Home » Audio » Radio » Help with identification - Emerson
Re: Type 43 tubes and others [message #25589 is a reply to message #25588] Mon, 27 September 2004 05:53 Go to previous messageGo to previous message
Wayne Parham is currently offline  Wayne Parham
Messages: 18758
Registered: January 2001
Illuminati (33rd Degree)
That's a great looking radio you have there. It looks like someone has rebuilt it in the last decade or so too. The capacitors look pretty new. If that's the case, I expect this radio will work for several decades. You might have to replace a tube or two if you use it often, but the passive components will probably last decades.

To answer your questions, those little rectangular parts are capacitors, you're right. They are small value caps, and would probably be ceramic caps if replaced today. The two coils you're referring to are intermediate frequency (IF) coils. They, along with those caps, resonate at an intermediate frequency.

Your radio uses a superhetrodyne circuit, which is the most modern type and uses IF amplification stages. The Superhetrodyne receiver circuit was invented in 1918 and most radios were made that way from about the 1930's on. In a superhetrodyne radio, the RF signal is converted to an intermediate frequency for most stages of amplification. That way the IF amps can be tuned to a specific frequency and optimized for it. The RF section has to be wideband, since it has a tuner and covers a large frequency range. So amplification is not as efficient as the IF stages, which operate at a single frequency. The IF stages are where most of the gain is done, and then the IF detector converts it to audio for the final audio amplification stage.

 
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Previous Topic: Crosley tube radio
Next Topic: Hi Wayne
Goto Forum:
  


Current Time: Thu Sep 12 14:25:57 CDT 2024

Sponsoring Organizations

DIY Audio Projects
DIY Audio Projects
OddWatt Audio
OddWatt Audio
Pi Speakers
Pi Speakers
Prosound Shootout
Prosound Shootout
Miller Audio
Miller Audio
Tubes For Amps
TubesForAmps.com

Lone Star Audiofest