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 Post subject: B&K tube tester
PostPosted: Jun Wed 25, 2003 11:03 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 7
Location: San Pablo, Ca. usa
How close do the bias voltages have to be when adjusting a B&K Dyna Quick 500 model K.<BR>the service manual lists the bias voltages as <BR>13 vdc 7.5 vdc and 2.5 vdc. I can adjust mine to 13/7.8/ and 2.65 I can make this exact by replacing some resistors, but I am unsure if they need to be exact. I have already replaced all the resistors with new 5% the old ones were 20%. Also I am trying to locate an instruction manual for a Dyna Quick 650 so that I can adjust it but I can't locate one.<P>------------------<BR>


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 Post subject: B&K tube tester
PostPosted: Jun Thu 26, 2003 6:46 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 446
Location: Winnipeg, Manitoba, CANADA
Unfortunately, I have both testers, and both manuals. The unfortunate part? Neither list calibration procedures. I just try and 'fake' it, with the manuals from my other B&K testers. If the readings all seem to agree with one another, I'm happy. They do not have to be within .000001% of each other to allow me to button up the chassis, but 'close enough'. <BR>Here is something to consider. Those voltages were written out when someone measured them with a 20,000 ohms-per-volt meter. Chances are your Fluke is a little more accurate, so your readings should be higher. Those testers are fun to play with, but I decided years ago to stop losing sleep over how well I could calibrate them. What I would suggest is downloading the 707 manual, and do what you can with that. <P>------------------<BR>


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 Post subject: B&K tube tester
PostPosted: Jun Thu 26, 2003 8:28 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 30698
Location: Pocasset, Cape Cod, MA
If the original resistors were 20%, then the bias voltages weren't tightly controlled anyway. I wouldn't worry.<P>The 650 as I recall is an emission tester. There's a simultaneous discussion going on here about calibrating emission testers, and the general answer is to make a guess.<P>------------------<BR>


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 Post subject: B&K tube tester
PostPosted: Jun Fri 27, 2003 4:42 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 446
Location: Winnipeg, Manitoba, CANADA
The 650 ain't no wussy emission tester. Sorry about that; I had to say it. <BR>Anyway, it is as close to the 'K-Car chassis' as B&K gets, and is similar to the 500/550/700/707. The 6AT6 does the grid emission test, and it has three positions of the the four-position switch to test up to three sections of a tube. It also tests transistors. The 650 is the only B&K tester I have that has two listings for the Sensitivity control; one for 'True gm', and one for 'Standard gm'. Even with the manual, I cannot figure out the difference. <P>------------------<BR>


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