Improving A Simple FET Regenerative Receiver - Part One

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  • Опубліковано 22 жов 2024

КОМЕНТАРІ • 60

  • @radiotec76
    @radiotec76 6 місяців тому +7

    I’m a sucker for any regen receiver circuit. I just love to watch these videos.
    In fairness to Charles Kitchen, his circuits were published in QST in the late 1980s when air variable capacitors, though still challenging to find, were far easier to get than today.

    • @justinelliott3529
      @justinelliott3529 6 місяців тому +3

      I have no trouble finding them, they’re just very expensive

    • @dxexplorer
      @dxexplorer  6 місяців тому +2

      Ohh yes I agree on that. I love his circuits for the performance but still keeping them simple. I just wanted to adapt it to "today" but still keep it simple... and make it smaller too hehe. 73, YO6DXE.

    • @dxexplorer
      @dxexplorer  6 місяців тому +3

      They are indeed. Sometimes we may get lucky and find some for cheap... or presents... but not always 😁. 73, YO6DXE.

  • @bobi_lopataru
    @bobi_lopataru 6 місяців тому +2

    Nu ma gandeam ca va iesi video-ul asa de repede! Abia astept urmatoarea parte!

    • @dxexplorer
      @dxexplorer  6 місяців тому

      Azi lucrez deja la urmatorul... poate maine sau Duminica sa-l postez. Inca imi da de cap circuitul... bobina mai exact... ca de obicei 🤣. 73, YO6DXE.

  • @olivierconet7995
    @olivierconet7995 6 місяців тому +2

    I like very much that idea : taking a design and trying to improve it. Waiting for the next video

    • @dxexplorer
      @dxexplorer  6 місяців тому +2

      I hope we improve it 🤣🤣. Working on the second video now. Still a lot of changes to do to get it to work as I wish it would. Let's see what turns out to be. 73, YO6DXE.

  • @acestudioscouk-Ace-G0ACE
    @acestudioscouk-Ace-G0ACE 6 місяців тому +2

    Great video, I will follow this series closely. Thank-you. 👍

    • @dxexplorer
      @dxexplorer  6 місяців тому

      I am still having a little issues with it but I think on Sunday I will post part two. So far I am testing things 😁. 73 and happy weekend, YO6DXE.

  • @davidportch8837
    @davidportch8837 6 місяців тому +1

    Excellent Ciprian ... really enjoying this series. Looking forward to seeing how this progresses...

    • @dxexplorer
      @dxexplorer  6 місяців тому +1

      Working on part two as we speak. I am as curious as you are trust me 😁. Thank you for watching. 73, YO6DXE.

  • @rafaelgcpp
    @rafaelgcpp 6 місяців тому +1

    I'll be following close. I keep planning on building a Kitchin regen with those changes, but postponing it to later...

    • @dxexplorer
      @dxexplorer  6 місяців тому +1

      I also had this one on the list for a very long time. It was about time to build it 😁. 73, YO6DXE.

  • @joewoodchuck3824
    @joewoodchuck3824 4 місяці тому +1

    Small tuning capacitors are still available such as the kind that would be used in commercially made pocket receivers. They're not expensive either.

    • @dxexplorer
      @dxexplorer  4 місяці тому +1

      Yes... those I used for the original version. I don't like them that much though. Very hard to tune and a vernier drive is twice the price of a multiturn potentiometer... sometimes even more expensive ( at least here in Romania). 73, YO6DXE

    • @joewoodchuck3824
      @joewoodchuck3824 4 місяці тому +1

      @@dxexplorer All I can think of is the possibility to use a reduction pulley which was fairly common in older table top receivers. There was even special string sold for it suggesting the need for occasional replacement, though I never needed to do that. Good luck with your eventual solution whatever it may be. N1KHB

    • @dxexplorer
      @dxexplorer  4 місяці тому +1

      @joewoodchuck3824 Thank you so much. Hmmmmn that is not a bad idea at all. I need to try that too. Especially because these capacitors are also cheap. I tried making some reduction drive using little gear wheels from remote controlled cars... but it was taking too long ))). 73, and have an amazing rest of the week, YO6DXE

  • @Chems7308
    @Chems7308 6 місяців тому +1

    Ofcourse, regen is exclusive

    • @dxexplorer
      @dxexplorer  6 місяців тому

      Not always... but I find them special 😁. They remind me of my childhood so it feels good to travel back in time 😁... at least this way. 73, YO6DXE.

