This is my first project resurrecting a dead T4x. So far, I have put the new capacitors in the Ac-4, but not tested yet.
I have disassembled the front panel and tried to clean off what I initially perceived to be smoke tar from the front panel. Now, I am not so sure. I may be attacking some clear-coat Drake put over the original paint on the front panel which has yellowed with age. I am through it in many places, and the paint is much brighter underneath, as is the aluminum. So, in for a penny, in for a pound, I will take off the rest of whatever it is. The question is whether I should put a clear-coat back on. Can someone confirm that Drake used a clear lacquer or varnish over their paint? Next, I am going to do the 6146 final conversion. The plate choke has been burned, and maybe soldered upon. (turns have insulation burned off, and a few shorted) I can laboriously rewind the old form with #29 wire which I have in my junk box. (I measured .0115 dia. AWG 29 is .0113) or, I have sourced a substitute solenoid from SSN. It is the same diameter, and the wire is either #29 or 28 gauge. I can take care of the mounting problems. The new winding is about 9/64 longer than the old one, and the cage height will accommodate the length. Does anyone foresee any problems with a little extra inductance in the plate choke? I could also unwind turns to get back to the original length of solenoid. I have tested it with my MFJ 259 up to 160 MHz and did not see any series resonances, and the wire size will handle the plate current. I am considering how to clean the rust pitted chassis. I have used my dremel rust stripper, gently, and I get a nice shiny metal with no pits and gunk. Unfortunately, it will not reach everywhere. I have not been able to convince myself to immerse it in anything. I did read about glass bead blasting. I have the air compressor capacity, and could make a small chamber to blast the chassis. Question: What parts should be removed first? I am thinking the PTO, meter, and the compression trimmers in the transmit chain. The one under chassis will be protected with tape on the inside of the chassis, as will the tube sockets, and slugs in transformers and any pots. (Seal with tape) What have I overlooked? Should I remove the variable tuning capacitors before beginning? OK... my first post, though I have been lurking here a while. 73 NY0Y Raleigh
_______________________________________________ Drakelist mailing list [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist
