DIY Audio Projects Forum

Hi Andrei,

yes,....fine diagrams with several possibilities.
Interesting is also the table with different values of R1/R2 and the different resulting current values.

Cheers
Joe

Hi,
I think for SW, this table is very interesting.
In my experiments with the TA7642, I observe that
the chip needs more energy to SW. Build a structure with two potentiometers (R1 / R2)
to find out the best short-wave application with best results.

Hi again!
Here is another simple diagram that use TA7642 with classic earphones of 22...32ohms.It has two advantages:
I) if you don't have ZN415 or 416 you can use this diagram only with earphones,without any stage of amplify;the condenser make all the job;
II) the diagram has a rezistor of 100K in parallel with the tuning coil and VC so it could improve a little the signal quality in the case of a strength local station.

Here is the description for those who know German:
Das Elektronik-Logbuch
Notizen und Tipps von Burkhard Kainka

5.1.2008 Radiobasteln

Meine Nichte Leonie wollte auch mal ein Radio bauen. Zufällig hatte ich gerade ein Mittelwellen-IC TA7642 (entspricht MK484 bzw. ZN414) bei Conrad bestellt. Mittelwelle ist relativ interessant für Jugendliche, weil am Abend auch ohne lange Antenne viele europäische Sprachen zu hören sind. Das Radio sollte in eine große Tic-Tac-Dose eingebaut werden und ohne Schalter auskommen. Wenn man den Kopfhörer einsteckt, sollte die Versorgung eingeschaltet sein. Deshalb musste der Empfänger ohne zusätzliche Verstärkerstufe auskommen.



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Gegenüber der Standardschaltung haben wir ein paar kleine Änderungen ausprobiert, bis alles optimal funktionierte. Der 1-k-Widerstand im Ausgang reduziert die Verstärkung etwas und sorgt für einen verzerrungsarmen Klang. Beide Seiten eines Stereo-Kopfhörers wurden in Reihe angeschlossen. Die aus einem alten Radio stammende Ferritantenne musste mit einem zusätzlichen 100-k-Widerstand bedämpft werden, um Schwingneigungen der Schaltung zu begegnen. Das IC enthält nämlich eine Entdämpfung, um die Güte kleiner Spulen anzuheben.

source: http://www.b-kainka.de/Weblog/Logbuch080105.html

Good luck!

Hi Andrew,
one more time a new interesting variant of the schematic TA7642/ZN414.
This is a very variable AM- chip. This is a german link, I haven´t never seen before.
Thanks and all the best .
Joe

That's for nothing Joe. I think and also I want to make public or to share my all collections with this diagrams with IC FM or AM from different web sites (japanesse,german,french,english,czeh,bulgarian etc) because seldom the people find them..only if they change the google search to .de . fr .cz .jp .bg etc and also try a google translation or look on a foreign language dictionary for the "radio" (tuner,receiver,radio). If I'll find anothers, I'll post here and also,also I repeat this diagrams ..most of them I posted on theradioboard forum: http://theradioboard.com/rb/viewtopic.php?t=3317 .Here are more people I think and I saw that here are more views. I want more and more people to know the diagrams. I suggest to make here an account. It's a good forum.

Hi,

here's another application for TA7642 / MK484
All Friends of crystal receiver are excited.

The AM- chip is working here in a small housing and is directly pluged into the sockets of the detector. That's a good idea to determine the function of a device and
also to check the frequency. Different old coils can be checked as well.

Look at the pictures in the link.
http://www.jogis-roehrenbude.de/Detekto ... finder.htm

greeting

Joe

A new german diagram of TA7642/MK484 is here with "Lambada Diode".Joe,can you translate me the document?I don't know german and I cannot understand how the schematic works.

Hi,again! Recently I have found an interesting diagram,not tested yet by me. It is what I saw on bob-tech website called "wireless headphones"(an FM transmitter): http://www.bobtech.ro/proiecte/emitatoare-receptoare-fm/14-casti-fara-fir-radio-fm,


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but this is on AM. It uses ZN414 for reception.


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I have made a correction for the radio diagram (in red,compare to the above diagrams).


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In the link is the original document: http://www.sendspace.com/file/c89erp for downloading

Hi again! Here I'll post some new designs for the MK484/ZN414/TA7642 and ZN415.
Hope to join them

Other designs: