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   rec.audio.tubes      Tube-based amplifiers... that go to 11      52,877 messages   

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   Message 51,667 of 52,877   
   Michael Black to All   
   Re: Building a new shortwave tube radio   
   03 Dec 11 12:09:35   
   
   a641617f   
   XPost: rec.radio.shortwave   
   From: et472@ncf.ca   
      
   On Fri, 2 Dec 2011, NT wrote:   
      
      
      
   > Does anyone other than John think there's commercial mileage in   
   > modular radio now?   
   >   
   Not as portrayed, and certainly not as a general radio.   
      
   There have been articles about building in modular form and even some kits   
   that were modular, and of course it's a great form for experimenting, why   
   remake the whole radio if you want to try a new IF strip or add a new   
   detector?  Or buy the modules you want to build up something, rather than   
   be stuck with what the complete radio the company sells.   
      
   But there can't be a general bus, one module takes its input from the   
   antenna or a previous module, and its output goes to the next module,   
   those have to be well isolated.  The power supply is standard to each   
   module, the whole point of three terminal regulators was to make   
   regulation specific to boards rather than one big power supply feeding   
   everything.  But control lines will be different depending on the function   
   of the module, some requiring lots of lines, others requiring few or none   
   at all.   
      
   And there's no way it would be for everyone.  The average radio user   
   doesn't care, they just want AM/FM radio, nowadays not even AM and a radio   
   is a radio, once you have one for average use there's no need for   
   improvement.   
      
   A modular radio might be interesting to the hobbyist, which of course is   
   where the concept has travelled.  It's there in all the VHF converters   
   described in the hobby magazines, getting extra coverage with a shortwave   
   radio at the cost of a "module", ie converter, rather than having to build   
   a whole new radio.  It's the hobbyist that wants to try things, it's the   
   hobbyist that is interested in the radio in itself.  They are the ones who   
   might want to do better on longwave, or listen to the police band (even   
   then, or a lot of that type of hobbyist, existing scanners are more than   
   enough).   
      
   For a small company aimed at the hobbyist, modules make sense.  They dont'   
   ahve to offer multiple receivers, just enough modules for someone to put   
   together what they want. I long ago argued with a friend that if he was   
   going to go into a small electronic business, just selling boards made   
   sense, since then he's not involved in dealing with cabinetry.  The   
   hobbyist can buy the modules and then take care of putting it in a case.   
      
   It's a fairly limited market, yet at one point was one that might do okay.   
   You can have a successful business without making loads of profit, and   
   indeed doing away with things like UL approval by using an existing AC   
   adapter or having the buyer come up with one keeps overhead down, as does   
   the lack of cabinetry.  Find a market that really exists, and cater to it,   
   you may not be rich but the business may keep going.   
      
   I have no idea if the market is there anymore.  I've been going through   
   old magazines lately, and it reminds me how much time and even money I   
   spent on magazines, the hobby electronic ones and the ham magazines, and I   
   feel detached to it as the magazines disappeared, virtually no hobby   
   electronic magazines in North America, and the ham magazines dwindling but   
   more important less available on newsstands than in the old days.  The   
   magazines were pretty important, and I'm not sure they really have been   
   replaced with other things.  If nothing else, they were  way to keep track   
   of the companies that sold kits and parts.   
      
   A different way to look at it is to think about commercial shortwave   
   receivers.  They have become really cheap, and fairly good.  I paid   
   somewhere around $80 for a Hallicrafters S-120A (the transistorized one)   
   in the summer of 1971, the most I could afford, the cheapest receiver   
   I could find locally.  It was junk, the only good thing about it was I had   
   no experience so I didn't know how bad it was for a bit.  You can get a   
   Grundig Yacht Boy 400 (or whatever the same model in a different cabinet   
   is) for a hundred dollars, some of the other Etons for the same complete   
   with synchronous detector.  For that matter, I am finding sw receivers   
   at rummage and garage sales now for pretty low amounts.  That Grundig   
   Satellite 700 for 2.00 at the Rotary Club sale, that Sony ICF-SW1 at a   
   garage sale in September for 10.00 (and then about half an hour later an   
   Eton Mini 300 for 2.00 at another garage sale, though that is junk).   
      
   They are infinitely better than the old low end analog receivers.   
   People talk about buying all kinds of models, but nobody seems to think   
   that if a hundred dollars is seen as "disposable" then why not buy a radio   
   to modify extensively?   
      
   Buy one and put it into a bigger cabinet.  Make it a desktop physically,   
   complete with a good tuning knob on the front panel.  Even receivers with   
   up/down buttons can be tuned with a tuning knob.  All those people who   
   judge a radio by "sound", they can put a nice big speaker in the cabinet,   
   though better to use an external speaker.  Add better lighting to the LCD   
   display.  Add that Q-multiplier.  Add some filters if you can get some at   
   the proper IF frequency.  The radio becomes the foundation to customize.   
   Add an FM IF strip and then feed the radio with converters to hear those   
   higher bands.  Put some more front end selectivity in the box, yes   
   suddenly you'd have to tune it in addition to the tuning knob, but that's   
   the way it used to be on the good receivers anyway.  It doesn't have   
   fine enough tuning?  Then add a variable capacitor across the second   
   conversion oscillator (either directory or via a varicap), and you can get   
   a fine tuning knob that isn't linked to the BFO.  For that matter, one   
   could splurge and add crystal controlled BFO, getting the frequencies to   
   be in the right place in relation to the IF filter.   
      
   What's wrong with current receivers that can be improved with a little bit   
   of work?  Some things can't be fixed, but a lot of these new receivers   
   offer a pretty good foundation compared to what there was in the old days.   
      
   YOu start with a reasonably good receiver, you see the low cost so you   
   aren't afraid to hurt it, and you make it the receiver you want, just like   
   someone would want those modules for.   
      
      Michael   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)   

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