Radio circuit

I have made this short film in response to requests for the circuit of the one valve radio featured on my channel. Any queries, just ask. J.

Category:

Science & Technology

Tags:

• Radio
• circuit

[LZ2SM]

I hate those two coil regens!They never work no matter how carefuly I make them!Tapped coil feedback always works

[vinylseat]

@LZ2SM Quite agree! They can be pretty poor but it's all down to the 'Q' of the coil. The coil used with this receiver is superb, wound with Litz [multi strand] wire.Try using a lower H.T. voltage, just enough to promote oscillation, this often improves overall smoothness. Coils wound with just a few turns [experiment] will certainly pick up short wave transmissions but they might be easier to tune in if you replace the 500pf tuning capacitor by one of around 200-300pf. J.

[corny49]

i have got a amplifier very much like yours can it be used for guitar .tte valves light up i dont know any thing about it .the valves are 2 el 34. 2ef86. ecc83. gz34 and rsc a10.if any body would like to swap for an valve amp combination for my harmonica playing.i would be intrested. how many watts do you think it is .i found you by accident . would appreciate your knowlege.the cage and knobs are the same as your amp . thank you i live in the uk.

[vinylseat]

@corny49 Hello C. Your valve line up suggests that it is very suitable for use with a guitar, The output from a pair of EL34's should be around 20watts with plenty to spare. Remember that is true power, not the stupid 'music power ' quoted for rubbish amplifiers. You have a very nice amplifier there and it is quite sort after these days and probably worth a tidy sum if it is in good cosmetic condition. They are not difficult to repair but some of the parts, if needed can be expensive. J.

[vinylseat]

Thanks! The coil is easy to wind. Use a short length of water pipe or similar about 15mm in diameter. It is not critical as such. For the medium wave coil wind around 50 turns of wire salvaged from an old light duty motor or similar, [copper wire, enamel or varnish insulated]. You can omit the Long wave coil if you wish. The reaction winding can be wound along side, 20-30 turns should be sufficent. If incresing the reaction capacitor DECREASES the signal, reverse the connections to the coil.

[LZ2SM]

Another question-can it receive cw and ssb?

[LZ2SM]

Great!But I wonder if I use a SW coil will it work well?

[corny49]

thank you for your response to my questions.at least i know a bit about it now .so thanks again. corny49

[chinesefake]

What a nice chap! I would love to build this but fear I would get very frustrated trying to wind the coils. Maybe a kit valve radio would be better for me. Thanks, Nice video.