telefunken: output transformer primary tap, Concertino 8
? telefunken: output transformer primary tap, Concertino 8
Hi there,I have been working on my Concerino 8 again recently, and studying the circuit diagram I notice (if I am interpreting it correctly) that the main power supply goes to a tap on the primary of the output transformer and then feeds the rest of the set and EL84 screen grid through a 1k resistor. what is the purpose of the power supply going through the output transformer? Leads 2 and 3 on the output transformer seem to be shorted out ( 0 ohms as opposed to 10 ohms DC on the replacement transformer I obtained) . What effect would that have? Also there seems to be zero difference between the screen grid and anode voltages on the EL84. Woukd that be related?I realise now that may be caused by la k of current draw through the rest of the set ( ?) Any info / advice appreciated thanks
To thank the Author because you find the post helpful or well done.
telefunken: output transformer primary tap, Concertino 8
Hello Mr. Matousek,
due to feeding the anode voltage to the tap the current floats through the primary in opposite directions so the hum is canceled out (ideally) for the speaker. Also that part of the transformer works like a choke for the rest of the set so hum is even more reduced. Shorting it out will increase the hum.
Kind regards,
D. Consales
To thank the Author because you find the post helpful or well done.
telefunken: output transformer primary tap, Concertino 8
You can find more information in english language here.
To thank the Author because you find the post helpful or well done.