A really neat way to make coils I saw in, I think it was QST or some other magazine. You get a small diameter PVC pipe from a home improvement store, cut slits in it so you can collapse inward one end of it, and make a piece of scrap wood to go in that end while winding to keep it from collapsing while being wound. You wind the coil on it, and then epoxy over it a couple strips of plastic. Once it cures, you take out the wood, squeeze the PVC pipe to make one end of it decrease in diameter, and slide off the coil. High Q and no form. If your vertical-plastic braces that were epoxied on were made longer than needed that can be then epoxied to a used tube base.
I loved checking out "The Boy's" books from the elementary school library as a young kid in the early '60s. But I never had access to the materials, components, , tools, and thus the skills required to do anything with much of any of this stuff. I don't recall what editions of the books I'd read, but the classic No. 6 dry cells alone didn't really exist any more by the '60s outside of specialty shops. Years later I knew more and could cobble together replacements but by then tubes were all but dead and transistors and even ICs began to reach the experimenter market.
Bob, yes I remember in the early 70's when the solid state projects and kits in the back of the magazines kind of made the old tube projects look hopeless and ancient!
Takes me back to my childhood when trying to build anything radio related was fraught with nothing but problems. Never mind finding the right components, I never had anything to test any of the components I did have to check if they did actually work, and now I see there were issues with the printed circuit diagram. What could ever have gone wrong ? For me it was always everything. Except somehow bit by bit, year by year, small steady progress was made until i one day built a Superhetrodyne receiver and it did work the first time I switched it on. All I have now, some 40 years later, is some photo's of it.
With any of these old projects involving magnet wire and fairly critical inductors you really have to do the math for modern enamel wire vs. the old cotton or silk covered wire they called for.
Depending on the tuning capacitor's max capacitance, the number of turns required to get the right uh value of the coil could vary. The typical 10-365 pf tuning condenser in order to tune from about 530 to 1710 khz would require a coil wound for about 230uh (0.23mh). There are tuning caps that go as high as 450 pf, the number of turns would be less (smaller inductance) to get a similar AM band coverage or vice versa with a smaller tuning cap. Without knowing the number of turns needed, you have to revert to trial and error method. Having a LCR meter handy to measure Inductance and knowing what target mh/uh value you need, can make winding a coil less frustrating.
Amen. Spacing the turns can extend range at the top end somewhat because it lowers the self capacitance. The compromise of the plug in coil size and the large value capacitors make these simple sets poor performers out of the box.
The great thing about these little one tube regen circuits is they really are as simple as they appear, there is no reliance on unmentioned parasitics or whatever to make it work, you can just toss stuff together and it usually runs, especially down at broadcast band.
Why do you not write a book on the different forms of regen receivers. I believe there is enough interest to justify a print book for us hobbyists to want quite badly!
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👍Thanks for video Mike.
This is the episode I was waiting for as I love seeing regen builds. I think I'm due to make another as my last one was during Covid lockdown in 2020.
These simple sets will never be high performance, but they can represent a critical and huge step in a young radio experimenters development.
Thanks Mike, I've enjoyed this series and your project looks great. Excellent job putting all of this together!
Thanks for taking the time to watch the series.
A really neat way to make coils I saw in, I think it was QST or some other magazine. You get a small diameter PVC pipe from a home improvement store, cut slits in it so you can collapse inward one end of it, and make a piece of scrap wood to go in that end while winding to keep it from collapsing while being wound. You wind the coil on it, and then epoxy over it a couple strips of plastic. Once it cures, you take out the wood, squeeze the PVC pipe to make one end of it decrease in diameter, and slide off the coil. High Q and no form. If your vertical-plastic braces that were epoxied on were made longer than needed that can be then epoxied to a used tube base.
Wow that is a mad method of making your own miniductor!
Love it back to bread boarding and the QST varnish 2X4 antenna mast era.
Ah yes the antenna bee with worried neighbors looking on!
I loved checking out "The Boy's" books from the elementary school library as a young kid in the early '60s. But I never had access to the materials, components, , tools, and thus the skills required to do anything with much of any of this stuff. I don't recall what editions of the books I'd read, but the classic No. 6 dry cells alone didn't really exist any more by the '60s outside of specialty shops. Years later I knew more and could cobble together replacements but by then tubes were all but dead and transistors and even ICs began to reach the experimenter market.
Bob, yes I remember in the early 70's when the solid state projects and kits in the back of the magazines kind of made the old tube projects look hopeless and ancient!
Really pleased that you embarked on another build; always nice to see both the work and the tech you put into these!
Does the world really need another regen? Yes - Yes it does!
Takes me back to my childhood when trying to build anything radio related was fraught with nothing but problems. Never mind finding the right components, I never had anything to test any of the components I did have to check if they did actually work, and now I see there were issues with the printed circuit diagram. What could ever have gone wrong ? For me it was always everything. Except somehow bit by bit, year by year, small steady progress was made until i one day built a Superhetrodyne receiver and it did work the first time I switched it on. All I have now, some 40 years later, is some photo's of it.
Same here.I never had some elmers and mentors till much later - but I had access to books and hobby mags and best of all OLD 73 Magazines.
With any of these old projects involving magnet wire and fairly critical inductors you really have to do the math for modern enamel wire vs. the old cotton or silk covered wire they called for.
Yes the DCC and even hookup wire spaces the turns and you end up with less inductance, but extended range at the top compared to close wound enamel.
Depending on the tuning capacitor's max capacitance, the number of turns required to get the right uh value of the coil could vary. The typical 10-365 pf tuning condenser in order to tune from about 530 to 1710 khz would require a coil wound for about 230uh (0.23mh). There are tuning caps that go as high as 450 pf, the number of turns would be less (smaller inductance) to get a similar AM band coverage or vice versa with a smaller tuning cap. Without knowing the number of turns needed, you have to revert to trial and error method. Having a LCR meter handy to measure Inductance and knowing what target mh/uh value you need, can make winding a coil less frustrating.
Amen. Spacing the turns can extend range at the top end somewhat because it lowers the self capacitance. The compromise of the plug in coil size and the large value capacitors make these simple sets poor performers out of the box.
The great thing about these little one tube regen circuits is they really are as simple as they appear, there is no reliance on unmentioned parasitics or whatever to make it work, you can just toss stuff together and it usually runs, especially down at broadcast band.
The actual problem is KEEPING THEM FROM OSCILLATING!
Why do you not write a book on the different forms of regen receivers. I believe there is enough interest to justify a print book for us hobbyists to want quite badly!
Lionell trains, make good fahnestock clips in two sizes
Great tip - The Train Folks need high quality and they pay!
❤😂ESCARGENCY 😂❤
I have really beem enjoying this series Thank you.. Christopher'/va3nth
Thanks for watching Christopher.