either

That is the military, possibly second-source (non-HP) version of the HP 410b. 

[Martin.M]

VTVM:

Sennheiser RV55 is a AC mVM
Grundig RV3 is a VTVM with a warm probe for HF

RV55 is a wonder about the s/n what it have in the < 1mV range, made with tubes. Here we find the experience of microphones technology (under-heated triode system)

amazing: Sennheiser is a sponsor company at the Makerfaire Hannover, there is a friendship bec. I run there always any glowing history of them..
This year I got a very lot of technical manuals from them, this books are now avaiable for all who do restorations. Also they have given me a RV54 made by LABOR W (Laboratories Wennebostel, that is the rather old name of them ! )





 

[ferdieCX]

VTVM:

Sennheiser RV55 is a AC mVM

(Attachment Link)

The BNC T in the picture looks like the ones that came with the VAXstations.
Is that correct ? 

[Martin.M]

I really don`t know that. Have saved the life from an old SGI, it was not possible to put it here in the room.
It may be enough, no VAX here

Martin

[Martin.M]

lo-Ohm-Meter, 4wires testing. Full glowing 

< 1/3/10/30/100/300 Ohms full scale. This Oldie can test ESR at 10kHz sine also.
It is possible this is the last one, it was made for internal use in the own manufacturings, by Philips NL.
Picture: testing a 10 ohm







 

[001]

I see a lot of tube power supplies in the tread

What way You are using tube PS for? I mean in 2019

I remember what all similar PS have high voltage spikes if You turn it off and no current limit anyway 

[vk6zgo]

I see a lot of tube power supplies in the tread

What way You are using tube PS for? I mean in 2019

I remember what all similar PS have high voltage spikes if You turn it off and no current limit anyway 

If you are using them with tubes, such devices have a high degree of immunity to high voltage transients, as do many high voltage solid state devices, which are often used with relatively simple supplies.

Many quite advanced tube power supplies exist which do have current limiting.
Turn off of tube supplies can mean many things, such as turning the whole thing off, where, as the heaters are still hot, will result in a graceful drop in voltage to zero as they cool down.

None of the tube power supplies I remember using had a separate switch for applying already present voltage to the output terminals.
They were pretty much "turn the thing on from scratch".

Transmitter power supplies are an exception, where they sometimes applied HT progressively to different sections of the equipment.

The only comment I have seen regarding "voltage spikes" is where people are using tube based supplies to provide solid state type voltage levels.
This is a long way from the original intended use of these power supplies.

[Michael Lloyd]

Mine gets used in vintage Ham radio circuits (tube).

[SLJ]

Half my bench is vacuum tube equipment.


That's mostly what I work on.

[TheUnnamedNewbie]

While technically not vacuum tubes, I do have a multimeter that still uses nixies (keithley 164). Does that count?

[001]

This is a long way from the original intended use of these power supplies.

Ok
What is You favorite tube power supply?

[vk6zgo]

This is a long way from the original intended use of these power supplies.

Ok
What is You favorite tube power supply?

Good comeback!

I don't have one
Standalone tube power supplies were never very common.

You might have found some in University or Tech College Labs, or at equipment Manufacturers.
From memory, there was one at the 6WF transmiier site where I worked many moons ago, & that's about the only one I remember outside Tech College.

Most tube supplies were part of a complete piece of equipment, & were fairly straightforward designs, so the requirement for such a supply "on the bench" was fairly rare.

PS:-The above may sound as if I am contradicting my earlier posting, but there were many designs around for standalone supplies in books, magazines, etc, although it was unusual to see one "in the flesh".

[0culus]

I seem to remember a Mr. Carlson's Lab episode where he demonstrates a rather beefy tube supply he uses on his bench.

[bob91343]

I have one of those beefy power supplies.  I never have used it.

[001]

I have one of those beefy power supplies.  I never have used it.

So what the reason to own it? 

[TimFox]

Because it's a free country?

[schmitt trigger]

Although I don't have the joy of owning a vacuum tube based test equipment, I do have a vacuum tube tester.
That must count as something.

[bob91343]

The reason to own it is that nobody wants to buy it.  I don't want to throw it away.  It works great.  I have owned it for about 40 years.  Every couple of years I switch it on to see if it still works.  The only problems it has are that one of the meters has a crack in the glass and one of the toggle switches gets intermittent from lack of use.

