04-18-2017, 06:21 PM
Good news and bad news today. I finished checking all the wiring and found and corrected one mistake. So I decided it was time for a test. First I put in all the tubes except the rectifier and gradually cranked up the variac. No sparks, no fire, no problems. So I put the rectifier in and again slowly cranked up the variac. Everything looked good. It drew more current than I expected...about 0.75A. So I don't know if that's bad or not. Also, the panel lamps don't light. They are driven by the filament circuit and since the tubes are lighting up I would expect the bulbs to light up as well. They measure ok, so I don't know what's up there.
EDIT: I think I just figured out the panel lamps. It dawned on me that there is just a single wire to each lamp, so the housing will need to be grounded.
The bad news is that I am getting no audio at all, except a little bit of hum with the volume control turned up past half way. I did not re-install the pushbutton assembly yet because I wanted to make sure I was pretty much done working on the bottom side of the chassis to avoid possible damage to the pushbutton assembly. But now, looking at the schematic, it looks like I need to install them. It looks to me like the phono pushbutton does some pretty important stuff in the circuit. So I'll try installing them later tonight or tomorrow and see what happens.
Also, I have a suggestion for an improvement to the Phorum...where is the proper place to post that?
Rich
EDIT: I think I just figured out the panel lamps. It dawned on me that there is just a single wire to each lamp, so the housing will need to be grounded.
The bad news is that I am getting no audio at all, except a little bit of hum with the volume control turned up past half way. I did not re-install the pushbutton assembly yet because I wanted to make sure I was pretty much done working on the bottom side of the chassis to avoid possible damage to the pushbutton assembly. But now, looking at the schematic, it looks like I need to install them. It looks to me like the phono pushbutton does some pretty important stuff in the circuit. So I'll try installing them later tonight or tomorrow and see what happens.
Also, I have a suggestion for an improvement to the Phorum...where is the proper place to post that?
Rich