  • @tonychristoph1063
    @tonychristoph1063 6 місяців тому +1

    that's a very good way to learn electronic. thank you

    • @dxexplorer
      @dxexplorer  6 місяців тому

      Is how I started... all I had was a box full of junk parts and a multimeter 😁😁. 73, YO6DXE.

  • @kestutisrimkevicius8891
    @kestutisrimkevicius8891 6 місяців тому +1

    Hi, great project and thanks for a video update. Any news and progress made further?

    • @dxexplorer
      @dxexplorer  6 місяців тому

      Hi.. yes I am working on the video right now. I think I will post it this Tuesday. I wanted today but I have some emergencies to take care of so I had no time. 73, YO6DXE.

  • @ssubaihi
    @ssubaihi 5 місяців тому +1

    I loved your Video and Channel and what all about
    from what i can see here , there is some issues regarding FET Transistor biasing ..
    Also the variable capacitor tuning is a little bit rough because it of (5 MHz tuning width) which considered very wide ...
    However i am very anxious to see next episode ...

    • @dxexplorer
      @dxexplorer  5 місяців тому +1

      The tuning part I managed to fix really easy and now it works fantastic. Is just the regen control / transistor biasing combination that are not yet perfect and as I want it to be... but I am working on making final adjustments until I get it to sound as I please so my ears will be happy finally 😁😁. 73, YO6DXE

  • @4L1LAT
    @4L1LAT 6 місяців тому +1

    nice video. i think series gonna be interesting😁. so about the problem. when there is for example 1k ohm resistor in the schematic and voltage is not like it shoud be yeah you need to change it from 1k to 1.5k or 800 ohms or close to 1 k ohm, but when you change 2.7k ohm resistor with 10k and it still does not meet requirments i belive the problem is somwhere else. 7.3k is big jump for such a small change you got here. at max you need to change it from 2k to 4k no more than that.

    • @dxexplorer
      @dxexplorer  6 місяців тому +1

      Usually yes. In this case I had to check other similar circuits just to see what is different and it seems that some ho as high as 27K ... and it seems to be relative to the voltage that I power the circuit with. I am sure there is an entire theory behind but now I don't have the time to study that hahaha. We will see as for sure the circuit will need adjustments in time in order to get it to work as I like to. For now I am not so happy about the regen part as I was with the sputnik where the regen was really smooth and the demodulated CW and SSB signals sounded much better. Testing in progress for now 😁😁. 73, YO6DXE.

  • @DK5ONV
    @DK5ONV 6 місяців тому +1

    Great Job... 💯👍

    • @dxexplorer
      @dxexplorer  6 місяців тому

      Thank you so much. Working now on part two as we speak. 😁🙏. 73, YO6DXE.

  • @mikemullenix6956
    @mikemullenix6956 4 місяці тому +2

    Would you say that the cheap Chinese xdata radio is better than the best regen reciever ?

    • @dxexplorer
      @dxexplorer  4 місяці тому

      I don't know what receiver you are talking about. Do you have a link ? The xdata Chinese receiver I mean. 73, YO6DXE

    • @mikemullenix6956
      @mikemullenix6956 4 місяці тому

      Kg7uqo

  • @abraheom
    @abraheom 6 місяців тому +1

    Good video

    • @dxexplorer
      @dxexplorer  6 місяців тому

      Thank you so much. Hopefully it will get even better towards the end of the mini series 😁. 73, YO6DXE.

  • @RA-Arg
    @RA-Arg 6 місяців тому +2

    Big hug from Argentina. Keep doing videos like this.
    I am really interested in 6 Meters band. What about a little receiver for 6?
    LU8ARM

    • @dxexplorer
      @dxexplorer  6 місяців тому

      I never built one. Good idea... I will put that on the list. 73, YO6DXE.

  • @captmohelsaadany6751
    @captmohelsaadany6751 6 місяців тому +1

    Perfect ❤️❤️❤️

    • @dxexplorer
      @dxexplorer  6 місяців тому

      Let's hope the new one will work... so far not so good ))). 73

    • @captmohelsaadany6751
      @captmohelsaadany6751 6 місяців тому +1

      @@dxexplorer
      god bless you 😍😍🙏

    • @dxexplorer
      @dxexplorer  6 місяців тому

      @captmohelsaadany6751 🙏🙏🙏 you too buddy. 73

  • @oliverfranklypartolesen9882
    @oliverfranklypartolesen9882 6 місяців тому +1

    Are their Activision on that band you play with on this receiver

    • @dxexplorer
      @dxexplorer  6 місяців тому

      Of course yes. Is receiving from 6.5MHz to 14.5MHz so is 3 amateur radio bands available... 40m, 30m and 20m. On 40 you get to listen to DX and local stations... on 30m usually a lot of digital and CW and on 20m mostly DX stations. And of course a lot of AM broadcast stations too.

