[Greggshere]

Hi guys, I started working on an old Air King model 4000 today. I bought it on Ebay cheap couple of months ago because I felt sorry for it, as it looked terrible. I figured I would try and save it from a certain death in the trash. The wooden case was painted a nauseating color of green and was peeling off. I decided I would make it beautiful again and give it to my nephew. 

Anyway, I pulled the filthy  chassis out and did the tear down and clean-up. Today I started the recap and resistor check out. Unfortunately it uses two dog bone 500M resistors  and one 300M resistor none of which I have. The highest I go is 15M. I'm not worried about keeping it original, I just want it to look good and function. I re-stuffed the electrolytic capacitor, because it was easier to go that route, but that's it. So the resistors have drifted way off (700 - 840 on the 500M's and 460 on the 300M) and I need to replace them. I'm having a hard time finding these and was wondering if anyone might have some they would sell me and mail me? Any help would be appreciated.  Thanks!

[Ron Ramirez]

I looked at the schematic on Nostalgia Air.

Where they put "50M, 300M and 500M" they mean 50K, 300K & 500K. In other words, 50,000 ohms, 300,000 ohms, and 500,000 ohms respectively.

I don't know why some manufacturers did this. It seems that prior to WWII that there was no standardization of electronic terms when it came to resistors. In this case, they are referring to the Roman numeral M which means 1000. Notice there is a resistor where the "MEG" is written out. R1, can't quite make out its value on the NA schematic but it is written as MEG, not M. Yes...confusing.

Oh, btw, asking for parts is an ad and should be in the Wanted Ads section. Thanks.

[Greggshere]

Thank you Ron for that clarification, I did not know that. I know I have those values
I thought it was weird that they wrote out meg on some and M on the others. I assumed because the ones that had the M were three digits that they shortened the meg.?
I wasn't sure if I should put it in the wanted section or the one I put it in because I was discussing the AirKing and was hoping someone would set me straight because I found it strange that I couldn't find those higher values. Thank you sir.

[Ron Ramirez]

I remember seeing the Roman numeral M on prewar Magnavox schematics which did confuse a then-14 year old Ron in 1974.

This also came up with someone else recently with yet another manufacturer. It is confusing.

[Ron Ramirez]

Now that I think about it, I think it was Jim Fred (the antique radio author who also published Antique Radio Topics back in the 1970s) who set me straight on the Roman numeral M back in the day.

[Greggshere]

Yeah, thanks again, I try to learn as much as I can from you guys. I might be 60 but I feel like that 14 year old when I'm working on these.?

[EdHolland]

I recently encountered this on the service sheets for the 1947 Zenith that is on my bench at the moment. It certainly made me look twice

[Ron Ramirez]

Yes Ed - I remember now. I commented in a similar manner in post #26, page 2, this thread.

(Hey, not bad for someone who was in the cancer center receiving chemo when I commented earlier, now at home with what they call the "pump" getting more chemo.)

[Greggshere]

Hey guys the volume/on-off control is shot on this AirKing. It was dead on all posts with the ohm meter, so I took it apart and found the graphite had separated from the cardboard disk and was in a little pile. Anyway, the schematic shows this is a 500K potentiometer. I have a new 350K combination volume/on-off control. Will this work ok, or what can I expect from it? Will the volume not be as loud, and if so is there a way to compensate it in another way? I'm trying to keep from buying another pot. if possible.

[Ron Ramirez]

The original 500K pot does not have a bass compensation tap, so yes...go ahead and try the 350K. If the 350K control isn't to your liking, you can always contact Mark Oppat about a replacement.

http://www.oldradioparts.net/