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#121
Posted to rec.audio.tubes,rec.radio.shortwave
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Every Journey Begins With a Trip to AAA for maps!
On Sat, 17 Dec 2011 17:44:36 -0600, flipper wrote:
On Sat, 17 Dec 2011 09:48:50 -0800, John Smith wrote: On 12/16/2011 7:34 PM, flipper wrote: ... Yeah, everything was once impossible, that number of "impossible things" shrinks daily ... only one thing is certain in this world, if you say impossible and live long enough, you will be proven wrong ... No one said "impossible" and that's not the question. The question is would enough people want to pay the price for whatever it is. Regards, JS As the old saying, "The longest journey begins with the first step" -- paraphrased. So is the "journey into it can't be done", one step at a time, the first step beginning it, the journey ends with what we have now ... Regards, JS As the old saying goes, "truth hurts" and the question remains, would enough people want to pay the price for whatever it is, no matter how much the arm waving and platitudes. |
#122
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а ы собираетесь продолжать эту тему на www.audiobanter.com , если честно - прикольно!
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#123
Posted to rec.audio.tubes,rec.radio.shortwave
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Every Journey Begins With a Trip to AAA for maps!
On 12/18/2011 4:44 AM, dave wrote:
On Sat, 17 Dec 2011 17:44:36 -0600, flipper wrote: On Sat, 17 Dec 2011 09:48:50 -0800, John wrote: On 12/16/2011 7:34 PM, flipper wrote: ... Yeah, everything was once impossible, that number of "impossible things" shrinks daily ... only one thing is certain in this world, if you say impossible and live long enough, you will be proven wrong ... No one said "impossible" and that's not the question. The question is would enough people want to pay the price for whatever it is. Regards, JS As the old saying, "The longest journey begins with the first step" -- paraphrased. So is the "journey into it can't be done", one step at a time, the first step beginning it, the journey ends with what we have now ... Regards, JS As the old saying goes, "truth hurts" and the question remains, would enough people want to pay the price for whatever it is, no matter how much the arm waving and platitudes. What? You found a AAA map with all the medical marijuana dispensaries depicted on it, routes and location of local bong stores? GREAT!!!! Regards, JS |
#124
Posted to rec.audio.tubes,rec.radio.shortwave
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Building a new shortwave tube radio
On 11/10/2011 9:52 PM, wrote:
With the survivalist market as well as the DIYers who would build a kit I have given thought to the idea of building a new tube shortwave receiver as a usable, practical set. snip Any other comments? Here's a somewhat related discussion: http://www.survivalblog.com/2011/06/...r_prepper.html |
#125
Posted to rec.audio.tubes,rec.radio.shortwave
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Building a new shortwave tube radio
On Nov 28, 3:15*am, wrote:
* Valves have a place in audio, for the truly faithful. But then, audio only requires a few valve types, frequencies are easily managed, and circuitry remains stable for much longer periods of use. *Whereas radio applications require more sophisticated valve construction, and significantly different valve types for given applications, to accomodate frequencies that stretch from 10X to 100000X audio frequencies. * What's comforting in radio with valve technology, is the general sense that the technology itself is accessible. And widely understood to be more forgiving. That valves may be removed, tested, and replaced by the techologically limited, and operated under conditions that would destroy solid state. Whereas, SS receivers, self service requires a much higher level of skill, with a much lower threshold of abuse. For those with limited technological experience, this can be daunting. Especially, as in the case of this receiver, during an emergency, where supply lines are uncertain, and technical support is nonexistent. * I can see where the OP is coming from. Build an accessible receiver that's fairly forgiving to extremes in noise, signal levels, voltage, and hostile events, and you'd have a generally useful rig for the general population in an emergency. It's a nice thought. * But as has been pointed out here multiple times, SS technology in a proper design has proven more resistant to EMP than generally believed, operating voltages are easier to generate, and manage, power requirements are lower, and performace of the technology is dramatically improved since the days of valve receivers. All at a fraction of the cost. And in an emergency, valve supplies will be just as short as SS components. * All of which points to the fact that a well designed kit radio for use in emergencies would be more like the Ten-Tec 1254, than it would be like a Hallicrafters S-40. And the Ten-Tec 1254 is a kit, costs $200, and requires no user