B&K 500 Tube Tester

dcmeigs
dcmeigs Posts: 708
edited September 2012 in For Sale (FS) Classifieds
I'm selling my B&K 500 tube tester. This tester has new precision resistors on the bias voltage divider and bias voltages are spot on. The selenium rectifiers have been replaced with 1N4007 silicone diodes. The calibration was done last week and checked against my B&K 707.

This model is a quality mutual conductance tester (as opposed to an emissions type). I does both "good-bad" and Gm readings and it's particularly good with power tubes. The gas and grid emissions circuit is very good and the Gm test is considered very accurate.

It is limited in it's small signal dual triode tests because it tests both triodes as one and gives an average reading. As such, it is of no particular help in identifying matched tubes. It does do very well with grid emissions, gas testing and shorts, however. (I'll make the observation that testing for matched triodes is rarely important unless one is dealing with a tube used in a paraphase circuit)

The B&K 500 did not have the ability to test the EL84/6BQ5 type, a huge shortcoming. This unit has been modified to test that type. The attached photo shows this socket.

It comes to you with the original manual, tube charts, schematic and calibration procedure. Calibration pots are labled for your future needs.

The case Tolex, like most, is pretty ratty.

$180 shipped. You might find one on uPay for less, but this one actually works; a major benefit IMO.

I'll be happy to answer any questions.
The world is full of answers, some are right and some are wrong. - Neil Young
Post edited by dcmeigs on

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