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In Reply to: RE: TV-7 tube tester line adjustment problem posted by Richard.Sun on July 03, 2012 at 10:00:19
Hi all, I got a Fluke 15B digital meter and a Heathkit IT-17 tube tester from my friend, and did some tests.
(1) 5Y3 and 83 rectifiers are all tested good, so no problem with the tubes.
(2) The resistors are tested good (R124 = 245k Ω, R123 = 1k Ω, and R125 = 1k Ω), but there is a small blue resistor (= 2k Ω) bringing my attention (please see photo1, red circle), as based on the maintenance document (page10, Figure 6), this 2k Ω resistor should not be in line voltage test circuit (by the way, my tester is TV-7/U, not the later models: TV-7B/U or TV-7D/U).
(3) C103 is being replaced by a VISHAY 100uF / 25V capacitor (please see photo2), and the test reading I got for this VISHAY capacitor is: capacity = 2.5 — 10 nF (far larger than 100uF), resistance = 258.4 Ω.
It therefore seems that the problem lies with the filter capacitor (C103), but I still concern about that small blue 2k Ω resistor in line test circuit — should I remove it?
Many thanks,
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