Obtained this 7031 unit. Iron and speaker/field coil still good. Wax line caps read 100 ohms, real shocker when touched right. Parts shipping, will see if it comes around. Four position probe with Luciite lighted len in great shape. Someone had put in an 80uf cap for one leg the of the upfront filter cap. Everything else is original and Loctal tubes still test good . Thought I might find an old ham sandwich in the lunchbox, but none to be found.
Hi,
Looks impressive what’s it supposed to do?
Forrest.
It's a low circuit loading, high gain amplifier with speaker - allows to listen in and isolate defective stages, observe gain stages, find noisy parts. The detector probe has one 6AQ6 grid leak tube, the lens rotates for different setting of capacitance or resistance. The output can connect to a multi-meter and possibly a scope. The 7030 was a better looking unit. Most of the caps are wax paper types, but one is a bumble bee paper in oil I think.
That looks like a handy tester I gather the output can be connected to a meter or scope
Seems like a simple useful tester.
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.