alignment, but offers significant performance across the spectrum from LF through HF. * In a package that's available now. *No regen offers simplicity of use and selectivity, nor is the demod audio very good in most cases. *A real SW-3 with a transformer in place of the watchcase headset was tested by a friend in a screen room with HP test gear for SINAD and audio quality. The rig consisted of HP, 8640B and 339A as I recall and minimum AM distortion was six or seven percent, but that was only at something like -20 dBm input and 60% modulation. I can't remember what SINAD was.....it was dismal. *Passive TRF sets, i.e., "crystal radios" were capable of very good fidelity OTOH. The old Millen was capable of equaling the test set's own performance. Again you had to drive the hell out of it though. Regens and distortion... if the regen stage doesnt demodulate, there is no significant distortion. Distortion comes from the prewar approach of using a nonlinear regen stage to demodulate as well. NT |
#126
Posted to rec.audio.tubes,rec.radio.shortwave
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Building a new shortwave tube radio
On Dec 19, 10:26*pm, Mike S wrote:
On 11/10/2011 9:52 PM, wrote: * With the survivalist market as well as the DIYers who would build a kit I have given thought to the idea of building a new tube shortwave receiver as a usable, practical set. snip Any other comments? Here's a somewhat related discussion: http://www.survivalblog.com/2011/06/...r_prepper.html The author here is definitely an eccentric but he has some good ideas. Like the late Mel Tappan, whom I knew as a kid and whom he references frequently, he simply has no idea that 90% of even the small minority perceptive and future-oriented enough to be interested in what he has to say does not have the unlimited funds that would be required to implement some of what he discusses. |
#127
Posted to rec.audio.tubes,rec.radio.shortwave
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Building a new shortwave tube radio
On Dec 24, 10:33*am, NT wrote:
On Nov 28, 3:15*am, wrote: * Valves have a place in audio, for the truly faithful. But then, audio only requires a few valve types, frequencies are easily managed, and circuitry remains stable for much longer periods of use. *Whereas radio applications require more sophisticated valve construction, and significantly different valve types for given applications, to accomodate frequencies that stretch from 10X to 100000X audio frequencies. * What's comforting in radio with valve technology, is the general sense that the technology itself is accessible. And widely understood to be more forgiving. That valves may be removed, tested, and replaced by the techologically limited, and operated under conditions that would destroy solid state. Whereas, SS receivers, self service requires a much higher level of skill, with a much lower threshold of abuse. For those with limited technological experience, this can be daunting. Especially, as in the case of this receiver, during an emergency, where supply lines are uncertain, and technical support is nonexistent. * I can see where the OP is coming from. Build an accessible receiver that's fairly forgiving to extremes in noise, signal levels, voltage, and hostile events, and you'd have a generally useful rig for the general population in an emergency. It's a nice thought. * But as has been pointed out here multiple times, SS technology in a proper design has proven more resistant to EMP than generally believed, operating voltages are easier to generate, and manage, power requirements are lower, and performace of the technology is dramatically improved since the days of valve receivers. All at a fraction of the cost. And in an emergency, valve supplies will be just as short as SS components. * All of which points to the fact that a well designed kit radio for use in emergencies would be more like the Ten-Tec 1254, than it would be like a Hallicrafters S-40. And the Ten-Tec 1254 is a kit, costs $200, and requires no user alignment, but offers significant performance across the spectrum from LF through HF. * In a package that's available now. *No regen offers simplicity of use and selectivity, nor is the demod audio very good in most cases. *A real SW-3 with a transformer in place of the watchcase headset was tested by a friend in a screen room with HP test gear for SINAD and audio quality. The rig consisted of HP, 8640B and 339A as I recall and minimum AM distortion was six or seven percent, but that was only at something like -20 dBm input and 60% modulation. I can't remember what SINAD was.....it was dismal. *Passive TRF sets, i.e., "crystal radios" were capable of very good fidelity OTOH. The old Millen was capable of equaling the test set's own performance. Again you had to drive the hell out of it though. Regens and distortion... if the regen stage doesnt demodulate, there is no significant distortion. Distortion comes from the prewar approach of using a nonlinear regen stage to demodulate as well. NT Hmmmm, never thought about that. |
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