The original poster is talking about signals in the tens of HERTZ not tens of KiloHertz. There are many pages where people discuss work to receive VLF/ELF signals of natural origin and I think some of these sites also talk about attempts to receive the man-made ELF signals. However, I think that the US has stopped using the VLF/ELF submarine transmitters - presumably because they have some better technology that is not public yet. I don't know about the russians. Some examples: http://www.vlf.it/kurt/elf.html (mentions reception of man-made signals) http://www.ab9il.net/vlf/vlf1.html (mentions reception of man-made signal= s) http://www.vlf.it/zevs/zevs.htm (about a Russian system) http://www.backyardastronomy.net/vlf_receiver.html http://www.northcountryradio.com/Kitpages/elfrcvr.htm http://www-star.stanford.edu/~vlf/ulp_reciv/ulp.htm http://home.pon.net/785/equipment/build_your_own.htm http://spaceweather.com/glossary/inspire.html http://www.auroralchorus.com/bbb4rx3.htm http://www.techlib.com/electronics/VLFwhistle.htm http://www.qsl.net/dl4yhf/speclab/vlf_rcvr.htm http://www.auroralchorus.com/wr3.htm Sean On Tue, Jan 3, 2012 at 2:31 AM, Bob Axtell wrote: > I suggest that you buy a WWVB module and adjuat the frequency slightly > with a new crystal. WWVB is a time/date signal from Ft Collins, CO USA > sending at 60.00khz. The modules are available from Digikey for about > $10 USD. > > --Bob A > > On Mon, Jan 2, 2012 at 11:12 PM, fred jones wrote: >> >> Hi all, >> =A0I have a question for those analog engineers on the list. =A0I have b= een searching the internet for information on listening to ELF signals. =A0= I have found some information but not exaxtly what I'm looking for. =A0For = example one site has a circuit of amplifiers and passive filters utilizing = either an antenna or just probes stuck in the ground to receive ELF signals= below 50Hz. =A0Another person has a very large coil of wire wound on a spo= ol and just sets it on the ground. =A0What I would like to do is similar bu= t I'd like to listen to 76Hz which is the US submarine communications frequ= ency. =A0The Russians utilize 82Hz. =A0Is it possible to build a circuit th= at would pickup the 76Hz signal only? =A0Any information on how to do this = if it is possible is appreciated. >> Thanks, >> FJ >> >> http://www.vlf.it/kurt/elf.html >> -- >> http://www.piclist.com PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .