Hickok 600A

[Retrovert]

When you consider how many of these machines were used as portables on service calls and in military applications,I wonder just how critical this was and how often it was practiced. And I am one of the guilty ones

But it says so in the datasheet, so it must be true!

I don't know if it is a storage and vibration issue, where the droplets gradually coalesce into something larger, or a warning because it can happen under certain circumstances and better to warn everyone and thereby avoid customer returns and complaints.

 

[Retrovert]

RCA Transmitting Tubes,Technical Manual TT-5 (1962)

Rectifier Considerations: Mercury-Vapor Tubes

A mercury-vapor rectifier tube must be handled with special care to prevent dispersion of the liquid mercury from its normal position at the bottom of the bulb. Spattering of the mercury over other portions of the bulb or on the anode or filament must be avoided because it may lead to internal shorts or arcs when the tube is placed in operation. A mercury-vapor tube should always be transported, stored, and operated in a vertical position with the filament end down, and should never be jarred, shaken, or allowed to rest even momentarily in a horizontal position. The tube should never be rocked or allowed to snap into place in its socket.or mounting, and should be protected against excessive equipment vibration.

If spattering occurs, the dispersed mercury must be completely reconcentrated before the tubes are placed in service by means of special preheating and conditioning treatments.In the preheating treatment, the mercury-vapor tube is operated at normal filament voltage, but without anode voltage, for 30 minutes to assure complete vaporization of the mercury content. When filament voltage is removed at the end of this preheating period, most of the vaporized mercury recondenses in a pellet or pool at the bottom of the bulb. The conditioning treatment is then applied to flash out any mercury which may have condensed on the bulb walls or in the vicinity: of the anode and filament seals. In this treatment, the tube is operated at normal filament voltage and at about one-sixth normal anode voltage for 5 minutes. The anode voltage is then gradually increased over a period of about 30 minutes to the normal operating value. If an internal flashover occurs at any time during the conditioning treatment, the anode voltage should be reduced until the flashover ceases. It should then be held at this reduced value for a. few minutes to assure complete vaporization of the mercury before the treatment is resumed.
​

 

[Sam Cogley]

RCA Transmitting Tubes,Technical Manual TT-5 (1962)

Rectifier Considerations: Mercury-Vapor Tubes

A mercury-vapor rectifier tube must be handled with special care to prevent dispersion of the liquid mercury from its normal position at the bottom of the bulb. Spattering of the mercury over other portions of the bulb or on the anode or filament must be avoided because it may lead to internal shorts or arcs when the tube is placed in operation. A mercury-vapor tube should always be transported, stored, and operated in a vertical position with the filament end down, and should never be jarred, shaken, or allowed to rest even momentarily in a horizontal position. The tube should never be rocked or allowed to snap into place in its socket.or mounting, and should be protected against excessive equipment vibration.

If spattering occurs, the dispersed mercury must be completely reconcentrated before the tubes are placed in service by means of special preheating and conditioning treatments.In the preheating treatment, the mercury-vapor tube is operated at normal filament voltage, but without anode voltage, for 30 minutes to assure complete vaporization of the mercury content. When filament voltage is removed at the end of this preheating period, most of the vaporized mercury recondenses in a pellet or pool at the bottom of the bulb. The conditioning treatment is then applied to flash out any mercury which may have condensed on the bulb walls or in the vicinity: of the anode and filament seals. In this treatment, the tube is operated at normal filament voltage and at about one-sixth normal anode voltage for 5 minutes. The anode voltage is then gradually increased over a period of about 30 minutes to the normal operating value. If an internal flashover occurs at any time during the conditioning treatment, the anode voltage should be reduced until the flashover ceases. It should then be held at this reduced value for a. few minutes to assure complete vaporization of the mercury before the treatment is resumed.
​

Considering how many Hickoks mounted their 83 tubes horizontally, in cases that were carried around to various locations by electronics techs and set up for use without waiting around forever, one could assume that this is probably a bit paranoid.

 

[Retrovert]

Considering how many Hickoks mounted their 83 tubes horizontally, in cases that were carried around to various locations by electronics techs and set up for use without waiting around forever, one could assume that this is probably a bit paranoid.

Some speculation.

Consider if the intent is to prevent damage to the cathode's emission surface when the mercury plasma has not yet formed. Mercury rectifiers can be easily damaged by current flow before the plasma is established, and the guides all warn against it. A tube tester pulls such low current through the tube that such cathode damage occurs at a far lower rate. It will occur, of course, but the cathode is fairly robust in a rectifier and the repeated on-off cycles are likely far more destructive to the heater and this will prove to be the limiting factor in lifespan in a tube tester, not whether current is pulled before the rectifying plasma is well formed.

 

[tube-a-lou]

Okay guy's, I'm beginning to think getting this tester was a bad idea with all this mercury and all.
How do I tell this tube in mine is going to be good or not!

 

[Sam Cogley]

Just about every good tester used a mercury vapor rectifier. If you're that worried about it, build the solid state replacement mentioned in an earlier post.

 

[tube-a-lou]

Sweet! Hey what the difference between a 600a and 800a hickok? Is the 800a
better?

 

[Retrovert]

Hey what the difference between a 600a and 800a hickok? Is the 800a better?

As I recall, when I looked into buying a tube tester the only difference between the older models was that the 800A adds 9-pin and 12-pin compactron support.

The 6000A, very similar to the 800A, has compactron and novar support, but does not support the older 4/5/7 sockets. Whereas the 6000 (non-A) does have the older support but not the newer. The 6000 series is also a Gm tester.

The 6000 series differs from the 600 series in that it has replaceable sockets, which plug in as a block, which is likely not an issue unless you are doing bulk testing, in which case you'd use the socket extenders to protect the sockets from over-insertions.

The type of tester best suited for your needs depends on whether or not you plan to work on the old radios or will be working on more modern equipment. One can, of course, test the older tubes using easily-wired adapters, and determining what the switches should be set for. But it will not be as automated as one might like.

 

[tube-a-lou]

I'm going to use it for 7, 9, and 8 pin tubes, I'm looking at the 800a and it's a good price so far
but that could change. So your saying that that not much difference between the two just
different sockets and age??

 

[Retrovert]

I'm going to use it for 7, 9, and 8 pin tubes, I'm looking at the 800a and it's a good price so far
but that could change. So your saying that that not much difference between the two just
different sockets and age??

I suggest you do some reading about the differences between units to select a tester which meets your needs.

 

[Sam Cogley]

As I recall, when I looked into buying a tube tester the only difference between the older models was that the 800A adds 9-pin and 12-pin compactron support.

The 6000A, very similar to the 800A, has compactron and novar support, but does not support the older 4/5/7 sockets.

There were two 6000A drop-in socket pods. One with compactron and novar sockets (the one that's most commonly seen), and one with the 4-pin, loctal, etc. sockets. They both have standard octal, 7-pin, and 9-pin sockets. I keep the older style pod on my 6000A, as I almost never mess with compactrons.

 

[Retrovert]

There were two 6000A drop-in socket pods. One with compactron and novar sockets (the one that's most commonly seen), and one with the 4-pin, loctal, etc. sockets. They both have standard octal, 7-pin, and 9-pin sockets. I keep the older style pod on my 6000A, as I almost never mess with compactrons.

I thought the plugin itself determined the difference between the straight 6000 and the 6000A, that the two units were identical aside from which plugin was installed. So putting the older plugin into a 6000A made it into a 6000. Is that correct?

The 6000A had both plugins as an option? The 6000 was early 1960s and the 6000A was late 1960s.

I the CA-4 and CA-5 plugin added the newer features to the 6000, but also allowed some of the older tubes to be tested on the 6000A, I think.

What's the number on the older plugin? I should get one for my 6000 because I, too, never use the compactrons, although they are cute little things (inexpensive too!) that I should play with at some point.

 

[Sam Cogley]

I thought the plugin itself determined the difference between the straight 6000 and the 6000A, that the two units were identical aside from which plugin was installed. So putting the older plugin into a 6000A made it into a 6000. Is that correct?

The 6000A had both plugins as an option? The 6000 was early 1960s and the 6000A was late 1960s.

I the CA-4 and CA-5 plugin added the newer features to the 6000, but also allowed some of the older tubes to be tested on the 6000A, I think.

What's the number on the older plugin? I should get one for my 6000 because I, too, never use the compactrons, although they are cute little things (inexpensive too!) that I should play with at some point.

Common, but erroneous, information on several tester webpages. The 6000 has an 11 pin plug on the pod (from what I've read), the 6000A has a 12 pin plug (just verified on one of my pods). 6000A adds transistor and solid-state diode testing, and one more selection on the "Function" switch. Of note, I have seen a picture of one marked as a "6000" with the transistor test functions and the "H" setting on the "Function" switch. Best guess is that it's a transitional model or a misprint, and either way it's likely much more of a 6000A than a 6000.

The manual for my 6000A is dated 1964.

