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On Sat, 13 Nov 2004 07:20:09 GMT, m II
wrote: Is the Superheterodyne set over rated? It seems to me there were certain advantages to the OLD ways. Ease of control perhaps not being one of them. Actually, superheterodyne is a pretty "OLD" way. It's just that it has not been surpassed - till now, with the SDR - Software-Defined Radio (of which superheterodyne is the front end anyway). What was the WORST feature of the Regenerative sets? Selectivity, dynamic range, tricky adjustment. The BEST feature? Simplicity, cost. Would it be worthwhile to build a kit? It is *always* worthwhile to tinker with radios... ;-) Mike |
"m II" wrote in message news:JAild.83554$E93.76920@clgrps12... Is the Superheterodyne set over rated? It seems to me there were certain advantages to the OLD ways. Ease of control perhaps not being one of them. What was the WORST feature of the Regenerative sets? The BEST feature? Would it be worthwhile to build a kit? mike I built a single compactron tube ( 3 tubes in 1 envelope) regen several years back: http://parelectronics.com/pics/regen2.jpg Lots of fun to listen to casually, but one quickly tires of the poor selectivity and fiddling. Dale W4OP |
m II ) writes: Is the Superheterodyne set over rated? It seems to me there were certain advantages to the OLD ways. Ease of control perhaps not being one of them. What was the WORST feature of the Regenerative sets? The BEST feature? Would it be worthwhile to build a kit? You have to remember that Howard Armstrong, who "invented" the regen (he was issued the patent, but it's something you really just trip over rather than invent). then went on to invent the superheterodyne, which does seem to have come from deliberate effort. He was disatisfied with the regen, which led him to experiment and explore until he came up with the superhet. The regen is simple, and that's a big advantage. It provided good gain for a single stage, and it provides better selectivity than a single tuned circuit without regeneration. Beyond that, it's limited. It won't provide great selectivity, it is finicky, and can receiver limited types of modulation. No, it can't be a serious contender for the superhet. On the other hand, there is certainly an appeal to building something, and a regen does make it easier. One can even argue that if someone is going to build a simple receiver, a regen makes more sense; not only simpler, but suffering from none of the superhet's disadvantages when done simply. Some of the disadvantages, apart from the lack of good selectivbity, can be overcome at the cost of more complexity. Add an an amplifier stage before the detector, to isolate it from the effects of the antenna (which can cause the regen to go in and out of regen when you don't want it), add some voltage regulation, add an audio filter. Make sure theregen control is smooth. Charles Kitchin has done a fair amount of work on regens in recent years. Some of the circuits are floating around the web, and he's had quite a few articles in QST. I'm too lazy to dig up the biography once again. There have been a few other "improve the regen" articles in QST in the past decade, though I can't remember dates or author. The first used an optoisolator to add some isolation, and there was another using a bridge for isolation. Michael |
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Michael Black wrote: David ) writes: Edwin, not Howard. No, that's not an error, it's Edwin Howard Armstrong, and I've come across instances to suggest that he prefered to be called Howard. That certainly makes sense as author Tom Lewis in the book "Empire of the Air, The Men Who made Radio" generally refers to him as 'Howard Armstrong'. dxAce Michigan USA |
you can also have the benefits of both by building a super-regenerative superhetrodyne receiver ;-) the old Boy Scout Radio Merit Badge from the 1960s had such a design, which I built at the time, and the resulting radio receiver outperformed many commercial models costing much more ;-) grins bobm -- ************************************************** ********************* * Robert Monaghan POB 752182 Southern Methodist Univ. Dallas Tx 75275 * ********************Standard Disclaimers Apply************************* |
m II wrote in message news:JAild.83554$E93.76920@clgrps12...
Is the Superheterodyne set over rated? It seems to me there were certain advantages to the OLD ways. Ease of control perhaps not being one of them. What was the WORST feature of the Regenerative sets? The BEST feature? Would it be worthwhile to build a kit? mike TenTec and MFJ both offer regen radio kits. I built the TenTec 4-bander a few years ago. A very simple kit and well worth the time to build. A fun radio to play with about once every 2 years or so, mainly because the gee-whiz factor doesn't last very long. Still is was worth the time assembling it. |
On Sat, 13 Nov 2004 07:20:09 GMT, m II
wrote: Is the Superheterodyne set over rated? Useful Bandwidth control and true synchronous detection are things you cannot do with a Regen. Try receiving SSB or FM with a Regenerative receiver. It seems to me there were certain advantages to the OLD ways. Ease of control perhaps not being one of them. What was the WORST feature of the Regenerative sets? Selectivity and stability . Calculate the Q required for a 5Khz channel at 20 Mhz... The BEST feature? Simpllicity. You could build a fairly useable radio with just 3 stages, in fact quite a few 27 Mhz walkie talkies were built that way, with the Regen detector doubling as the Oscillator/output stage in transmit. Would it be worthwhile to build a kit? mike |
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