You may be bored by this but it absolutely fascinated me! I find be given the history of how component developed, helps me understand their use and deployment.
The first transistors that I ever bought were GE 2N107s then 2N170 more gain and much more noise. Many germanium transistors died from the purple death, from contaminates sealed in their cases. Nice content. I enjoyed. Ron W4BIN
Thank you for sharing another great video. I added your Base Bias Control method to my own technical notebook. And I like your Transistor & X’tal Tester very much. Thank you!
Great video Mike! Looks like the 'bias'-pot is really more of a necessity no matter what transistor type (Ge-Si) that you would 'commit' to; in fact, I would think that it would still be useful, to compensate for the unit-to-unit variations even for the same part number type. Glad you made and demonstrated the bias-pot. 73...
Yes, the variations and leakage and of course temperature effects cause a gospel solution of popular resistor values to be unrealistic with these old devices.
@@MIKROWAVE1 That’s a great point. I have built book-circuits when I was younger and by the time I got them working ‘something’ was drastically different in either components or layout between the two. Another perfect analogy to me is how wide (read coarse and erratic) are the potentiometer values that are spec’d in projects; I always found myself adding resistors either around or across those pots to ‘slow’ them down! 73...
Very interesting. I like the little XTAL/transistor tester. Added to the growing list of things to build. Could be useful to add a built in XTAL and transistor that may be switched in/out. As well as testing transistors, could be useful for other purposes like grading XTALs for filters.
Really nice video on transistors and their application radios. Especially liked the test set you built. Thanks again for the video and your time. 73s. KG5IF
Good video! They are some folk around, who understand(?) and appreciate that about which you are talking. Also we get to see a nice Hallicrafters SR150 xcvr on your bench!
MK-328 tester works great for testing. resistors, caps, coils, transistors,diodes. I use a hot carrier diode for detector in crystal sets. I suggest a jfet for the regen circuit with a hot carrier diode across source to gate to prevent forward bias of jfet
You remember my father and my uncle the used to do DIY audio electronics, radios, speakers etc. Nice culture exposure that we don't see much nowadays, save for the Arduino et al. in digital arena.
Great point! The tester is quite primitive. I was just playing with a simple triode tube oscillator that was designed to tempt ordinary FT-243 crystals into oscillating on their 3rd overtone.
That is a neat little rig! I love how you can swap the transistors practically on the fly for the best performance on the band you're working. Awesome idea. I want one! Any chance of posting your schematic and parts list?
Check out my Facebook Mikrowave1 Radio Resources page. Lots of good info to support the videos. facebook.com/media/set/?vanity=Mikrowave1&set=a.784450012439591
Nice receiver. Hope you can provide some info on the coil diameters And slug core size you used here. And possibly a detailed video on the final circuit build. I am working on a similar project Thanks.
The Coil is wound on a classic National XR-50 coil form. It is 1/2 inch in Diameter and the winding space is 5/8 inch long. The powdered iron slug is pretty big. If I were winding an air coil, like on a 1-1/4" diameter pill bottle, I would actually start with the same number of turns and grid dip it with a 270 pF cap across it and see how close I am to 40M.
If you are interested, I have a collection of vintage schematics for Ge transistor circuits from the 50's early 60's. I had a good friend at my local radio supply that frequented the old but useful shows and I often bought a lot of his treasure finds. Sadly I do not have the components, but have managed to keep the cut sheets from the kits.
Usual utterly captivating stuff. However, a bit of a puzzle in the transistor list. The 2N3906 is listed as a general purpose, small signal, PNP silicon device and its NPN counter-part the 2N3907. Sorry if I've got the wrong handle on this..I'll check again. Regards G3NBY
One suggestion: Most of the “footnotes” disappear too quickly for me, would love to see them last 3-5x longer so I don’t have to pause or re-watch. Love the content
A oscillator is a class A amplifier. I think all three transistors in your design work as class A. Is this correct? There was a science fair regen receiver with three transistors. Easy to build for beginners with a coil wound on a batterie. The box with the parts doubled as a case. This is a very easy to build circuit with a good manual.
I use a 260 ft square loop in the vertical orientation pulled up into the trees with the top at 80 feet fed with a 1:4 balun. 100 feet of buried coax out to it. it is a quiet antenna that covers shortwave well.
This is a very valuable information for many of us! Thank you very much!
Thanks for watching some of these old time circuit ideas!
Absolutely fantastic! Wow your radio surely delivers a punch. Thanks a lot for rekindling the old fire in me for tweaking ol' vintage radios!
Again..... A Most Excellent video, on radio design, theory and application !!! Thanks !
You may be bored by this but it absolutely fascinated me! I find be given the history of how component developed, helps me understand their use and deployment.
The first transistors that I ever bought were GE 2N107s then 2N170 more gain and much more noise. Many germanium transistors died from the purple death, from contaminates sealed in their cases. Nice content. I enjoyed. Ron W4BIN
Thank you for sharing another great video.
I added your Base Bias Control method to my own technical notebook.
And I like your Transistor & X’tal Tester very much. Thank you!
Very informative! Not boring at all.Love your videos'!Teaching an old dog new tricks'! : )
Germanium. Front end in the Top HF Receiver in my shack. Thank You ! Keep em coming much appreciated.
I'm NOT bored... I'm IMPRESSED at how little I knew about a subject I THOUGHT I knew a lot about. LOL
I found this video VERY interesting!! Thank You!
Great video Mike! Looks like the 'bias'-pot is really more of a necessity no matter what transistor type (Ge-Si) that you would 'commit' to; in fact, I would think that it would still be useful, to compensate for the unit-to-unit variations even for the same part number type. Glad you made and demonstrated the bias-pot. 73...
