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![]() This is hopefully going to end up as a class project and therefore the goal of learning how to build your own antenna and receiver is the reason I'm not intending to just go and use someone's "all in one" WWVB receiver IC (even though colleges seem to push that approach these days... but then _someone_ had to design that IC, right!?). Hans Summers has a nice section on his website in the UK that has full particulars of his 1991 first-year university project of a 60 KHz receiver-decoder for the Rugby station there. He used discrete TTL packages for the entire decoder! [Rugby modulation code a bit different compared to WWVB] http://www.hanssummers.com/electroni...o/radioclk.htm Hans (who appears in here from time to time) has _everything_ on that project available there. Interesting! If I type the link incorrect, just get www.hanssummers.com and navigate from there. Interesting website with lots of different projects well-described. Thanks Len. I always read in here but rarely find the time to post anything much. My 60KHz receiver was just a Tuned Radio Frequency (TRF) design and very poor, indicating the state of my knowledge of receiver architectures at the time. If I were doing something similar today I'd do it very differently. I'd probably use a crystal oscillator divided down to something near 60KHz and heterodyne that down to audio frequencies for further filtering to get the 1 pulse per second, with coded length. I'd probably still make the decoder in TTL though ;-) The MSF Rugby transmissions are a 60KHz carrier interrupted each second for either 100mS representing binary 0, or 200mS representing binary 1. Details at http://www.npl.co.uk/time/msf.html. Rugby is a town as near to what one might consider to be the centre of England as could be judged. By coincidence I happened to drive past the antenna farm on Saturday on my way up the motorway. I'd previously seen the antennas from a great distance but up close: very impressive. There are 12 huge masts. I think there are 12, but you don't want to spend too much time looking at the antennas and not the road, or you'll join the wrecks of all the other unfortunate radio amateurs strewn along the motorway embankment. Who no doubt departed this mortal coil happily dreaming of how many wavelengths above ground they could put their HF antennas ;-) As you get closer, a whole forest of smaller masts becomes visible. There's a picture here http://www.subbrit.org.uk/sb-sites/s...io/index.shtml. Actually, reading that now shows there are indeed 12 masts, 820ft high each one, so my count was correct. I read somewhere else that there is a plan to close the Rugby site, a pity. 73 Hans http://www.HansSummers.com |
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