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#1
Posted to rec.audio.tubes
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Regen
I wanted to play with space charge tubes and had never done a radio
before so here's the result. http://s1243.photobucket.com/albums/...12AL8%20Regen/ I'm not sure what all them 'foreigners' were saying but did hear (English) Radio Taiwan International station identification on 5950 KHz. |
#2
Posted to rec.audio.tubes
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Regen
In article ,
flipper wrote: I wanted to play with space charge tubes and had never done a radio before so here's the result. http://s1243.photobucket.com/albums/...12AL8%20Regen/ I'm not sure what all them 'foreigners' were saying but did hear (English) Radio Taiwan International station identification on 5950 KHz. Hi Flipper, why is this project on photobucket.com instead of the "flipperhome" web site with the usual excellent Flipper textual narrative? -- Regards, John Byrns Surf my web pages at, http://fmamradios.com/ |
#3
Posted to rec.audio.tubes
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Regen
On Fri, 27 Apr 2012 10:16:46 -0500, John Byrns
wrote: In article , flipper wrote: I wanted to play with space charge tubes and had never done a radio before so here's the result. http://s1243.photobucket.com/albums/...12AL8%20Regen/ I'm not sure what all them 'foreigners' were saying but did hear (English) Radio Taiwan International station identification on 5950 KHz. Hi Flipper, why is this project on photobucket.com instead of the "flipperhome" web site with the usual excellent Flipper textual narrative? Well, a combination of things. I began using photobucket as a quick alternate for a few things when my web server box went south (now replaced) and hadn't really intended this tinkering to be 'a project', at least not when it began. And, not being a 'radio guy', I also don't have a frame of reference to know just 'how well' it performs vs other regens. Also, I'm still 'tinkering' and, so, don't think of it as 'finished'. BCB works fairly well but shortwave seems to occasionally do odd things although, when I started, I had no intent of doing shortwave. The original idea was a 'simple' (except it kept getting more complex) and 'safe voltage' project for my nephew but, well, I've built it now. LOL It began with Norm's 12K5 regen. Now that's simple but I wasn't sure nephew would be thrilled with the performance. I then thought a 12AL8 would have more gain. It wasn't much but regen control is a world better. Then the audio preamp was added but I wonder if an RF amp front end would have been a better idea. Anyway, by that time it was complex enough that I wasn't sure nephew would stay interested so I thought to bring it 'almost' complete and let him 'help' finish it. But that turns out to be not quite so simple as it sounds. So then I though maybe have him wind a shortwave coil with the 'wow' factor being *that* is something he can't get on his 'normal' AM/FM radio. Which gets back to the shortwave performance matter, plus what the coil should be because I don't know how to estimate coil self capacitance. The one I have now, 6 + 8 turns with 47pF padder, tunes from roughly 5.9 MHz to 7.45 MHz and appears to have a self capacitance of 24.5 pF but I'm not sure but what the tap ratio is too aggressive and should be more like 3 + 11 turns. |