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Next project - Philco 7031 Dynamic Tester
#5

Recapped it, replaced all resistors except two carbons (can hear them faint crackle, will replace them too and clean up connections more). Went with IC film caps and Nichicon 10/18 mfd's whereas it has two 10/20 original cans. Went into the probe - what a tight fit. Someone's been there before. Took out some old black tape and put it back in original order, leaving original parts, and cleaned/lubed the rotator selector. Wound the probe with black tape, don't trust the paint. The unit works quite well and am able to trace the model 70. Can hear all kinds of interference here in the basement, strap the probe ground to tip and it gets nearly silent.  I traced the plates of the 70  and can hear the gains and distortions at each. Don't know exactly what kind of detector this probe is, but it seems to be strapped as a lower voltage diode detector, not a grid leak type. I have question, using probe position 2 - 4.7mmf cap, I don't get any radio detection on either side of the antenna coil, I get radio reception at the mixer coil B+ fed primary, no detection on the secondary, radio detection on the first IF primary coil, nothing at the secondary, then detection on both sides of the audio coil, and detection from there to the end. Is this normal of no detection at these points? Edit, I get slight reception of secondary of the mixer coil on position 3 470 mmf probe cap, but it gets a different station. My coil windings probably not right yet. Interesting I can hear the output transformer radio just getting  the probe tip t near it, just like the manual indicates. I haven't put the signal generator through it yet to trace. Nice little unit.


Messages In This Thread
RE: Next project - by Forrest - 12-24-2020, 08:15 AM
RE: Next project - by radio1 - 12-24-2020, 10:04 AM
RE: Next project - by Forrest - 12-27-2020, 09:45 AM
RE: Next project - by radio1 - 12-27-2020, 08:41 PM



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