A Look at Stark Tube Testers
There were many brands of vacuum tube testers available during the halcyon days of tube technology. Many of these brand names are but a faint memory today, while others have garnered attention bordering on hysteria, thanks to eBay. One tube tester brand has been granted the cult-status of being inarguably ‘the best’ available; Hickok. You can read all about Hickok tube testers elsewhere on these pages, although I will remind you that the same artisan elves manufactured the same tube testers to be ‘branded’ with names other than Hickok. One of those names was Stark.
What little I know personally about the company called Stark is as follows. Stark was an electronics manufacturer located in Ajax, Ontario during the golden days of radio. You can also find examples of Stark VTVM’s, signal generators, and even oscilloscopes. It appears that Stark actually manufactured their own test equipment, including the earliest tube testers. The model numbering scheme to Stark test equipment make absolutely no sense to me, and in a minute you’ll be as confused as I am. The earliest Stark tube tester is probably the Model 9-11. An example is seen below.
The Model 9-11 is a simple emission tester, and obviously doesn’t test very many tube types. The small chart affixed to the top lid lists the tube types that can be tested. What you may note is that there is a very limited switching array, and the tester itself is very small and compact. As more tube types were developed, the ‘upgraded’ Model 9-55 was introduced, with additional tube sockets. An example is seen below.
Now things get very confusing. It appears Stark decided not to manufacture their own tube testers anymore, and licensed the ‘mutual conductance’ circuit from Hickok. Another theory has it that certain tube testers were shipped as parts into Canada, and assembled. This would help eliminate import tariffs, as the tube tester is now manufactured in Canada! Regardless of the reasons, the bulk of the tube testers marketed by Stark now had clearly indicated on their panel that they were ‘Under License of Hickok Electrical Instrument Company’. The circuit inside was the standard Hickok fare; an 80 yielded unfiltered DC for the plate voltage supply, while a 5Y3 gave unfiltered DC for the screen grid and bias voltages. The earliest Stark/Hickok tube tester was probably the Model 9-66, produced from approximately the late 1940’s and all through the 1950’s. An example is seen below.
The Model 9-66 was produced for a very long time, and could have been housed in a case with one of three coverings; tweed (the oldest of the 9-66 testers), gray, or black. There was a 9-66A (either in gray or black), and these simply had a few extra sockets to test Compactrons, Duodecars and Nuvistors. The 9-66A may also have a secondary panel affixed to the top immediately above ‘main’ panel, and the add-on panel features sockets to help test even newer tube types. The main control panel has a familiar ‘feel’ to it; if you can operate a Hickok, you’ll have no trouble with your Stark. The 9-66A is an exceptional tester; it can test nearly every tube type you’ll ever encounter, and it has a ‘noise test’ sorely lacking on many other tube testers. This would be an ideal tester regardless of whether you were repairing antique radios or a variety of guitar amplifiers. Some ‘experts’ would have us believe the Stark 9-66 resembles the Hickok 750, while others argue the Stark 9-66 is based on the Hickok 533. I personally believe the Stark 9-66 looks a lot like both the Hickok 533 and the 750. Either way, the sockets have been moved into the upper left corner, adding to the mystery. Why not utilize the same panel, and have them silkscreened for whomever you decide will market the actual tester? You now have to stock a supply of each panel, and that simply adds to your inventory costs.
The next Stark model to have been marketed was probably the Model 8-77, produced from approximately the mid 1950’s through the 1960’s. The Model 8-77 is loosely based on the Hickok 6000, but does not have the transistor-test function. Also note that the sockets are fixed directly to the panel rather than being on a raised platform. The Hickok 6000 testers had a few variations themselves, so accurately dating the Stark 8-77 tester isn’t easy. The Model 8-77 has a very unique (oddball?) way of checking for leakage or shorted elements; you may notice the bank of neon bulbs in the lower right-hand corner in the photo below. Certain Hickok tube testers also ‘featured’ these neon bulbs, but often covered with a small ‘hood’, to make viewing their status much easier. This is sadly absent from the Stark 8-77.
The Model 8-77 has a few other deviations from the ‘typical’ Hickok circuit. For starters, there is no ‘Line Adjust’ control. Actually, many of the typical Hickok push-buttons are absent. However, the ubiquitous red ‘P4’ button is still present, albeit now called ‘Test’. Other oddities are as follows.
- The ‘Function’ switch, seen just to the lower left of the meter movement, completes the socket connections! There are not (m)any other Hickok tube testers that come to mind having this ‘feature’.
