Its a 15 H choke. the manual is here
http://bama.edebris.com/manuals/I have a Ranger 2; the schizmatic for the pwr supply section is the same. Anything about the same physical size rated for roughly 400 volts should work.......
Dont know how much/far you've got into this thing,or want to, so MY MINIMUN Operational and SAFETY recomendations are..
R3, the famous 18K "chernoble " resistor.. replace with at 10 watt, 18K... most people move it outside the vfo box; you can if u want to
the LV filter cap.. 30uF.. fatten it up.. a 100uF 450V makes a nice replacement; whatever u have bigger than the 30 will be better than whats in there now. The HV cap 10uF, its a joke, two 100uF 450V in series w/ bleeders will give you a nice improvement. The C90A/B kluge can be looked at and replaced.
Replace the pwr cord with a 3 prong; get rid of the fuse block thing and install a fuse in the hot side. You can use an inline fuse holder if you dont want to put in a panel mount in the back...
Check out the AM Window site for the TimTron modifications and a lot more background info for this spaceheater... klc