[RadioSvit]

New video...[Video: https://www.youtube.com/watch?v=pwEwRNVd96Q]

Comparative audio test Philco 37-640x vs RCA 8C-20. Test of two American radio consoles of medium prestige level.
Philco 37-640x, - a 7-tube radio console with a high-frequency amplifier and a two-stroke 3-tube LF amplifier, which works on a 27-centimeter loudspeaker with electromagnetic biasing. This is a unique rationality and efficiency in the quality/number of radio lamps/price ratio. I can't even think of another such effective design.
You will ask - How did they manage it??! It's quite simple, we had to save on the "magic eye", which Philco basically did not use until 1939 and ... on a separate phase inverter cascade ... If in the first case a "shadow indicator" was used and it did not greatly affect the functionality and ergonomics of the device, then the phase inverter of the requested type greatly affected the maximum output power and the level of harmonic distortions. The output power is only 6 watts instead of the expected 10 watts on a 6F6G pair, and the level of harmonics reaches 6 percent or more. Yes, you have to pay for everything...

RCA 8C-20, - an 8-tube radio console with a high-frequency amplifier and a single-cycle two-tube LF amplifier, the load of which is a 30-centimeter loudspeaker, also with electromagnetic biasing. As you know, such speakers are much more sensitive than loudspeakers with permanent magnets, and that is why they are successfully pumped even by weak two-tube single-cycle amplifiers with a power of 4 watts, as in this model. In my opinion, the rationality of the RCA 8C-20 circuitry is significantly inferior to the Philco 37-640x, because even thanks to a larger number of radio tubes, it was not possible to use a more powerful two-stroke amplifier. Even the more prestigious RCA and Zenith models suffer from this shortcoming quite often, even with more lamps - up to 9 inclusive. So maybe this is not a drawback? Judge for yourself and write in the comments ...