ATS-4a Ready to test Now Finished

ATS-4a is now finished and fully operational.  The audio coupling Cap C55 was a problem that I solved by putting an additional .1uf in parallel with the existing cap.  Some folks have suggested swapping C55 and C61.  In any case it seems that C55 needs to be larger in value for the audio chain to provide adequate output.  At this point I am getting about three watts output at 12V with a weak 9V battery in the Oak Hills QRP Wattmeter into a dummy load.

ATS-4 Finished

ATS-4 Top

ATS-4 Bottom

Today the missing (lost) 'Red' SMD Cap came in the mail.  The last component was added and the unit was inspected and looks ready for final assembly and testing.

Quoted from ATS Yahoo Group


Another ATS4A on air.Posted by: "rv3apm1" rv3apm1@yahoo.com   rv3apm1Thu Mar 10, 2011 2:49 am (PST)

Thanks for this group and thanks Steve for nice job.
Now Built my small nice ATS4 A. Good CW tone , Pout 5-6W and only 15 m 4W. Good RX.
Note:
Not used liquid flux for switches, C55 really 1.0 uF, C46 0.01 uf
BS170, 2N7002 careful to do solder - not good for static
73 Serge