Hi all,

Would anyone happen to have access to a schematic for a 1939 Stromberg Carlson D9?

Broadcast only, valve lineup: 6A8G,6U7G,6B6G,6V6G,5Y3G.

I have tried Radio Museum, Kevin Chants site etc with no luck. Radio Museum mentions "Stromberg Carlson Service Bulletin No. D9." but doesn't have a copy. The model "59" schematic looks like it might be close, but with a 6F6G in place of the 6V6G.

Thanks
Andrew

The circuit is in the 1939 AORSM as an AC BC receiver, but as you say has a 6F6, not 6V6. It is possible that someone has substituted a 6V6 which was designed to replace the 6F6, and can require some circuit mods which should be evident if the circuit is right for your radio. https://antiqueradios.com/forums/viewtopic.php?f=19&t=237914 has a discussion on this subject.

I will scan and ask Brad to post it here, but won't be able to scan until tomorrow.

The radio is mentioned here
http://www.hws.org.au/RadioHistory/manufacturers/Stromberg%20Carlson.htm

and here
https://hrsasa.asn.au/downloads/files/aa_radio-models.pdf

but neither place has a lineup. However both have it as an AC BC mantle which agrees with AORSM.
Good luck with the restoration.

Hi STC830,

I'd have to assume the factory valve should be a 6V6 as that is stenciled on the chassis in the valve layout.

The radio museum site lists it as a 6F6, but no supporting doco.
https://www.radiomuseum.org/r/stromberg_d9.html

The print has worn off the glass so I can't confirm what is currently fitted at a glance.

It is a Bakelite mantle using the same style case as a D39 (dual band) and D70 (transformerless) from what I can find. It also has an internal spiral loop antenna.

Thanks for your help.

By 1939 the 6V6G would have been the preferred bottle. The 6F6G is an octal-based 42 and by this stage was "not recommended for new designs"..

You can pick a 6F6 from a 6V6 by looking at the grid post structure on the micas, through the glass. The 6F6 will have 3 normal spiral grids, the suppressor (the one closest to the anode) will be the same as the other two. The 6V6 looks quite different, it has a pair of sheet metal wings for the suppressor - you can spot these poking through the mica.

A 6V6 can always be plugged into a socket wired for a 6V6 and it will work safely, possibly with reduced power output but not so you'd notice. Putting a 6F6 in a 6V6 socket may cause the 6F6 to run a bit hot as it will be under-biassed.

Rereading your post today I think I might have been under the misapprehension that you want the 59 circuit which I have in the 1939 AORSM, as the closest approximation to the D9. I can still scan the 59 if it is wanted.

I have the D9 service manual which I can scan if you like.

A quick comparison between the D9 & 59 show that the circuit is the same or similar. The differences appear to be in the chassis and layout.

STC830 I did find the 59 schematic on Kevin Chants site, but thanks for the offer.

MonochromeTV if you were able to scan the D9 manual it would be much appreciated.

Thanks MonochromeTV,

D9 service manual now available at https://www.kevinchant.com/uploads/7/1/0/8/7108231/stromberg_carlson_d9.pdf

Differences with the 59 circuit are around the speaker connector and tone capacitors, the 59 being a console.

I might have a late model D9, as the service manual still lists a 6F6 not 6V6.