Yes, the variations and leakage and of course temperature effects cause a gospel solution of popular resistor values to be unrealistic with these old devices.
@@MIKROWAVE1 That’s a great point. I have built book-circuits when I was younger and by the time I got them working ‘something’ was drastically different in either components or layout between the two. Another perfect analogy to me is how wide (read coarse and erratic) are the potentiometer values that are spec’d in projects; I always found myself adding resistors either around or across those pots to ‘slow’ them down! 73...
Very interesting. I like the little XTAL/transistor tester. Added to the growing list of things to build. Could be useful to add a built in XTAL and transistor that may be switched in/out. As well as testing transistors, could be useful for other purposes like grading XTALs for filters.
Not boring at all...thanks for sharing, good stuff! 73 - Dino KL0S
Very cool regen receiver and other gadgets...I enjoyed it.
Really nice video on transistors and their application radios. Especially liked the test set you built. Thanks again for the video and your time. 73s. KG5IF
This is a lost age of early germanium circuits and projects.
Good video! They are some folk around, who understand(?) and appreciate that about which you are talking. Also we get to see a nice Hallicrafters SR150 xcvr on your bench!
Good stuff! And, your SR-150 is beautiful.
Geeez.. I must really be a nerd. :) I enjoyed this video greatly. Very informative.
After seeing this twice I'm still waiting for the boring parts.
MK-328 tester works great for testing. resistors, caps, coils, transistors,diodes.
I use a hot carrier diode for detector in crystal sets.
I suggest a jfet for the regen circuit with a hot carrier diode across source to gate to prevent forward bias of jfet
You remember my father and my uncle the used to do DIY audio electronics, radios, speakers etc. Nice culture exposure that we don't see much nowadays, save for the Arduino et al. in digital arena.
Love 💖 Germanium
The crystal oscillator type tester is suitable for low frequencies (
Great point! The tester is quite primitive. I was just playing with a simple triode tube oscillator that was designed to tempt ordinary FT-243 crystals into oscillating on their 3rd overtone.
MIKROWAVE1 Isn't having a counter a great convenience! ROFL!
That is a neat little rig! I love how you can swap the transistors practically on the fly for the best performance on the band you're working. Awesome idea.
I want one! Any chance of posting your schematic and parts list?
Check out my Facebook Mikrowave1 Radio Resources page. Lots of good info to support the videos. facebook.com/media/set/?vanity=Mikrowave1&set=a.784450012439591
You forgot my "go to" transistor as a kid in the '50s - the Raytheon CK722 ! 73, Ted, W2ZK
You know what they say, Mike. "Anything worth doing is worth _overdoing_ "
Those germanium transistors are unstable like I am.
Do you ever publish these plans for your crystal sets and receivers?
Nice receiver. Hope you can provide some info on the coil diameters And slug core size you used here. And possibly a detailed video on the final circuit build. I am working on a similar project Thanks.
The Coil is wound on a classic National XR-50 coil form. It is 1/2 inch in Diameter and the winding space is 5/8 inch long. The powdered iron slug is pretty big. If I were winding an air coil, like on a 1-1/4" diameter pill bottle, I would actually start with the same number of turns and grid dip it with a 270 pF cap across it and see how close I am to 40M.
I AM NOT BOARD,GOOD INFORMATION GIVEN.
If you are interested, I have a collection of vintage schematics for Ge transistor circuits from the 50's early 60's. I had a good friend at my local radio supply that frequented the old but useful shows and I often bought a lot of his treasure finds. Sadly I do not have the components, but have managed to keep the cut sheets from the kits.
These could be fun to explore in video. Of course GE in itself is an interesting story.
Usual utterly captivating stuff.
However, a bit of a puzzle in the transistor list.
The 2N3906 is listed as a general purpose, small signal, PNP silicon device and its NPN counter-part the 2N3907.
Sorry if I've got the wrong handle on this..I'll check again.
Regards G3NBY
One suggestion: Most of the “footnotes” disappear too quickly for me, would love to see them last 3-5x longer so I don’t have to pause or re-watch. Love the content
A fair and good call, I found the same. The video was great and I wanted a little more time to soak up what you were kindly teaching us.
I have a screen capture app installed on my phone so that I can grab screenshots of circuits that briefly appear on screen.
Memory lane. 😀
Fascinating. Thank you for sharing. 73 ke4drj.
The "Mr Rogers" of Ham Radio!
I don't have a proper Radio Sweater.
germnium transistor still make the best zero bias am detector ...
A oscillator is a class A amplifier. I think all three transistors in your design work as class A. Is this correct?
There was a science fair regen receiver with three transistors. Easy to build for beginners with a coil wound on a batterie. The box with the parts doubled as a case. This is a very easy to build circuit with a good manual.
Yup generally all low signal linear RF amplifiers are biased class A.
What kind of antenna are you using?
I use a 260 ft square loop in the vertical orientation pulled up into the trees with the top at 80 feet fed with a 1:4 balun. 100 feet of buried coax out to it. it is a quiet antenna that covers shortwave well.
Thanks for another great video!
@@MIKROWAVE1 Holy good night... MY trees are only 65' at the highest. You must be in an "interesting" part of the universe! LOL
These old transistors with ft of 400 MHz? I don't think so, more like 2 to 5 MHz.
Nowadays, degen is where everyone seems to be at. and the RDA5800... whole radio with SWbands for $15, made from the finest chinesium on the planet
I think the clue is in the description "bipolar", have you tried feeding it Prozac or something?
This design is 107 years old
Don't blame me - i'm not that old - Ha. The old designs are fun to revisit and attempt with open eyes.
At 24:00 mention ESD. I'm 70; never have blown a transistor or IC !! ESD is over rated!!