IR Remote Control for Shortwave Radios & Scanners

These are restored vintage Tube Testers manufactured by the Precision Apparatus Corporation from the1940s to the 1960s.  I have restored quite a few Precision Tube testers, and I am quite impressed with the craftsmanship and quality in these vintage units.  I really like the old wood cases.

These are all Emission type Tube Testers.  Precision's "Electronamic" design in some models of Tube Testers was an attempt to improve on the basic Emission tube testing principle.

Some of the models included VOM functionality.  Precision called this "Set Analyzing".  I try the best I can to restore the VOM functions in these old testers.  I have come up with modern replacement battery systems so the Ohm Meter functionality will work properly.  It is amazing that the VOM functionality in these old testers is still quite accurate after all these years.

Most of the testers include battery testing functionality.  Batteries are tested with a load resistor and will show the condition of a battery under load.  I generally do not concern myself with this functionality.  The value of having the battery testing feature is not worth the cost and effort to troubleshoot and repair.  Most of the time it works properly anyway.

Some of my tube testers are for sale.  These units include written manuals and updated tube test data.  They have a one-year warranty that does not include burning out of the meter movement.  Tube tester meter movements are very delicate and can be burned out very easily by testing a shorted tube, or from improper test settings.  I find the most common functional failure with these old testers is meter movement burnout.

I will also purchase any Precision Tube tester or parts you may have.  Email me at vintageradio@swl-remotes.com with what you have and I will make an offer.  Let me know if the unit works and what parts are missing.  Include a picture so I can evaluate the unit.

All these tube testers are restored.

Restoring includes:

• Clean all switches and controls with contact cleaner.
• Replace any missing, broken, or incorrect buttons and knobs.
• Replace capacitors.
• Replace out of spec resistors - especially in the tube testing circuitry.
• Replace power cord.
• Replace Elmenco fused plug if missing.
• Verify/replace fuses for proper protection.
• Test and replace neon shorts indicator lamp if necessary.
• Restoration of VOM functionality if possible.  I do not repair or re-calibrate the VOM features.  This functionality is not worth the cost or effort to restore.  Usually a new battery will get the Ohms functionality working.
• Replacement of bad meter movements if possible.  Many of these testers have modern meter movement equivalents.  This is expensive and I try not to do it unless the tester is in really good shape and is worth the expense.  Replacement of a meter movement in a tester with VOM functionality will change the circuitry enough so the VOM features will no longer be accurate.  Tube testing can be recalibrated.
• Calibration using a 6L6 tube of known emission.
• Verify roll chart is working.  I don't try to update the roll chart.  I have printed documentation for all these testers for older and newer tubes that I use when testing tubes.  I don't want to take the time to position the roll chart when I need to test a tube, and I'd prefer not to damage the chart from over use.
• Refinish wood cabinets.  Tube testers were used by radio and TV Repair shops and saw a lot of use.  The wood cabinet finishes are all badly worn, and many have damage to the wood itself.
• Recondition all cabinet hardware.  The cabinet hardware is cleaned and oiled so it will work properly.
• Replace rubber feet.
• Replace handle if missing or broken.

Precision Tube Tester Manuals and Data Charts can be downloaded at Chris's Old Radios.

This is a very nice older model 10-12.  It is in excellent condition.   The meter movement was replaced with a newer meter movement.  The meter indicator is a pointer, rather than a line indicator.  The dial face attached with the same mounting holes.  This kept the unit as original as possible.  I even have the original warranty card for this tester.

This is a very nice newer model 10-12.  The serial number has a “D” prefix character, and you can see the difference in the knobs used on the deck.  The electronics appear to be the same as the older style 10-12s.

Precision 10-xx Solid State Prototype?

Does anyone know anything about this tube tester?

I believe it is a prototype Precision 10-xx that never saw production.  The meter is from a 10-12 tester.  The power supply uses a top hat solid-state rectifier instead of a #80 tube.  I can test tubes on this unit using the test data from a 10-12 tube tester.

The buttons for “W”, “X”, “Y”, and “Z” are individually pushed to make the connections to the tube rather than the lever switches like on the 10-12.  There is a knob that is pulled to clear the pressed buttons.

There is a “Gas” pushbutton that is not connected.  There must have been plans for a gas test in this tube tester.  A compactron tube socket has been added.

I would appreciate any information that anyone has about this tester.  Email me at vintageradio@swl-remotes.com if you know anything about it.

Hickok 750 Tube Tester

This is my "go to" tube tester.  The Hickok 750 is a Mutual Conductance tube tester.  Mutual Conductance tube testers are the best for true vacuum tube performance.  When matching tubes, this is the best type of tester to use.

The meter movement on this tester has been replaced.  The original meter movement developed a mechanical problem.  The needle came unglued from the movement coil.  A quick fix got it going for the short term, but a new replacement movement was installed.

This tube tester is in pretty good shape.  A lot of the old Hickok tube testers were work horses and were used daily.  This resulted in a lot of wear on most of them.  The case on this particular unit is not too badly beat up.  There are a few nicks and scratches; overall the tester is in good condition.

There is no calibration procedure available for the 750, but several other models of Hickok tube testers are very similar and the calibration procedure can be used from these other testers.  I calibrated this tube tester using what information was available.  The shorts testing circuitry was pretty far off.  Most every tube I tested before calibration showed a short.  It now works properly following the calibration.

What I particularly like about this tester is that I can check for overall tube quality and also check Mutual Conductance.

I have found a lot of tubes that will check good on an emission tester will test bad on the 750.

Hickok tube testers command a premium price these days, but overall this 750 is a nice tube tester and well worth the investment.