Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Mission Bell Model 19A Car Radio
#6

I agree that it is likely a Franken radio from the manufacturer who likely got a deal on the 57, 58 and 85 tubes. The 85 is a 6.3V duo-diode triode det /1st AF tube. Strange that they are using it instead of a 75 or a 6Q7 as the 85 requires substantial (-10 to -20V) negative grid bias where the 75, 6Q7 or 6SQ7 usually have no added bias, therefore they likely got a deal on them also. The 58 is likely the IF instead of a 78 or 6K7 and the 57 is an "autodyne" convertor (1st detector) instead of the 77 or the better and more stable 6A7 or 6A8 pentagrid convertor. For these 2 2.5V 1A tubes, there is likely a dropping resistor and these tube filaments in series. Using a 0Z4 saves some filament current. According to Radiomuseum, the 0Z4 was released in 1935 and first used in 1936., so this is likely a 1936 model year radio.

The use of autodyne convertors as opposed to pentagrid convertors in car radios of the mid 30s was not uncommon. In fact, Delco used an autodyne 1st detector, using a 6C6 in Cadillac radios for the 1935 model year and a 6J7 for the 1936 model year.

"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
"Let us begin to do good"- St. Francis

Best Regards, 

MrFixr55


Messages In This Thread
Mission Bell Model 19A Car Radio - by Antipodal - 11-07-2024, 08:25 PM
RE: Gilfillan Brothers Car Radio? - by Arran - 11-08-2024, 05:54 AM
RE: Gilfillan Brothers Car Radio? - by Arran - 11-16-2024, 01:24 AM
RE: Gilfillan Brothers Car Radio? - by Antipodal - 11-16-2024, 02:42 AM
RE: Gilfillan Brothers Car Radio? - by Arran - 11-16-2024, 04:12 PM
RE: Gilfillan Brothers Car Radio? - by MrFixr55 - 11-17-2024, 12:22 AM
RE: Gilfillan Brothers Car Radio? - by Joe Rossi - 11-21-2024, 05:01 PM
RE: Gilfillan Brothers Car Radio? - by Antipodal - 11-25-2024, 08:15 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco 42-345 Restoration/Repair
Yes, 57 is an electrolytic cap that should be 12 mfd 400 volts according to the parts list from the Phorum library schem...RodB — 06:01 PM
Philco 42-345 Restoration/Repair
Looks like if I am reading it correctly it looks like the silver capacitor#57 that appears to be a replacement is of a l...osanders0311 — 05:09 PM
Philco model 38 code 121 not receiving signal.
Thanks Arran. Yeah this plastic is pretty thin. It's a little thinner than the original stuff. It kinda reminds me of p...Stormlord5500 — 04:37 PM
Testing a speaker and output transformer Trutone A2-G
The equivalent of one short turn is basically the same as that of a shorted load. If it is the primary's turn, then the ...morzh — 03:53 PM
Testing a speaker and output transformer Trutone A2-G
I've never had an output transformer become shorted, the failure mode is usually an open primary, or in a center tapped ...Arran — 03:52 PM
Philco model 38 code 121 not receiving signal.
As long as the plastic sheeting isn't too thick, I think that the thickness of photographic film would be just about rig...Arran — 03:19 PM
Philco model 38 code 121 not receiving signal.
Well why not! :lol:Stormlord5500 — 03:14 PM
Philco model 38 code 121 not receiving signal.
Good luck next thing you know you will be winding coils just for the fun of it. DavidDavid — 11:29 AM
Testing a speaker and output transformer Trutone A2-G
morzh Short-circuited turns can be considered as a half-dead transformer. But on this case transformer will hot and s...Vlad95 — 11:01 AM
Testing a speaker and output transformer Trutone A2-G
I am not sure how a transformer could be weak. It could be inadequate, but only when you replace the original with somet...morzh — 09:56 AM

[-]
Who's Online
There are currently 2289 online users. [Complete List]
» 3 Member(s) | 2286 Guest(s)
AvatarAvatarAvatar

>