开云体育

?I see how you are injecting the audio into the mike jack and understand about the DPDT to use the mike or the key... But, how are you doing the PTT switching?

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Try the above circuit , it works , the signal seems clean and it is small . I have not tried it on 40M yet as I am converting a BITX40v3 to 80 M . Tested it tonight , I get full output on CW on 80 M . I have the AF adjusted to approx 1k audio note via the 20 k pot . I am also going to put an adjustment pot in the sine wave output so as not to overdrive the TX . MODS : I changed the 2 - .003 uf to .002 as that is all I had in my junk box . Since I am running 12 V input , I changed the 6.8 k to 10 k ?and it still works on the bench hooked up to the BITX. The circuit is stupidly simple and seems very stable. I just installed the key in series with the sine wave output to the mic connection . Going to install a DPDT switch to disconnect mike and connect audio generator for CW . Simple and it works . 73s Buzz