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Hi. I heard a lot of people saying that for sound purity you really need to go full tube construction, so, for your superhet it would be interesting to build this tube stereo decoder: www.turneraudio.com.au/am-fm-radio-tuner-multiplex-decoder_files/schem-tuner-multiplex-decoder-05.gif

​@@perianmarcel2059Very involved circuit to build, not worth the trouble. The ICs I used for the stereo decoder and AF amps are high quality, and there is no solid proof that tubes sound better than solid-state, but if they do, the difference is so small it can hardly be detected by human ears 😊 Regards. Camil.

Din pacate nu, la PCF801 catodul e comun pentru trioda si pentoda, in timp ce la PCF82 cei doi catozi sunt independenti. In schema se vede ca trioda are in catod soc de rediofrecventa iar pentoda are grup RC i n catod. Daca PCF82 / ECF82 nu este disponibil, el poate fi inlocuit cu PCF802 / ECF 802 sau chiar cu PCF80 / ECF 80. Echivalentul sovietic al lui ECF80 este 6F1P, care se gaseste usor pe Ebay si relativ ieftin. Performantele nu sunt aceleasi, PCF802 si ECF80 ofera o functionare buna, dar sensibilitatea receptorului e discret mai mica decat cea oferita de PCF82.

2SA268, 2SA269, 2SA352, GT311, 2N1585, GT321, EFT317, EFT319

@@samklazar8995 Have you seen the description text? You have there a link to the schematic...

Thank you, John! Your site is really a rich resource for homebrewers willing to build radio projects. Keep up the good work! 73!

Multumesc. Absolut surprinzator pentru un receptor atat de simplu, superreactie!

Hi! Your comment about pirates amuses me. I think most of us (ham radio operators) started that way. I was a kid and it was during the communist era here in Romania when I have built my first radio transmitter, and, yes, it was illegal and it was in the FM band (the communist countries were using the OIRT band form 65 to 74 MHz). I remember I was waiting the whole day for the Secret Service (Securitatea) to came after me. They never did... A few months later I realized that the power of my transmitter was so low that it did not covered not even a few streets... Once the old analog TV bands are abandoned, there are plenty of unused frequencies, I don't think anyone is bothering to search for pirates as long as they do not disturb commercial or military stations... The components.... well, most of them are basic components that any amateur should have around home. The tubes can be found on Ebay. The transformer is the only component that is a little more difficult to wind, you need 2 voltages: 26.5V AC for the filaments (300mA) and 80-90V AC which will be doubled for the anodic voltage...

Multumesc! Sensibilitatea pare intr-adevar foarte buna (nu am masurat-o exact, nici nu am un generaor capabil sa-mi dea semnale de ordinul catorva uV). In cea ce priveste selectivitatea, se mai aud uneori statii suprapuse... Sunt convins ca ea mai poate fi imbunatatita mult, in principal prin reducerea cuplajului dintre bobine. In unde medii insa, nu mi se pare sa conteze atat de mult, fiind ma putine statii. In unde scurte probabil ca ar fi mai drastic. Poate ca voi avea candva rabdare sa experimentez un receptor cu tuburi care sa foloseasca filtre ceramice pe linia de FI. (CFJ455K de la MuRata de ex sau chiar un banal CFWLB455K ar trebui sa fie superior filtrelor clasice LC...)

@@alexloktionoff6833 No, you need to rewind all the IF transformers. That's why I am providing the infos about turn no and inductance.

@@perianmarcel2059 I see they’re needed to be rewound. But on Aliexpress I can find only complete kits with all components pcb and case. Do you use a cheap only coils kit? Can you help to find it? Thank you in advance

@@alexloktionoff6833 Try this: www.aliexpress.com/item/1005003757706854.html

Thanks for the IF infos, I will try to use a larger screen shield!

Have you watched the movie till it's end? Circuit is at min 24...

I have already adjusted the core inside the input coil, that seems to be the best position....

Hi. You are right, but, for some reason (not just because de-tuninig induced by Al shield) if I try to shield them, the radio stops working....

@@perianmarcel2059 Ah OK!

Tnx!

Thanks, Ian! All the best!

