06-12-2017, 11:22 AM
(06-11-2017, 02:03 PM)gregb Wrote: Fantastic job Russ! How many hours would you say it took to complete?
Gregb
I don't know. It was certainly, days. But, for sure, much less time than the first one (mine).
While Jeff's radio is on the bench, I have pulled my chassis to make some updates. My chassis had more missing parts(replaced an/or just missing) than Jeff's had. From his I was able to scan the cap boxes and make new replacements of the 4 original ones. Not having to pull all 3 speakers and the power amp makes things WAY easier for testing my chassis.
I also did some measurements on the 45 tubes' voltages and found them running near 400V (plate, against 330V normal) with a 75 volt bias (against 61V normal) but a proper 2.5V filament. The shop's power line transformer has been turned down to 119V. So the voltage is higher most everywhere else. Even with the higher bias, the B+ is too high. I am building two 10ohm 100W line dropping resistors - on heat sinks. My goal is to drop the line to less than 110V.
There are some notable differences between the 2nd run and third run chassis with significant changes not included in the version II schematics (I have never seen a version III schematic).