I'm not sure what the part number is for the 6000's older socket pod, if it indeed has an 11 pin octal-style plug. The part number should be in the manual. 6000A's is 1050-145. I got ridiculously lucky and found one through Bartertown not long after I bought my 6000A.

There is also an unusual 6000B revision which appears to be a stripped-down, discount model of the 6000A. It has one less option on the "Function" switch than the 6000, no transistor/diode test functionality, and fixed sockets which mirror the "modern" socket pods for the 6000 and 6000A.

 

[Retrovert]

Common, but erroneous, information on several tester webpages.

The interwebs of ten thousand lies. Sigh.

The 6000 has an 11 pin plug on the pod (from what I've read), the 6000A has a 12 pin plug (just verified on one of my pods). 6000A adds transistor and solid-state diode testing, and one more selection on the "Function" switch.

I knew about the transistor testing, but the reports were that the two were otherwise equivalent except for the early vs. late tube sockets. The CA-5 plugin was supposed to add to the 6000A the ability to test the mercury rectifier, which otherwise was not testable on the 6000A, and adds a few more of the later era tube options, I think. The 6000B is the functionally reduced unit, circa 1963 according to Padgett.

I bought a Hickok 870 for transistor testing, as it was far more advanced than the 6000A, but it requires a rebuild and recalibration, and I haven't needed to do transistor testing beyond what a multimeter does. Now I need to match some output pairs, so it's time to get the 870 restored.

 

[soundmotor]

I don't know anyone who has broken a tube rectifier.

Yeah, I am struggling pretty hard to envision how the one in my 539 would get broken? The 539 moves between the place I store it and the place I use it.

Although they are quite close together I've (so far) resisted the urge to throw it from one spot to the other although that would undoubtedly be quicker.

 

[Retrovert]

Yeah, I am struggling pretty hard to envision how the one in my 539 would get broken? The 539 moves between the place I store it and the place I use it.

Although they are quite close together I've (so far) resisted the urge to throw it from one spot to the other although that would undoubtedly be quicker.

Units which are constantly moved from shop to car to home to car to shop, i.e. by repair people back in the day, could have shocks to the glass envelope which might eventually fracture at a weak point. Or the tube could work loose from the vibrations. This is why tubes in high-vibration environments had the wire bails to prevent movement from starting. But, yeah, it's a pretty unusual situation.

Dropping CFLs, having the break when being removed, or breaking long fluorescent tubes, however, is a lot more common.

 

[soundmotor]

Units which are constantly moved from shop to car to home to car to shop, i.e. by repair people back in the day, could have shocks to the glass envelope which might eventually fracture at a weak point. Or the tube could work loose from the vibrations. This is why tubes in high-vibration environments had the wire bails to prevent movement from starting. But, yeah, it's a pretty unusual situation.

Dropping CFLs, having the break when being removed, or breaking long fluorescent tubes, however, is a lot more common.

My convoluted point was that the likely majority of tube testers in use now live a fairly sedentary existence vs. in the day.

 

[Retrovert]

My convoluted point was that the likely majority of tube testers in use now live a fairly sedentary existence vs. in the day.

Yes, I understand that and agreed with you that, absent a peripatetic lifestyle of the down-and-out tube tester riding the rails, a mercury-vapor rectifier tube experiencing a broken envelope is going to be very rare, if not singularly so.

Even the guitar players I know, who thoroughly abuse their heads, only see broken tubes when the amplifier is dropped from a height. That's not to say it doesn't happen, particularly out of the back of a van. Just that it takes this sort of lifestyle.

The more common cause of rectifier-tube failure in a tube tester, as I mentioned, is going to be failure from repeated heater cycling.

 

[Sam Cogley]

I had a 12AX7 (which still had silver getters, holding a vacuum) explode in my fingers while pulling it from an organ. It was an RCA blackplate...

Still an unusual event. Only one that's ever shattered like that, and I've handled thousands of tubes at this point.

 

[toxcrusadr]

I had a 12AX7 (which still had silver getters, holding a vacuum) explode in my fingers while pulling it from an organ. It was an RCA blackplate...

Still an unusual event. Only one that's ever shattered like that, and I've handled thousands of tubes at this point.

I was with one of our resident tube jockeys, Jaymanaa, at a Twangfest a couple years ago, down in his basement shop. Apparently he was showing someone a very expensive gold plated tube in the box. They looked at it from one end with the lid open, then turned the box over for some reason with the lid still open. Tube slid right out onto the concrete. D'OH!

Edit: CFLs and fluorescent tubes have very minimal mercury these days. Quite a bit less than an old 83, I would venture.