Wilcox-Gay Recordio 6B30

[mcetilia]

Hi all,
I have been lurking on here for a while, and finally got my hands on a Recordio
that seems to be in good physical condition, but it isn't making any sound
(although the platter spins smoothly).

It may be as simple as replacing a tube or something, but I was wondering if
anyone has any pointers on what might be involved in getting it up & running?
I'd love to try my hand at cutting some records so any advice is more than welcome…

Cheers,
Mark

[Lima Victor]

Looks like a 1940s piece of equipment to me. Replacement of all paper-wax capacitors is almost always needed. Usually all electrolytics too, though sometimes and with lots of patience the oxide dielectrum can be restored. Tubes are usually still good, although the rectifier and power amp tubes may have suffered from powering it up with bad caps.

Never power up tube electronics without checking for bad capacitors first. A shorted out electrolytic cap in the power supply can severely damage the rectifier tube and power transformer. A leaky cap might vent and spew acid all over the chassis.

[mcetilia]

Thanks for the info—it is indeed from the 40s (1942 I believe).
I managed to find a copy of the "Photofact Folder" for the 6B10, 6B20, 6B30 & 6B32
on eBay (can scan it & post if anyone else is interested?) which has a schematic & parts list,
including all capacitor values, so I'll get on Digikey or Mouser or what have you and start swapping those out…

Anything specific I should know?
Tolerances, etc.?

Cheers,
Mark

[Lima Victor]

Tolerance isn't of much importance when replacing paper capacitors, they usually were either 10% or 20%. Be sure to buy caps with the right voltage rating. The rating on the old capacitors may be a test voltage and not a working voltage rating, you probably don't need expensive 1000v capacitors like i find sometimes in old equipment.

Usually 400v capacitors are sufficient, although i've measured peak voltages of 450v in some powerful radios when powering up. In that case, i use 450v electrolytics and 630v caps for the rest of the circuit. Good capacitor manufacturers usually specify allowed peak voltages in their datasheets.

If there's a capacitor between the mains and the chassis, use a class Y2 (or equivalent) capacitor. Those things are designed to be safe when they fail - so no mains will ever be present on the chassis, even at the end of the capacitor's life.