Rap 'n Tap
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From: David
Date: 6/18/00
Time: 6:12:21 PM
Remote Name: 216.173.215.110
OK, in Linday's book "How to Build the Twinplex" (back to that again) he says to use a resistor value sufficient to give half the supplied voltage between ground and the collector "with no audio applied". What does that mean? No headphones connected? I used the 68k used in the schematic and the radio works. Just for fun I checked the voltage and it was about 4.50v, not 6v as i was expecting. Stuck in a 47k and got the 6v but the squealing was unbearable. Went back to the 68k. If I measure the voltage without the headphones connected I get 11v. I'm so confused.
Just got a copy of the "1934 Shortwave Radio Manual". Makes me drool and gibber incoherently with excitement. The chapter on using solidstate parts is what piques my interest. Since my radio building seems to be limited to cook-book building I'd sure like to see a book devoted to building these old circuits using transitors. My experience is very limited so I'm really stumbling in the dark when it comes to experimenting. I don't have the patience to start from the ground and make the mistakes and follow the blind alleys that brought radio technology where it is today.