Pfanstiehl Model 8 Radio 1925

[micacapacitor]

This tool is useful for repairing circuits

electronicSgenius com

[Shurbovi]

that is realy nice

[HD7100]

I really enjoy watching your radio demo videos. Thanks! Gary

[JPa311979]

What is the reason for 2 audio transformers? Are they both output, different stages or is it one for each speaker coil?

[AllAmericanFiveRadio]

The 2 audio transformers are inter-stage audio coupling. This also insures that all RF is blocked. The horn speaker is connected to the plate of the audio output tube, no transformer.

[pruefziffer]

Oops-...never mind, I just saw the answer below! :-)

[AllAmericanFiveRadio]

No problem! This concept of varying the filament voltage is a very obscure concept in todays world.

[pruefziffer]

Very good documentary on that precious radio, it could be broadcast on TV!

Why are there knobs for the heating voltage for the rf- and audio tubes on the front plate though?

[AllAmericanFiveRadio]

In the 1920s it was very common to control how the vacuum tube functioned by varying the filament voltage, 5VDC. Lower the filament voltage and it lowers the performance of the tube and of course increasing the voltage increases the performance. This worked OK and it also saved on the 6VDC battery that ran the filaments. Thanks.

[joernone]

Rick,

Very nice and interesting piece of radio history. Sounds pretty good, too. I wonder how much folks paid for one of those radios.

Regards,

John

[AllAmericanFiveRadio]

Hey John,

The cost could vary a great deal because most manufacturers offered them with and with out tubes, batteries, antenna, and speaker. So $50 - $90 to $110 would be a good average range.

Regards,

Rick

[Hammondlover2]

What is the purpose of the RF filament adjustment knob? Is it an RF gain knob?

[AllAmericanFiveRadio]

Exactly. On some parts of the band when the filament voltage is to high the RF section will start to oscillate and transmit.

[coolbluelights]

Pfanstiel? that sounds verrrry German! I've always wanted one of these 1920s battery radios. that one is beautiful, especially from the inside! I guess Atwater Kent realized this inner beauty and that's why they made the breadboard radios. it's amazing to me that something so simple with so few components can pick up radio signals, that's why I'm also fascinated with crystal radios..hm I think I want to build another one now!

[AllAmericanFiveRadio]

Lots of Germans in the mid-west. I was raised in a small German town in southern Illinois, Ya. At that time, the 1920s, I thing more owners of these radio wanted to look at and marvel at the insides because all of this technology was new, nothing like it before. I was looking for a light bulb the other day and found a NOS childs crystal radio set made in Germany, made in the 50s I think. I'll do a video on it. Thanks.

[man13preet]

BTW its coooooool

* * * * *

[AllAmericanFiveRadio]

Lol, thanks. Back in the mid20s radio was magic. And it is staggering how many companies where making radios and radio parts and radio kits. It was an amazing expansion of technology to the general public.

[man13preet]

You work with radios?

[AllAmericanFiveRadio]

Yep.

[L0WRYDER]

Verry nice Rick now when the radio was new or even now when you played the radio did you have to open the top for when the tubes got hot. I would like to know if it gets very hot or is just for serviceing the radio

[AllAmericanFiveRadio]

Good question. The 01A does not get very hot. I decided to play it this morning and I just checked the tubes and there actually cool to the tough. The easy access did make it easier to change out tubes. But I'll bit it was used more just to look at them, this magic thing call radio. Thanks.

[Madness832]

Isn't that the same company that made phono styli?

[AllAmericanFiveRadio]

Yes it is, that was another surprise I found when I was reading about this company. Thanks.

[Lockemeister]

Very elegant method of ganging the 2 variable capacitors. The engineer outdid himself.  It was a treat hearing it work.

[AllAmericanFiveRadio]

Thanks. Yes they did, the action of the mechanism is very smooth. There is no binding at all. If you did not look inside you would not guess it is moving two variable capacitors.

[douro20]

It's rather interesting if you look at the history of the company that they started out as an x-ray machine manufacturer, then they made rectifiers for radios, then radios for a short period of time. They lost out big time in the radio industry during the Great Depression then they turned entirely to steel products. The company is still around, they are called Fansteel nowadays.

[AllAmericanFiveRadio]

Thanks. The history is very interest and I just started looking. I searched the web to try and get more information about the Model 8 and found little. But the information about the company is fascinating. I had to just stop reading about the company because I wanted to get the video done. I will get back to it soon.