Making progress. Getting really close to bringing it up on the variac. Here's what is completed.
- Cleaned the chassis as best i could and removed all the corrosion that I could. The Krud Kutter was instrumental in removing the corrosion, but I had to mask it off to preserve the stenciling. It's a mixed bag as to the results, but it is after all a survivor. I managed to get all of the corrosion off the original RCA jacks and speaker terminals which was a surprise. That whole exercise was hard work and time consuming. I certainly couldn't afford to have paid a technician to do that.
- Cleaned the faceplate. Some of it was cleaned with brasso and some with glass cleaner. The stenciling is in pretty good shape and the faceplate looks good for starting out as a basket case mess.
- Replaced a knob and some knob brights with thanks to another AK member. Cleaned them with soap and water and shined them with Brasso.
- Replaced two switches with thanks to that other AK member.
- Recapped the whole power supply. Ended up stuffing two of the original caps, but I got a replacement for the cardboard covered C1 thank to that other AK member.
- Recapped all six of the 0.047 coupling caps - four of which were for the output stage.
- Added in the 10 ohm cathode resistors so I can measure the cathode current.
- Added in the 100 ohm screen grid resistors on all 4 output tubes to protect the output tubes from arc'ing that can be caused by the lower Power Supply impedance.
- Replaced both rectifiers.
- Managed to scrounge a full set of tubes that all test good. Some from other units in the queue and some from the big auction site.
- Added in a transient cap across one of the rectifiers to ground. This cap isn't part of the kit version, but is in the factory version. i added it in because the cost was minimal and the piece of mind was worth it.
- Added in an inrush limiter to the primary side of the power supply per general recommendations.
- I've put in a 3A slow blow fuse and a new cap thanks to that other AK member.
I'm going to postpone painting the trannies until I am sure they are ok. No sense painting something that might be bad. I've put the faceplate and knobs back on. Next I'll wax the chassis and put in the tubes. After that it will be time to bring it up on very low voltage to make sure there are no shorts. I'll get a series of small fast blow fuses for the initial power up on the variac. I think I can get an assortment at the local auto parts store. If everything goes well there is a chance that I might have this powered up over the next few days.
I have not touched the DC bias circuits for the control grid yet. I'll take the initial measurements as I bring it up and see how matched the whole system looks and see what kind of current I get at the 10 ohm cathode resistors.
Here are some pics. The little baggie contains some of the parts removed. Not sure why I have them in the bag. I have a habit of keeping that old junk around for a while and then later convince myself it is trash and get rid of it.