I seldom post to this board, (last time in 2009), but I read it every so often as there are a lot of questions answered already that come up for me. I'll be honest, I'm always intimidated because as a woman, I feel that I am invading the male place. Please forgive me, but I can find no information on the particular questions that I have.
O.K. on to the topic...
I have recently acquired a wonderful old Supreme Model 89D tabletop tube tester. It was in very dirty condition and I have been slowly cleaning it up. I love the skill and pride that went into it. The Bakelite and the old oak case are just gorgeous! The unit is relatively intact, but some 'critter' was able to get into the chassis and chew a couple of components and some insulation from wires. If it was a rodent, it had to be very tiny. Not sure, since no droppings or urine stains are anywhere to be found whatsoever. My dilemma is that one capacitor in particular, a Solar Sealdtite, has been all but obliterated. I have visited Steve Johnson's site and have downloaded the schematic for this tester. What I have found is that the capacitor values are very vague on the schematic. None of them exactly match the caps in my unit. I have also read that Supreme made a lot of changes in production that were not always updated. What I am confused with is that there is no real voltage ratings shown on the schematic. The cap in question is a .01uf between two rotary switch contacts. The schematic says - .01/.1. (lower left corner meter circuit section on schematic). All of the capacitors are shown this way except for the grid cap on the 01A tube, which is another confusing issue as well.
First question: What is the voltage rating and value for the .01 capacitor on the schematic? I am guessing it to be 100 volts (?) judging by the size, but not certain, since there is very little of it left. Is it even supposed to be a .01uf???
2. What is the correct value and voltage rating for the capacitor tied to the grid and plate circuit of the 01A tube? Note "C" says that it was changed to a 40uf from a 50 or 5.0 (?), or is it 4.0 uf? The schematic is very hard to read and leaves a lot to be desired in terms of legible writing! (Some illustrator needed a good penmanship class!
) Note "C" says that it is supposed to be substituted for an electrolytic although the picture does not show it as being polarized???
There are only four capacitors that I have found in this tester and nothing matches what is on the schematic at all!
If someone could tell me what all of the CORRECT values and voltage ratings as well as the direction of polarity of the cap tied to the grid and plate circuit, if in fact it is supposed to be an electrolytic. None of the caps in my tester appear to be electrolytic. This unit "appears" to be all intact with no hacking done by anyone except the little critter that was inside it once.
Caps in my tester are:
2x - .5uf Solar Sealdtite @250v (love the look of those vintage light blue Solar caps!)
1x - a large, very old, wax covered Sprague "600 Line" .5uf @ 600v (gorgeous graphics on it BTW!)
and 1 little, obliterated Solar Sealdtite, of which not I am sure what this value and voltage rating is supposed to be!
The schematic is on Steve Johnson's site if you need to see it. Thanks to Steve for making whatever information is available on these testers available!
I have a couple of other questions but do not want to get in trouble for posting these, since they are different items of the same tester.
Any help would be greatly appreciated. Thanks so much!