Finding Marconi radio schematic model79-c
If it is a 791 instead of a 79, check here:
you may find a similar model.
If it is a Marconiphone,
Although there were some Marconi models that may not be int he Nostalgia Air database for any number of reasons, partly due to the fact Rider usually put them in with the Miscellaneous models.
Other possible sources could be in the various "Shortwave guides" that were published in that era- many included schematics from the manufacturers. Lindsay publishing has reprinted 1936 and 1937, whether they are still available is tough to say, but you can check the listing of what Lindsay publications has on hand at http://www.lindsaybks.com just look for the book list.
My own suggestion- Recap it completely first. Then check the resistors to make sure none are outside of the tolerances- usually 20 percent. From there, tweak the IF;s and the radio should come to life even with weak tubes.
If you are in the UK, or Europe, there should be a few dedicated museums that may have the schematic available as well- just use search engines less used. In other words- forget google or bing- Although google.de or google.it might give you some hits if the radio is not of US manufacture.
Feb 16, 2012 |