This is an authentic early 30's Regenerative Receiver that is designed for Portable Ham Radio Operation on Batteries. Let's try to figure it out and operate it.
Mike! I'm really glad you decided to do a video on this diamond in the rough. Very interesting...like a large percentage of your video topics! I wonder if the original maker/owner was a...DX hound. (sorry) Many thanks!
Actually the type 30 was made i 3 formats. The very first version may have been the tubular "T" envelope, most dry battery tubes (such as the 199) were first made in the form. Then they switched to the "S" or spherical / globula type you showed, and finally to the "ST" bulb. In the '50's, they even switched back to the "T" or "GT" format again! The original "Twin Plex" circuit was from the 1930's. It was actually the same circuit as the dual type 30, but it used a twin triode type 19. I built one of these.
I wonder if there might some advantages in some of these older forgotten circuits. Maybe not but still I do not think a anything beats a real working example. I have a huge respect for the radiomen of the era.
How in the world did the maker of this little gem get his big fat ham radio hands in that itty bitty box? Can the sides come off or something?? How did he solder anything with one of those irons big as a popsickle in there??? Love it. Make it work! 73 K4UIE
In this schematic at 10.23 I do not understand the filament voltage on the second (output) tube ! It seems to have no voltage to light the filament. Your schematic later on does, but this looks like an original photo??? There is 45 volts across the filament to plate, but no apparent source of filament voltage?
@@MIKROWAVE1 You are doing a real good job. It looks like it is a lot of work to produce one of those every week! Is there someone helping you with editing etc.?
Ah, a cliff hanger. Very appropriate for something from the 30s, much like the serials back then. Will Captain Mike regenerate the regen? Or will those old capacitors blow higher than Vesuvius? Tune in next week to find out!
The Vacuum tubes made to operate of 12V Heater supply and a B+ of 12V might also work well,you know the ones made in 1957 for use in Car Radios when the transistors of the day were not ready for prime time so should work of 4xPJ996 batteries.
Of course battery tubes are more efficient than space charge tubes because the space charge tubes require a very hot cathode. 120 mW compared to 1.8 Watts per tube.
Regen receiver is a freqency depended negative resistance converter. Negative resistance in antenna make "black hole" for radio waves. ( very sensitive reception ). Antenna transmitts negative resistance to enviroment thinks ( house walls, tree's ground... ) and "attract radiowaves".
The technique does block RF so it adds to the decoupling possibly improving the RF bypassing (throttle capacitor) thus possibly helping stabilize the feedback.
What about replicating that radio using that flat vacuum tube with the 1.5V heater and A B+ of 45V might be a bit microphonic but that cannot be helped and don't generate much heat but it makes me wonder how the manufacturer uses them in in their pedals
Mike, what does thrill box mean? You used the term about a minute in distinguishing the radio as an amateur band radio, not broadcast or shortwave or thrill box.
The National Company made a small regenerative receiver with plug in coils designed in the late 20's during the depression, called the SW-3. Versions were made or 2 and 6 VDC. It used two tetrodes, an RF and Regen and a triode Audio stage. It covered from the BCB to 15 meters in 4 coil sets. This was a capable ham receiver for many, but was coined the Thrill Box by Shortwave Listeners.