It's nice, a big job in a rack panel, two main outputs 0-300V and 0-500V which can be put in series for 0-800 V.  Also filament supply, 6.3V.  One supply uses a variac.  Perfect for bench testing of a 100W transmitter or a big tube type audio amplifier, servomechanism, or the like.  They are closely regulated outputs and the unit is top quality, Dressen-Barnes.

I am saving it for swap I guess.  What would you do with it?

[med6753]

Nothing like encouraging destruction of vintage equipment by audio phools. This clown includes in his ad "got Bulge boy tubes in it"

https://www.ebay.com/itm/Vintage-Working-Tektronix-561B-Oscilliscope-2A60-AMPLIFIER-2B67-time-tube-type/113715031978?hash=item1a79f1afaa:g:45QAAOSwJvVcN8zE

[0culus]

I'm super tempted to buy it just to prevent that. But this clown probably wouldn't pack it worth a shite. 

[mansaxel]

I have a (newly resurrected, see here -- hp) -- 428b, bought as for-parts from the US. With a probe!  I have wanted it since I read about it in (I think) the -- hp -- 410b service manual.

I do not own a 410b; that auction fell through. This time.

I do own a Marconi TF1041B VTVM of 1968 vintage with the whole shebang including a heated probe, also working.

Finally, an Euratele 412 Abgleichsender, also working. My wife found it for me at the large Eskilstuna ham flea market. Yes, I have the best wife in the world.

The Euratele range was, I understand, something of a German Heathkit, "some" assembly required. It does all then-current broadcast bands, and some more on shortwave. Have verified der Abgleichsender on Band II FM (in Sweden, it is allowed to operate a very, very weak Band II FM transmitter for local perusal), and it apparently works across the house, and probably further if you connect a decent antenna to it.

There will undoubtely be more valve equipment coming my way.

[Martin.M]

Congratulation to that wife 

Don`t forget some of the larger system needs some A for glowing.
When I start here more then 3 from the scopes the fuse of the workroom will stop the job 
Martin

[med6753]

When I start here more then 3 from the scopes the fuse of the workroom will stop the job 
Martin

Are you surprised by that? 

[mansaxel]

Congratulation to that wife 

Don`t forget some of the larger system needs some A for glowing.
When I start here more then 3 from the scopes the fuse of the workroom will stop the job 
Martin

I have a three-phase 16A 230/400V supply to the workshop. It is shared with the computers (including a 2KVA UPS with ~270 kilos of battery bank) and the machine workshop, where there are several 3-phase machines like drill press, air compressor, etc. I do not expect fuses blown, but sometimes the RCCB takes a dislike to the devices I connect...

[Martin.M]

left side from the work table:

Tek 551 (850W)
Tek 555 (1000W)
Tek 555 (1000W) yes, it`s a pir of them
Tek 556 (850W)
Tek 565 (500W)
Tek 549 (600W)
Tek 533A (< 500W)

at the right side from the table ...

 

[mansaxel]

left side from the work table:

Tek 551 (850W)
Tek 555 (1000W)
Tek 555 (1000W) yes, it`s a pir of them
Tek 556 (850W)
Tek 565 (500W)
Tek 549 (600W)
Tek 533A (< 500W)

at the right side from the table ...

 

Impressive.

L1: 533A+549+565 = 1600W
L2: 555+666 = 1850W
L3: 555+551 = 1850W

L1 is always loaded more than the others, so will get the lowest load. Still, all three phases come in under 10A, with headroom.

Oh, you don't have threephase "Drehstrom" in your workshop? I've lived in apartments with 3x16A main fuse. Sweden, home of ASEA (the A in ABB) and three-phase!

[Martin.M]

not so easy to calculate that, it was the e left side of the table 
If you are interested I have some details at https://www.eevblog.com/forum/testgear/vintage-tek-restoration-pictures-by-martin/

greetings
Martin

[Larryc001]

Some of mine.

[0culus]

Daaaaang, dude. Hope you have strong floor joists. 

That's a super awesome collection. One day I hope to own one nice example of a Tek vacuum tube scope. Maybe.

[xrunner]

Some of mine.

Wow! 

[Cubdriver]

Schweet bunch of scopes there!!   

-Pat

[Michael Lloyd]

Some of mine.

Wow, are you Paul Carson's neighbor??