Thank you!

Thank you. Concerning the coils, you could try to print some using a 3D printer with ABS (or PLA if there is no heat source near the coils)

Tnx!

@@hql400 interesting method, can you provide a link to schematics?

But I'm afraid if use auto-transformer the coupling between windings will be higher having sharp cone right in the middle of sound frequency and much lower at the low and high end so sound will be more distorted. Isn't it?

@@alexloktionoff6833 Hello, I did not mean autotransformer-coupling between the stages ! I meant the coupling the next stage on an resonant circuit: here is the autotransformer principle possible as well, if you build a IF-Amp with single resonant-circuits. This can be done, too and it is seen in the shematic above, too, in the demodulator-stage for instance. But if you want to built a bandpass-filter (seen on the left side in the shematic above), you can couple the secondary resonant-circuit with autotransformer (tapped) winding or by splitting the capacity oft the secondary resonant circuit ! Splitting the capacity is more comfortable for homemade-filters And yes, the coupling will be very high, but this is, what you want, because the selectivity is done by the coupling oft the primary and secondary resonant-circuit ! In case oft the single-resonant-circuit there is only the single resonant circuit itself to get selectivity, the coupling oft the next transistor stage has to be with low damping oft the resonant-circuit, like it has to be in the secondary-circiut of an band-pass-filter. - Splitting the capacity is good for homemade IF-Amps, but it is impossible to make IF-Amps for AM/FM together, thats the disadvantage. But today transistors are so damn cheap, I would build 2 seperate IF-Amps if I want AM/FM in one radio together. You asked for circuits, unfortuately the GFGF-schematics are down, but you can find examples in many radio-circuits of the 70's, some brands did this many times in AM-IF-Amps, too, FM was in TBA120-like ICs. I did this C-splitting-thing in Vision-If-Amps with stagged tuning one-resonant-circuits, it work fine. Hope, it helps, greetings

@@alexloktionoff6833 ...addendum: The autotransformer only transformes impedances as well as the splitted capacitor does, I think, I got you wrong a little bit ^^ but its just about that: transforming impedances in consequence of the low-impedance of a transistor circuit. A seperate couple-winding is useful, too, it can be does in series to the BIAS-resistor... But a seperate couple-winding (10...20 turns) directly over the main-winding is magnetical nearly the same like autotransformer-tap...

Am gasit si un Iunosti nefunctional pe net, isi asteapta randul la reconditionare... Cred ca multi dintre pasionatii de electronica au inceput cu astfel de kit-uri, fie de IPRS, fie sovietice. Acum China a preluat stafeta, sunt multe kit-ui chinezesti atractive pentru pasionati. 73!

Nu ai canal și în Romania

Правда! Этот был построен в 1960 году!

That's good; thanks

Da, si eu am facut rost de unul pentru reverse engeneering pe bobinele de FI. Acum sunt pe cale sa replic un receptor Alfa, tot de Tehnoton...

Hello, yes, of course, you can attach a digital frequency meter( with PIC16F628 by ex) to the oscillator coil and you set it to display VFO-IF, that's exactly the received frequency. You can find such project here: www.hamradio.in/projects/multifunctional-frequency-counter

And varicap tuning because i like like voltage controlled tuning more than mechanical one.

Hello and thanks for your comment! Yes, I know the K174UR3 circuit, but I cannot find it, especially now, when Ebay blocked all the russian vendors (I doubt that people selling capacitors and diodes are supporting the war with the earned coins!). So, I will soon test a receiver with an UKW block from an Okean receiver (tuned for FM) and an TBA120U integrated circuit (or an LA1260 if TBA120 does not work) 73 de YO6PMX и пока-пока!

Sir, I am highly honored to receive comment and advice from a living legend in superregenerative receivers field! I have discovered your site about 10 or more years ago, I have built your 12AT7 receiver and it worked like a charm! It was my first superregen radio. I am planning to build your ECF80 version soon. Congrats again for your site and for sharing your schematics, all the best from YO6PMX!

@@perianmarcel2059 I'm glad to know of your success with the 12AT7 receiver, and hope you have good results with the ECF80 as well.