- There is a ‘Filament Continuity’ button. Why?
- You cannot use the ever familiar JR 5347-2 to test say a 6L6. Those settings will work on many Hickok tube testers, and even with the Stark 9-66. However, now the 8-77 sees fit to have the settings HS 5348-1. I have no idea why. The 5348-1 part makes even more sense than the ‘original’ settings, but the filament settings are a complete mystery. Many Hickok manuals state that the settings were designed to be similar to a simple phone number; easy to remember and consistent. What happened?
Even with all of this mystery surrounding it, I use (and like) my 8-77. It cannot test some of the newer tubes (the 8-77 basically stops at loctal tubes), but I definitely have faith in the readings for any tube I do ask it to test and evaluate. This would make an excellent tester for the antique radio repairman. It’s smaller physical size is a bonus.
Next up, in numerical order, here are a pair of Stark tube testers that defy category. First we’ll visit the Model 9-99, which seems to deviate from the Hickok design even further.
There are many mysteries to this tube tester, and here are few of those questions I have yet to solve.
- The Model 9-99 ‘features’ lever switches, as seen on Eico or Heathkit tube testers.
- The Model 9-99 still uses the red ‘P4’ button (now labeled ‘Press To Read’), but all other buttons (Gas, Line Adjust, etc.) are not used.
- There is a meter shunt (labeled ‘Sensitivity’), but no adjustable bias!
- Lastly, the name is silkscreened as Starkit, as opposed to just plain old Stark. Perhaps these were offered as kits? I have seen other pieces of test equipment labeled Starkit, so perhaps towards the end of their empire Stark offered kit builders these pieces.
The Model 9-99 still seems to be a tube tester that is solidly built, and gives reliable readings.
The Stark Model 10-44 is a very well made tester, and it too has a few mysteries. Check out the photo below.
I think the Stark 10-44 looks a little like the Hickok 6000A, but there are differences. The sockets have definitely been moved around! I have looked over many Hickok tube testers, and cannot see an identical twin to the Stark 10-44. Here are a few strange similarities between the Stark 10-44 and various Hickok testers.
- The SHUNT dial has three red dots stamped into the metal and marked at 3000, 6000, and 15,000 umhos. This is also seen on the Hickok 600 and 800.
- The case is the larger ‘version’, and not the smaller box at all as seen in the aforementioned Hickok 600 and 800. The case to my 10-44 is actually a size in between the 600/800 and the 752.
- The exact location of the tube sockets and hooded bulbs is unlike any Hickok I have seen. Compare the photo above to a Hickok 6000 for the layout of the test buttons and neon bulbs, but look at the socket location! Now look at the socket location on any Hickok. They don’t quite match the 580 or the 752.
I still really like my 10-44. It is fully capable of testing various tube types; oldies like the 83 and newer tubes such as a 6C10 can be tested here without any difficulty. And the test signal is 2VAC, which is a welcomed improvement over the 5VAC common to older Hickok testers. As a side note, the HS 5348-1 setup for octal output tubes like the 6CA7/6L6/6V6/EL34/KT77/KT88 has returned.
Another mystery is the Stark Model 12-22a. Below is a photographic example.
The Model 12-22a looks a lot like many other Hickok tube testers; compare this photo to a Model 6000 or 8000. The layout is very similar, but it now has some extra artwork added. This unit will still test transistors, and all of the push buttons have been returned.
Lastly, I suppose since Hickok supplied the circuit and the parts to build Stark tube testers, it was only a matter of time until Stark started building Hickok tube testers! During the war years, Hickok had neither the time nor the man-power to crank out all of those Military tube testers. The ubiquitous TV-7 was made by everyone; even a German outfit got into the act! The TV-7 was made by no less than fourteen different manufacturers excluding Hickok themselves! Those manufacturers included Coditron, Forway, Polartron, and Supreme. If you are asking yourself just who the heck any of these people are, you are not alone. Below is a Hickok TV-7C, manufactured by Stark.
There are a few quirks to owning any TV-7, yet they still command a lot of respect, and cash, on eBay. For starters, there is the very high 5VAC test signal; too much for certain tubes, driving them into cutoff! Secondly, there is switching to select transconductance scales (labeled ‘Range’). Still, all tubes are read on the same bland ‘0-120’ scale.
There is still a lot to like about owning any Stark tube tester. They are always sturdy, well made, and seem to last forever. I have purchased many Stark tube testers from Flea Markets, and they always seem to work in spite of their sometimes rough external appearance. Many were purchased by the Canadian Government, so they should be around today, and in good condition.