0b1a9952   
   XPost: rec.radio.shortwave   
   From: dpetermaus@att.net   
      
   On 11/27/11 21:15 , rrusston@hotmail.com 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.   
      
      
      Audio quality in an emergency doesn't have to be good. Only   
   intelligible. And a regen can be quite simple to operate. Any tricks   
   to learn will be learned as a matter of necessity. But for an   
   inexpensive, and accessible kit form radio, a regen is not a   
   particularly poor choice.   
      
      For instance, from Ten-Tec:   
      
      
   Model 1054 4 band regenerative shortwave receiver kit. Here it is:   
   PROOF that the classic “first receiver” project need not be more   
   expensive today than our favorite 1950’s kits. In fact, this great   
   little receiver beats the pants off those 3-tube radios with the big   
   plug-in coils. Excellent for clubs, classes and family activities.   
   Band coverage: 49 meter SWL band, 40 meter ham band, 31 meter SWL   
   band, plus 12-15 MHz tuning for daytime shortwave listening, 20   
   meter ham band and all those other shortwave sounds. You can enjoy   
   the basic kit just by hooking up 9 to 12 volts DC, setting up a   
   modest wire antenna (10 feet or more of hookup wire) and plugging in   
   your own stereo headphones (1/8” plug). Features convenient push-   
   button bandswitching, on-off switch, “on” LED, tuning, volume, and   
   regeneration control. Case, knobs, and speaker not included. We   
   recommend case (undrilled, no holes) TPx-43 for this receiver,   
   available in unpainted aluminum, black or charcoal. Order TP-43 for   
   aluminum, TPB-43 black, TPC-43 charcoal. Building skill level:   
   Beginner. No previous kit building experience needed. Must be able   
   to solder, read instructions, and use small hand tools. $39   
      
      
      So, again, getting back to the OP's original premise: A kit form   
   radio, useful in emergencies, that is simple to build...such animals   
   are already available. Building one with tube tech, is simply a   
   matter of bringing it to the party too late. More reliable, less   
   expensive, more accessible, lower power, higher performance   
   technology, has existed for decades. And is currently available in   
   kit form at low cost.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)