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 Post subject: Seco 107b Tube Tester
PostPosted: Apr Tue 20, 2004 12:26 pm 
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Location: los angeles, california, usa
Does anyone know the proceedure for calibrating a Seco 107b Tube Tester?<P>Thanks<P><P>------------------<BR>Donald R. Resor<BR>TW&TCSvcCo


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 Post subject: Seco 107b Tube Tester
PostPosted: Apr Sun 25, 2004 10:08 am 
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Location: Warwick,RI
Well,nobody else has answered,so I will take a shot here.It is evidently a mutual conductance type,so probably has several internal adjustments and tube tester calibration information is tough to come by<BR>in most cases.<BR>Easyrider8 may have worked on one;Chris might have also.You might try direct e-mails to these people,or Alan Douglas might have something on it as he is much into tube tester history.But,presumably one of the above would have answered your post already if he could help.Still,might be worth trying to contact them.<BR>Malcolm<P><BR>------------------<BR>


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 Post subject: Seco 107b Tube Tester
PostPosted: Apr Sun 25, 2004 3:56 pm 
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Location: Pocasset, Cape Cod, MA
No, I kept out of this for a reason. Secos are funny testers: they work well enough, but their readings aren't comparable with those of other testers, or with tube-manual specs. For instance when testing a 6L6, the plate voltage sags to only 12V.<P>------------------<BR>


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 Post subject: Seco 107b Tube Tester
PostPosted: Apr Sun 25, 2004 5:48 pm 
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I have a Seco 107 (not A or B). I installed a trimmer pot that let me vary where the LINE ADJUST centered the meter. Having no other calibration reference, I tweaked this pot until the tubes I normally use gave similar readings on the 107 and my Hickok 6000. Most tubes were surprisingly close, although a few weren't. Fortunately I didn't have a 6L6 to destroy my illusions!<P>Brian<BR>


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 Post subject: Seco 107b Tube Tester
PostPosted: Apr Mon 26, 2004 4:58 am 
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Location: los angeles, california, usa
The Seco 107B which I have, has an aging adjustment for the internal vacuum tube which is reachable through the compactron pin straightener with a regular screw driver. This is covered in the operator's manual. There is also a line adjustment for AC on this unit. As for the other 3 pots on the PC board there is no information as to what they are for or how to adjust them. Oddly when I was replaceing all of the components, resistors, diodes and capacitors I noted that there were mica caps on the DMC switch which are not shown in the schematic. They looked original and when I replaced them I upped them to silver mica along with the ceramic capacitor on the 'gas test' button. Other than that and cleaning of the harness plugs with DeOxit it's been very reliable, how accurate it is at this point I am not 100% sure.<P>------------------<BR>Donald R. Resor<BR>TW&TCSvcCo


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 Post subject: Seco 107b Tube Tester
PostPosted: Apr Mon 26, 2004 5:34 am 
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Location: Pocasset, Cape Cod, MA
The actual circuitry in my 107 has only a passing resemblance to the schematic in the manual.<P>------------------<BR>


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 Post subject: Seco 107b Tube Tester
PostPosted: Apr Tue 27, 2004 1:48 am 
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Location: Warwick,RI
tubesrgood wrote:
<font>quote:</font><HR>Originally posted by Alan Douglas:<BR><B>The actual circuitry in my 107 has only a passing resemblance to the schematic in the manual.<P></B><HR>
<BR>That's the kind of senseless thing on the part of tube tester manufacturers that helps keep the headache pill industry going full force.An injustice to any person buying that machine and a damn shame.<BR>Malcolm<P><P>------------------<BR>


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