Dave Richards AA7EE

August 14, 2015

A Sproutie is Born in France, to Henri F6GMQ!

Filed under: Amateur Radio,Ham Radio — AA7EE @ 12:10 pm
Tags: , ,

Around the same time I heard from Andy M6YAO that he had finished his Sproutie, I heard from Henri F6GMQ, who was also building a Sproutie and close to completion. A Sproutie in Orsay, in the North of France – how inspiring! To my knowledge, there are now 3 Sprouties in existence – Henri and Andy came in joint second.

Henri built his regen in an old measuring instrument case. He kept the original 12V power supply, for powering the circuit. The variable capacitor came from an old tube radio. He’s already thinking of constructing a second one, in a nice wood or aluminum enclosure. Love those instrument handles!

A view from the back, showing the side braces that help to make the structure more solid. We must be thinking alike Henri, as my most recent version of The Sproutie also has instrument handles and side braces –

Henri’s first coil gives coverage from 5.5 – 7.2MHz. He says he has been able to listen to SSB, CW and broadcast stations and that selectivity and sensitivity are great, considering the relative simplicity of the circuit –

It’s interesting to see how other people build things. It looks as if Henri made his own Manhattan pads. Nice job! He also mentioned that he likes the AF stages of this receiver. Our thanks go to Charles Kitchin N1TEV for that, as they are the AF stages from the regen he described in the Feb 2010 issue of CQ magazine. Henri said that the receiver behaves exactly as I described. I do try to accurately reflect my experiences, so thank you for mentioning that Henri. I don’t think there’s any point in covering things up. If I think there’s a potential issue, I’ll mention it so you, the reader, will know what to expect.

Henri is looking for ideas for a simple 40M VFO, as 40M is his favorite band. He is thinking of building a high performance receiver for 40. If anyone has any ideas, you can leave comments underneath so that Henri will see them. He’ll be very grateful, and interested in all ideas, I’m sure.

Thank you very much for sending your photos Henri. It’s really great seeing how others build things, and it’s really great to know that there are now Sprouties in the US, the UK, and also France. Also, a big thank you to all who were involved in designing the circuit elements that make up this cool little receiver. They include (but are not limited to) GI3XZM, GM4HTU, G3RJT, G3VMU, G4RGN, VK2BHT, G3RJV, and N1TEV.

4 Comments »

  1. Dave,
    Have Henri look at AA3SJ’s web site; he did a 40m receiver based on W7ZOI’s Progressive Receiver.
    73 Walt K3ASW

    Comment by Walt Thomas/K3ASW — August 18, 2015 @ 2:24 am | Reply

  2. Hi Dave
    I have started to get the parts together to build a Sproutie. Do you have any recommendations or changes from your original published design.

    73,

    2E0WSF

    Stephen

    Comment by Stephen — September 2, 2015 @ 10:11 pm | Reply

    • Stephen –

      For a general coverage regen, this design works well. If you want it for SSB/CW use only, it would be worth trying much lower values for the 39pF capacitor that couples the tank circuit to the base of the 2N3904 Q-multiplier transistor. Lower values may well reduce oscillator pulling. You might want to try values of 18pF, or even as low as just 2 or 3pF. This may well reduce oscillator pulling, meaning you can run the RF gain a bit higher. The possible downside is that it may reduce the audio bandwidth, adversely affecting AM reception. Note that if you change this capacitor, it will affect the frequency coverage too, so best to determine what value you want to use before winding a lot of coils.

      If you want to do plenty of AM shortwave broadcast listening, along with a bit of SSB and CW, then go ahead and build it as per the published schematics.

      Incidentally, I am about a month away from publishing details of the Sproutie MKII. The front end is exactly the same, but I wanted to see how a regen would sound with a bank of switched active audio filters. Narrower filters aren’t such a big deal for AM reception, but they are quite beneficial for SSB and CW listening. I have a bank of 6 separate filters, switched with a rotary switch, It greatly increases the circuit complexity though. If this interests you, I hope to get it up on the blog in about a month.

      73 for now, and good luck!

      Dave
      AA7EE

      Comment by AA7EE — September 3, 2015 @ 1:23 am | Reply

      • Hi Dave

        Thanks for coming back to me. It is indeed narrow band CW and SSB reception which interests me so the suggested mods sound like a good idea. I am still in the early stages of acquiring the critical components like the slow motion drive and variable capacitors so I think I will wait to see what your new MKii is like before making any hard and fast choices.

        73,

        E20WSF

        Stephen

        Comment by Stephen — September 3, 2015 @ 12:13 pm


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