05-26-2023, 03:07 PM
On-duty Friday video ... I wish everyone a good mood from watching 
Old Philco 37-640x tube radio console. USA 1936//Old Philco 37-640x tube radio console. USA 1936
For a long time I was going to make a video about one very interesting device - the American radio console Philco 37.640 of 1936.
What is so interesting about this device? I will try to take my time to tell about all its advantages and possibly some disadvantages.
Let's start with the design ... Like most models of the Filko company, its design is quite simple, nothing special stands out against the background of competitors, but at the same time it is specific and always recognizable - radio receivers of this company are quite difficult to confuse with radio receivers of other manufacturers.
The quality of the cases was very high, for their manufacture, high-quality veneers of several types were used, mainly American walnut, and decorative overlays made of solid expensive wood types were used quite often. Sometimes even decorative hand-carved figurines. But since this is almost a budget model, the design was done without exclusivity.
In the season of the thirty-seventh model year, which began in the summer of the thirty-sixth year, Philco's hallmark was the round frame of the scale, which replaced the oval-shaped scale of the 35/36 models.
But the most interesting thing is hidden in the middle of the radio, in the chassis, and by our standards it is definitely not for a budget radio. What exactly ? Let's see... In my many years of antique radio fun, I have yet to come across any other seven-tube radio receiver with a powerful three-tube two-stroke audio frequency amplifier and a high-frequency amplifier with a balanced input, and also with a fine tuning indicator.
How is this even possible with only seven radio lamps??? For such a cascade configuration, there should be at least nine of them!
Everything is ingeniously simple - by applying a clever scheme of a combined phase inverter on one of the two radio tubes of the output stage, it was possible to save one radio tube and make a sound amplifier with only three radio tubes. Compared to a standard two-stroke, this type of amplifier has slightly worse characteristics and lower power, but 6...7 watts is always better than 4.
And let's not forget that this is still a budget. For the same reason, only a ten-inch loudspeaker with electric magnetization is installed here instead of a twelve-inch one, which slightly reduced the sound quality.
The second trick made it possible to save on one more radio lamp, we are talking about the so-called shade meter, a "shadow" indicator that replaced the "green eye" radio lamp of the optical setting indicator.
Well, such a masterpiece of circuitry as a high-frequency amplifier with a symmetrical balanced input puts this radio console two steps above its competitors. Let me explain - this technical solution allows you to dramatically reduce the level of interference in the radio airwaves and thereby significantly improve the quality of radio reception. Let me remind you that radio interference on the air is the biggest disadvantage of all radio receivers when receiving medium and long waves.
And here I sprinkle ashes on my head - for 8 years of owning this unique device, I have never built a suitable balanced antenna for it with symmetrical reduction... But when I do, I will definitely make a separate video, because it should be worth it...
So, let's get acquainted with this device on video and evaluate its reception on short waves from a conventional antenna.
[Video: https://www.youtube.com/watch?v=lCRqx9uDw9s&t=153s]
Old Philco 37-640x tube radio console. USA 1936//Old Philco 37-640x tube radio console. USA 1936
For a long time I was going to make a video about one very interesting device - the American radio console Philco 37.640 of 1936.
What is so interesting about this device? I will try to take my time to tell about all its advantages and possibly some disadvantages.
Let's start with the design ... Like most models of the Filko company, its design is quite simple, nothing special stands out against the background of competitors, but at the same time it is specific and always recognizable - radio receivers of this company are quite difficult to confuse with radio receivers of other manufacturers.
The quality of the cases was very high, for their manufacture, high-quality veneers of several types were used, mainly American walnut, and decorative overlays made of solid expensive wood types were used quite often. Sometimes even decorative hand-carved figurines. But since this is almost a budget model, the design was done without exclusivity.
In the season of the thirty-seventh model year, which began in the summer of the thirty-sixth year, Philco's hallmark was the round frame of the scale, which replaced the oval-shaped scale of the 35/36 models.
But the most interesting thing is hidden in the middle of the radio, in the chassis, and by our standards it is definitely not for a budget radio. What exactly ? Let's see... In my many years of antique radio fun, I have yet to come across any other seven-tube radio receiver with a powerful three-tube two-stroke audio frequency amplifier and a high-frequency amplifier with a balanced input, and also with a fine tuning indicator.
How is this even possible with only seven radio lamps??? For such a cascade configuration, there should be at least nine of them!
Everything is ingeniously simple - by applying a clever scheme of a combined phase inverter on one of the two radio tubes of the output stage, it was possible to save one radio tube and make a sound amplifier with only three radio tubes. Compared to a standard two-stroke, this type of amplifier has slightly worse characteristics and lower power, but 6...7 watts is always better than 4.
And let's not forget that this is still a budget. For the same reason, only a ten-inch loudspeaker with electric magnetization is installed here instead of a twelve-inch one, which slightly reduced the sound quality.
The second trick made it possible to save on one more radio lamp, we are talking about the so-called shade meter, a "shadow" indicator that replaced the "green eye" radio lamp of the optical setting indicator.
Well, such a masterpiece of circuitry as a high-frequency amplifier with a symmetrical balanced input puts this radio console two steps above its competitors. Let me explain - this technical solution allows you to dramatically reduce the level of interference in the radio airwaves and thereby significantly improve the quality of radio reception. Let me remind you that radio interference on the air is the biggest disadvantage of all radio receivers when receiving medium and long waves.
And here I sprinkle ashes on my head - for 8 years of owning this unique device, I have never built a suitable balanced antenna for it with symmetrical reduction... But when I do, I will definitely make a separate video, because it should be worth it...
So, let's get acquainted with this device on video and evaluate its reception on short waves from a conventional antenna.
[Video: https://www.youtube.com/watch?v=lCRqx9uDw9s&t=153s]
Old Tube Radio Online Museum / Музей ретро радіо
https://www.youtube.com/user/RadioSvit?d...lymer=true
Sincerely Peter
З повагою Петро
