On Monday, July 23, 2018 at 5:43:07 PM UTC-4, wrote:
This radio had an open speaker field coil. I subbed a choke from my junk pile in place of the coil and used a PM magnet speaker. I have no idea what the specs on the OEM field coil were or those of the choke for that matter.. I just grabbed something to try. The choke is about half the size of a baseball if that makes any sense. The choke came out of something God only knows what and how long ago and measures about 40 ohms. The filter, a three section twenty UF, two at 450V and one at 25 volts was replaced at some point and seems to be OK. I mention this because there is a very slight hum out of the speaker and I'm thinking that perhaps the elimination of the hum bucking coil in the OEM speaker is the cause of this. The hum isn't that bad. as soon as you turn the volume up a bit it's really not noticeable but without using another electro dynamic speaker can I do anything about this? I'm also wondering if I sized the choke properly. Does anyone have any thoughts on these two concerns? Thanks, Lenny

Thanks for all the great ideas guys. I did get it going but it needs an alignment particularly on the short wave band. Lenny