[Cubdriver]

Some of mine.

Wow, are you Paul Carson's neighbor??

Or did you visit Germany and clean out Martin's place?

[VK5RC]

Lovely gear, I can imagine the sound and smell of them being used!
Rob

[Larryc001]

I am having trouble posting but hopefully I can figure it out and put up a few more pictures.

[David Hess]

I have a pair of 500 series Tektronix oscilloscopes, a Tektronix 184 time-mark generator, and a pair of ESI 250DA impedance bridges.

[Larryc001]

A few more.

[Larryc001]

First transistor scope the 321 and 321A.

[Muttley Snickers]

    

[Larryc001]

I should clarify my response and photos. Although all of my many scopes are fully working, I don’t really use them for troubleshooting. They are really a collection. As the topic was more like vacuum tube instruments being actually used, my posts were a bit off topic. I have a 2465A, a 2213, and a 2445 that I use to work on the big scopes. My apologies.

[0culus]

I should clarify my response and photos. Although all of my many scopes are fully working, I don’t really use them for troubleshooting. They are really a collection. As the topic was more like vacuum tube instruments being actually used, my posts were a bit off topic. I have a 2465A, a 2213, and a 2445 that I use to work on the big scopes. My apologies.

Absolutely nothing wrong with that. Thanks for sharing. 

[BravoV]

I should clarify my response and photos. Although all of my many scopes are fully working, I don’t really use them for troubleshooting. They are really a collection. As the topic was more like vacuum tube instruments being actually used, my posts were a bit off topic. I have a 2465A, a 2213, and a 2445 that I use to work on the big scopes. My apologies.

You're wrong, that 2465A, 2213 and 2445 still fall into "vacuum tubes" test equipment as for it's screen. 

Thanks for sharing the collection. 

[Larryc001]

Here is an interesting website from Julian Bunn, a long time electronics enthusiast and Caltech professional. He has a lot of stuff here including the Tektronix portion:

http://pcbunn.caltech.edu/jjb/Tektronix/tektronix.htm

His main site is at:

http://pcbunn.caltech.edu/default.htm

Many tubes here!

[David Hess]

You're wrong, that 2465A, 2213 and 2445 still fall into "vacuum tubes" test equipment as for it's screen. 

I excluded CRT oscilloscopes because EEVBlog does not allow posts that long.

[BravoV]

You're wrong, that 2465A, 2213 and 2445 still fall into "vacuum tubes" test equipment as for it's screen. 

I excluded CRT oscilloscopes because EEVBlog does not allow posts that long.

Well, in that case, you need a sanctuary for that kinda post, anytime, you're very welcome at TEA.   

[SeanB]

Anybody have a use for a GE 1358x CRT though, has slight burns on it, from being run at high power as a chart recorder, but otherwise working, complete with the mumetal shielding can. Going to be expensive though to ship, but I can almost guarantee it will survive, will be packed HP style.

[Yansi]

I have a couple of old Russian RF generators, that have some pretty interesting stuff inside, including a bunch of twobs. These are a the G4 series generators, that go from about 1GHz to up to some tens of GHz.

The front looks like this:



And what's inside, see below. Pretty impressive stuff, especially that mechanical linearity trimming. 

See this thread for photos of the inside: https://www.eevblog.com/forum/rf-microwave/russian-microwave-signal-generator-g4-80-teardown/

//EDIT: Sorry, I have forgot that I have already uploaded the teardown here ^^

[Larryc001]

This was “Spotted this randomly, a lovely shot of a Type 531A at NASA, dated Dec
31, 1960” by another enthusiast.

https://www.flickr.com/photos/nasacommons/15708311313/in/contacts/

[vk6zgo]

This was “Spotted this randomly, a lovely shot of a Type 531A at NASA, dated Dec
31, 1960” by another enthusiast.

https://www.flickr.com/photos/nasacommons/15708311313/in/contacts/

And it looks uncannily like it is displaying a field rate analog video signal.
Maybe " Display something to make it look technical "?
OK, it could be that the bottom line is just "no input", & the juxtaposition of the square wave is just a coincidence.

[David Hess]

Oh, I forgot, I also have an HP TS-510/U UHF signal generator.

[Tubesrule]

Okd thread but I'm bored and is midnight  I have a heathkit magic eye, a couple of tube testers and something else some where.  Oh yes my heathkit IG72