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  • #12190
    Gerry O’Hara
    CVRS Member

    I have been asked to fix a Northern Electric console. However, I cannot identify the model as the chassis and cabinet do not have any labels or other identification marks, and the chassis has been modified. This appears to have been a 9-tube chassis from the 1935-1939 period, such as a 911 or 922, but the chassis layout does not match either of those models. One tube socket has been removed close to the front of the main chassis. The tube line-up as received was: 6K7 (RF amp), 6C5 (local oscillator), 6SK7 (IF amp), 6AC5 (AF amp?), 6F6 (output), and 5Y3 (rectifier), with two sockets not having tubes: the mixer (likely a 6A8) and one located between the IF amp and the AF amps. I would expect a 9-tube chassis to have push-pull output, so one of the missing tubes could be a second 6F6 (the 6AC5 being in the wrong socket) This line-up does not match any Northern Electric chassis. The modifications appear extensive and poorly executed and my first look shows that I will likely have to try to revert to an original design. The good news is that the power and IF transformers seem ok. There is no output transformer on the speaker or on the chassis, though holes in the chassis suggest that there may have been one mounted on it at some time. The rear apron of the chassis has also been modified, with a radio/phono switch and a speaker socket, though the latter only has full HT connected to one terminal (the other not connected) – crikey! There is no provision for an eye tube. The tone control has been disconnected completely and the power supply section modified. All suggestions welcome as to what model this used to be(!). Thanks!!

    • This topic was modified 3 months, 3 weeks ago by Gerry O'Hara.
    #12255
    Gerry O’Hara
    CVRS Member

    I have been doing some further research on the Northern Electric console this week. I had a response to my appeal for info from Paul Guibord of the Ottawa Vintage Radio Society (OVRS). It would seem that this set is closest to the ‘Queen Mary’ Model 911 – the cabinet style is very close, but the chassis layout does not match. It was suggested that the chassis could be from an American Bosch model, as it would seam that most 1930’s Northern Electric models were actually designed by Western Electric who shared intellectual property with United American Bosch of Springfield Mass, However, I checked American Bosch’s schematics for this period and could not find a match (though not all had chassis layout diagrams).
    Paul also sent me a link to a website he and Danielle Labelle of the Société Québécoise des Collecteurs de Radios Anciens (SQCRA) put together that provides identification of Northern Electric radios from cabinet styles – very useful! Check it out here: http://web.ncf.ca/ez578/NE_list.htm. Paul also sen me the advert for the ‘Queen Mary’ model attached here.
    The good news is the cabinet cleaned-up really well – so far just a little touch-up and a rub-over and polish with Howards. I still need to remove the speaker grill and check out the fabric and also fill a couple of scratches with wax.

    • This reply was modified 3 months, 2 weeks ago by Gerry O'Hara.
    • This reply was modified 3 months, 2 weeks ago by Gerry O'Hara.
    #12441
    Gerry O’Hara
    CVRS Member

    Just a brief update: I never found what model the chassis was from – close to a Model 911 (as the cabinet would indicate), but not quite… having one fewer tube socket, so maybe a Model 811, though the layout still does not match (nor did any American Bosch models). Anyway, it was in such a state I removed all the old components, except power transformer, RF coils/tuning gang and tube sockets, almost all the old wiring, and rebuilt the circuit based mainly on the Model 811 (same tube line-up), but with some changes per the Model 911 circuit relating to the volume control/tone compensation circuit to best suit components to hand. I had originally left the IF transformers on the chassis, but these proved to cause instability that could not be tamed – changing these out for another pair from a scrap chassis (unknown model) cured that issue. There were some challenges – whoever had worked on the chassis previously had rewired the local oscillator and mixer stages in the RF sub-chassis. When I reverted it back to as per the schematic, I realized that there is an error on both the 811 and 911 schematics – two wires connecting to the local oscillator band change switch have been transposed on the schematic – wiring that was results in a non-functional oscillator (I know, as I built it that way before I realized there was an error!). So far I have the chassis roughly aligned on the Broadcast band, though it is working on the Police and Short Wave bands also. Currently doing some further checks, tidying-up the chassis and then will fully re-align. It sounds good – even with the speaker out of the cabinet – and appears to have good sensitivity. Some photos of the re-built chassis attached.

    #12486
    Bruce Winter
    CVRS Member

    wow, another nice job Gerry to save that basket case chassis.

    #12521
    Gerry O’Hara
    CVRS Member

    Thanks Bruce. While I was doing the work I kept remembering one of my ‘failures’ – a Knight (Allied) chassis at the SPARC museum that Gary wanted me to restore as it had a nice dial and he had worked on the cabinet. Unfortunately, I think it had started life as a farm radio (likely 32 volt with vibrator) that someone had tried to make into a mains powered set, so no schematics matched it and it was in such a poor state, including rust and a persistent and strong mouse pee smell, I eventually had to call it quits… The chassis is still in the Museum somewhere! I am glad the Northern Electric turned out better… Thanks for posting the article on the SPARC website here.

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