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#1
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As a project to learn more about building radio receivers, I'd like to
build a WWV receiver (or maybe a receiver for the Canadian station CHU, since it's nearby and the format sounds easier to decode). I'm looking for suggestions for how to design such a radio, reading material, etc. I was thinking it might be easier to design a fixed-frequency receiver (rather than a tunable one) because I could just select the L and C in the resonant circuit to give the right frequency. Or, since WWV is at such "round number" frequencies, maybe I could somehow use a crystal oscillator? thank you, Tobin -- http://web.pas.rochester.edu/~tobin/ |
#2
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Tobin Fricke wrote:
As a project to learn more about building radio receivers, I'd like to build a WWV receiver (or maybe a receiver for the Canadian station CHU, since it's nearby and the format sounds easier to decode). I'm looking for suggestions for how to design such a radio, reading material, etc. I was thinking it might be easier to design a fixed-frequency receiver (rather than a tunable one) because I could just select the L and C in the resonant circuit to give the right frequency. Or, since WWV is at such "round number" frequencies, maybe I could somehow use a crystal oscillator? thank you, Tobin -- http://web.pas.rochester.edu/~tobin/ You could build a direct conversion receiver with a crystal oscillator. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com |
#3
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Tobin Fricke wrote:
As a project to learn more about building radio receivers, I'd like to build a WWV receiver (or maybe a receiver for the Canadian station CHU, since it's nearby and the format sounds easier to decode). I'm looking for suggestions for how to design such a radio, reading material, etc. I was thinking it might be easier to design a fixed-frequency receiver (rather than a tunable one) because I could just select the L and C in the resonant circuit to give the right frequency. Or, since WWV is at such "round number" frequencies, maybe I could somehow use a crystal oscillator? You might look at the Ramsey electronics 10 MHz WWV receiver kit. It's a pretty basic crystal controlled superhet/ceramic filter/AM detector with AGC. Tim. |
#4
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![]() Tobin Fricke wrote: As a project to learn more about building radio receivers, I'd like to build a WWV receiver (or maybe a receiver for the Canadian station CHU, since it's nearby and the format sounds easier to decode). I'm looking for suggestions for how to design such a radio, reading material, etc. I was thinking it might be easier to design a fixed-frequency receiver (rather than a tunable one) because I could just select the L and C in the resonant circuit to give the right frequency. Or, since WWV is at such "round number" frequencies, maybe I could somehow use a crystal oscillator? Are you looking to decode the data transmissions or listen to the voice signals. If the former it may take something more sophisticated because you will have to feed a decoder. |
#5
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"John S." wrote in message
ups.com... Are you looking to decode the data transmissions or listen to the voice signals. If the former it may take something more sophisticated because you will have to feed a decoder. Well, the 60 kHz WWVB transmissions were designed to be decoded, and there are a fair number of projects out there to do just that. However, depending on where you are, you can typically only hear WWVB for a small part of the day. ... |
#6
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![]() xpyttl wrote: "John S." wrote in message ups.com... Are you looking to decode the data transmissions or listen to the voice signals. If the former it may take something more sophisticated because you will have to feed a decoder. Well, the 60 kHz WWVB transmissions were designed to be decoded, and there are a fair number of projects out there to do just that. However, depending on where you are, you can typically only hear WWVB for a small part of the day. .. True, but his message did not make that clear. A receiver that tunes to the HF voice signals won't work well on the LF band. |
#7
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"xpyttl" wrote in message
... However, depending on where you are, you can typically only hear WWVB for a small part of the day. Does a bigger antenna help? Or is there just so much more background noise than signal that it's a lost cause? Hmm... isn't the data rate something like 1bps? Maybe they could do some direct sequence spreading at 100Hz or so and improve the link margin a handful of dB... :-) |
#8
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Joel Kolstad wrote:
"xpyttl" wrote in message ... However, depending on where you are, you can typically only hear WWVB for a small part of the day. Does a bigger antenna help? Or is there just so much more background noise than signal that it's a lost cause? Hmm... isn't the data rate something like 1bps? Maybe they could do some direct sequence spreading at 100Hz or so and improve the link margin a handful of dB... :-) And lose the ability to be used as a frequency standard? -- Service to my country? Been there, Done that, and I've got my DD214 to prove it. Member of DAV #85. Michael A. Terrell Central Florida |
#9
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On Tue, 24 Jan 2006 17:20:35 GMT, "Michael A. Terrell"
wrote: Joel Kolstad wrote: "xpyttl" wrote in message ... However, depending on where you are, you can typically only hear WWVB for a small part of the day. Does a bigger antenna help? Or is there just so much more background noise than signal that it's a lost cause? Hmm... isn't the data rate something like 1bps? Maybe they could do some direct sequence spreading at 100Hz or so and improve the link margin a handful of dB... :-) If the problem is more or less random noise, what is the point of spreading the transmit signal, since the same noise density would appear in a specific bandwidth after despreading. And lose the ability to be used as a frequency standard? The GPS signal is DSSS and it can be used as a time and/or frequency standard. Paul |
#10
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In article ,
xpyttl wrote: "John S." wrote in message oups.com... Are you looking to decode the data transmissions or listen to the voice signals. If the former it may take something more sophisticated because you will have to feed a decoder. Well, the 60 kHz WWVB transmissions were designed to be decoded, and there are a fair number of projects out there to do just that. However, depending on where you are, you can typically only hear WWVB for a small part of the day. The same time code is in the WWV HF signals as a 100 Hz, One Baud, pulse duration modulated subcarrier tone. If you've only got a communications grade speaker in your receiver, you may not notice it. Mark Zenier Googleproofaddress(account:mzenier provider:eskimo domain:com) |
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