Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => AmpTools/Tech Tips => Topic started by: plexi50 on March 18, 2012, 01:09:54 pm
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I had a friend that found this tester at the fleamarket this morning. Im getting ready to remove the front panel and guts to see what is inside. Not sure about the plug in aspect or how it works. Pretty cool old find. I believe it to be a homemade unit but ya never know
Then again maybe not. High quality work here:
(http://i356.photobucket.com/albums/oo5/plexijtm45/CapTester.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/CTF.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/CLTS.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/CT1.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/CT2.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/CT3.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/CT6.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/CT4.jpg)
(http://i356.photobucket.com/albums/oo5/plexijtm45/CT5.jpg)
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Looks home made to me, or maybe a low production, the graphics say home made to me, high quality work for sure.
but, what does it do???
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but, what does it do???
Not a clue so far. Plugged it in on variac and slowly got up to 120. I cleaned up all the oxide and dusted it off
I think it may be what ive been needing for a long time to test caps and maybe even a signal tester
Not sure. I bet PRR know the answer though
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Wild guesswork: CLT stands for Capacitance-Inductance Tester. 60 cycle AC wall power goes into the old-fashioned AC 2-prong male "receptacle". The component under test is plugged-in to the banana jacks with test leads. The internal resistors & caps are set to produce an audible test tone in the speaker. The momentary SW selects between the internal cap selected, and the unknown cap under test. When the cap under test produces the same frequency tone as the known internal cap, then you know the value of the cap under test.
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Wild alright. I messed with it a bit this morning. It seems i have to figure out the voltages and how this works. After that i got lost and busy. I'll have to double check that again. No speaker tone yet.
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If I ignore the wall-plug input, it looks like a resistor box, a capacitor box, or a speaker (voice-coil or plate transformer).
Not sure why you would combine a utility speaker with R and C boxes.
The apparent AC input is a mystery.
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The more i look at this the more it resembles the Frankenstein Lab. The resistors are the lightning rods. The caps are the fuses for the throw switch and the big caps are Franky and a donor brain :icon_biggrin:
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If I ignore the wall-plug input, it looks like a resistor box, a capacitor box, or a speaker (voice-coil or plate transformer).
Not sure why you would combine a utility speaker with R and C boxes.
The apparent AC input is a mystery.
I too 1st thought it was an R-C substitution box. But note that the banana plugs are connected to caps, which defeats that notion. I'm thinking the speaker is connected to a filament tranny to produce a 60 cycle tone; and that the speaker is the aural equivalent of an eye-tube.
Plexi: maybe you can reverse engineer a schematic.
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since it seems to be DIY, that AC plug doesn't have to be AC mains. especially because it's not a female. it can be there as test points too.
there's a speaker, different caps options and different resistor options. how about a substitution box to try high pass and low pass filters?
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I'll vote for making a schematic too.
since it seems to be DIY, that AC plug doesn't have to be AC mains. especially because it's not a female. it can be there as test points too.
I've seen similar power jacks in the States on portable audio equipment, and old TVs, as well as test equipment like the one pictured here.