Author Topic: Tubes  (Read 2768 times)

19and41

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Re: Tubes
« Reply #15 on: November 29, 2016, 12:25:16 PM »
There is an alternative to the expense of a tube tester for cases where there is not a catastrophic failure of the tube.  Tube socket test adapters allow one to have a tube in circuit and extends it above the chassis with test points to measure the tube in circuit.  most available schematics have operating voltages shown adjacent to their pin locations.  Here is an Ebay search for them. 

http://www.ebay.com/sch/i.html?_odkw=tube+test+adapter&_osacat=0&_from=R40&_trksid=m570.l1313&_nkw=tube+socket+test+adapter&_sacat=0
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke

Ken Doyle

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Re: Tubes
« Reply #16 on: November 29, 2016, 02:52:13 PM »
I like my old Jackson 648 tube tester, but I don't use it very often.  A tube tester is good for pointing out shorts and duds, but the best test for a tube's performance is by taking voltage readings in the circuit where the tube is used.

electra225

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Re: Tubes
« Reply #17 on: November 29, 2016, 08:16:22 PM »
I have a Jackson 648 and a TV-7.  They must have made billions of those old 648's, everybody has one.  Same with TV-t's.  My TV-7 could use a new meter, but it works okay for me.
If it ain't broke, call me.  I can break it....

TC Chris

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Re: Tubes
« Reply #18 on: November 29, 2016, 08:26:48 PM »
I've got two emissions-type testers, nearly dientical:  A  Heathkit that I built, and Knight-kit that I bought at a second-hand store.  They are virtually identical, and probably based on the Jackson device, based on the layout of controls and switches and the rolling tube-data chart.

Chris Campbell