  • @tovarichiwantankista9412
    @tovarichiwantankista9412 2 місяці тому +1

    What is the thickness of the RF coil wire?

    • @dxexplorer
      @dxexplorer  2 місяці тому +1

      I used 0.35mm or 0.4mm enameled copper wire. This for the new coil version made on a toroid.

    • @tovarichiwantankista9412
      @tovarichiwantankista9412 Місяць тому +1

      ​@@dxexplorer And here we go, I've been trying to make the receiver work. To no avail though. Both air core and toroid, all voltages are OK. Multiple fruitless attempts. Nothing. Sir, if you got a change, could you let me know about your problems with the circuit? That could be helpful, thanks.

    • @dxexplorer
      @dxexplorer  Місяць тому +1

      @tovarichiwantankista9412 the only issues I had was with the FET transistor. I had a few MPF102 that just didn't want to work. Maybe try a few different other JFETs ? The voltages were fine for me too with the MPF102 but the receiver simply didn't want to work. I had the same issue with them on the older VFO circuit that I made in one of the older videos. Not sure if that may be the same problem in your case... but that worked for me. Also I am still trying to improve the biasing of the JFET in this receiver. No matter how I do it... the CW sounds strange on some bands. If I only build it for one band and make the proper adjustments it sounds great... but the way I want it to cover at least 3 bands... no so great. Still work in progress on this part but I had no time because of too much work.

    • @tovarichiwantankista9412
      @tovarichiwantankista9412 Місяць тому +1

      @@dxexplorer Yeah, it could be the JFET... I have recently ordered BF245 and hope for it to work. Anyway, thanks for the reply!

    • @dxexplorer
      @dxexplorer  Місяць тому

      @tovarichiwantankista9412 Always a pleasure my friend. Let me know if it works. And I also have to order a few 😁😁. And I need some J310 as well both to try with this receiver as it seems that it was the original one... and also for the Mini Whip antenna. So far I am not so impressed with the ones I tried, including the MPF102. So I am really curious how it will be with a J310. 73, YO6DXE.

  • @uuid.uuid4
    @uuid.uuid4 6 місяців тому +1

    yay inductive / marginal learning!

    • @dxexplorer
      @dxexplorer  6 місяців тому

      Is what I call "play by ear" 🤣🤣... the way I used to build circuits when I knew nothing about it and had no measurement equipment except a simple multimeter. A lot of trial by error but it works... most of the time 😁. 73, YO6DXE.

  • @romanescu_misha
    @romanescu_misha 6 місяців тому +3

    You are the beginner, and I am Julius Caesar. Makes sense 😊

    • @dxexplorer
      @dxexplorer  6 місяців тому +1

      🤣🤣🤣 but is true... I am still a beginner... I may seem like I know a lot but I don't. I just build a lot and try to learn on the way. I wish I knew a little more... but there is not much time to study unfortunately. 73, YO6DXE.

  • @danielraducu9073
    @danielraducu9073 6 місяців тому +1

    Salut, pentru părțile următoare, te rog da ne detalii și pentru versiunea de 10-11m, 😊😊😊

    • @dxexplorer
      @dxexplorer  6 місяців тому +1

      Haha... o sa te fac sa razi... dar nu o sa dau ))). Ideea este sa experimentezi si sa descoperi singur ))). Da povestim ca e usor de schimbat 😛.

  • @oliverfranklypartolesen9882
    @oliverfranklypartolesen9882 6 місяців тому +1

    I Mean activity

  • @andrewandrosow4797
    @andrewandrosow4797 6 місяців тому +1

    Hello! I made several experiments with super regenerator with two transistors in barrier mode. The results was unsatisfied (I use a part of coil to matching impedance) - only -85dBm. It was an idea to make sensitive super regenerative receiver for 430MHz.

    • @dxexplorer
      @dxexplorer  6 місяців тому

      I never tried regens for VHF / UHF... maybe I have to make one of those too sometime 😁. 73, YO6DXE.

    • @andrewandrosow4797
      @andrewandrosow4797 6 місяців тому +1

      @@dxexplorer In my opinion for the UHF the best solution is a diode ring mixer (with BAT-15 diodes) and low IF AM/FM amplifier (with capacitors as filter) first stage - low noise bjt with, other stages are with capacitor filters) , that can be realized very easy.There also exists an image, but it is the simplest super. As a geterodyne can be used ASK transmitter with PLL. It is the simplest solution.