In message <[email protected]>, Attila Kinali w rites: >On Sun, 18 Mar 2012 13:25:54 +0000
>> Not in my implementation, I have eliminated the input capacitor because >> the active element is 3cm from the PCB, > >Could you explain how the distance of the antenna to the PCB is related >to a DC block capacitor? And how do you block current flowing from the >input stage of your amplifier into the antenna? The input to the amplifier is just a piece of metal, there is no need for a capacitor in series with it. The output from the amplifier goes to a transformer which drives a piece of "twin-ax" cable back to my lab. The reason for the transformer is that to go really deep in frequency the usual choke to separate the DC supply from RF signal doesn't work. I the 'cable-side' of the transformer, in both ends, is centertapped and that's how I provide power to the antenna. I have successfully received the Russian "Omega-like" system at 9-15 kHz and I have detected but not demodulated the 86Hz submarine transmission. That's DC enough for me :-) -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [email protected] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
