I'll second the Jackson 648. I have an older and a later model 648A. Did not know about Vacuum Tube inc doc. It looks like I may have most of the factory data (manuals, test charts, updates) but for the price I think I'll get a copy. Thanks Bob!!!
It's not perfect, but is great for finding known bad apples. 73, Ron WD8SBB --- On Sun, 1/31/10, Robert Ladden <[email protected]> wrote: > From: Robert Ladden <[email protected]> > Subject: Re: [Drakelist] What circa tube tester? > To: [email protected], "Richard Palmer" <[email protected]> > Date: Sunday, January 31, 2010, 11:18 AM > I have had good luck with a Jackson > 648A tester. It is not an expensive Hickok mutual > conductance tester. It uses a "Dynamic" testing circuit and > there is much debate if that is really better than simple > emission testing. But it does have a test I have found > useful. It has a “Life Line Indicator” test which > reduces the filament voltage. It sounds like a gimmick but > it seems to work for me. Just last month I had a weak 12AX7 > in my T-4XC. It tested good in the regular test, but > it was bad in the life test. I replaced the tube and now I > don’t have to turn the gain so high to tune up. That test > has also worked for me with other tubes. > > That life test has also been useful for 6JB6’s. It has > found soft tubes with the life test that otherwise have > tested good. Whether it finds all soft tubes is a question, > but it has proven to be a good screener by finding tubes for > me that have tested to be soft in my T-4XC (I had a box of > unknown tubes). But swapping tubes is by far the best > test but at least I can eliminate the "no chance" ones. > > My Jackson 648A did not come with the 9-pin NOVAR socket > needed for 6JB6’s. I added it myself and it was not hard > to do using the schematic. One advantage for the Jackson 648 > is that Vacuum Tubes Inc. publishes their own manual for it > (I have no connection to this company except as a customer). > > > There is an excellent discussion of tube testers at > http://www.tone-lizard.com/Tube_Testers.html > It is written from an audiophile’s point of view, the > only other group still using tubes. > > 73, > Bob WW3QB > > > --- On Sat, 1/30/10, Richard Palmer <[email protected]> > wrote: > > > From: Richard Palmer <[email protected]> > > Subject: [Drakelist] What circa tube tester? > > To: [email protected] > > Date: Saturday, January 30, 2010, 9:03 PM > > I hope this is not off topic. > > With the use of "vintage" being used for all Drakes > and tube > > testers, many from the 1940's and before, up to the > last > > ones made, it has become impossible for me to > determine what > > will service my early TR-4. > > > > I have spent hours and hours looking up tube testers > by > > type, make and model. I have spent hours squinting at > > pictures trying to count socket pins. I am burnt out > and am > > looking for help in finding just where to look. I have > no > > idea if post WWII testers even test 9 pins, or if all > 7 pins > > are of the same size. > > > > Richard Palmer > > KB8NXO > > > > -- The law, in its majestic equality, forbids the rich > as > > well as the poor to sleep under bridges, to beg in > the > > streets, and to steal bread. - Anatole > > France > > > > > > _______________________________________________ > > Drakelist mailing list > > [email protected] > > http://mailman.zerobeat.net/mailman/listinfo/drakelist > > > > _______________________________________________ > Drakelist mailing list > [email protected] > http://mailman.zerobeat.net/mailman/listinfo/drakelist > _______________________________________________ Drakelist mailing list [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist
