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About alex_holden

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    Heavyweight Boxer
  • Birthday 02/06/1980

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  • Interests
    Wood carving, metalwork, Morris Minors, folk music.
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  1. alex_holden

    Reed Chamber Length Experiment

    I see, very clever. I actually rotated my pans the other way, like in this instrument Geoff Crabb built: http://www.concertina.net/rd_new_crabb.html It still gives the improvements in lever length (the worst one is the left hand thumb button). The disadvantage is that, like on a Jeffries, the lowest chambers are a bit cramped for length; the advantage is that roughly speaking the lower notes are on one side of the pan and the higher on the opposite, making it possible to slope the pan to get deeper chambers on the bass side. It doesn't work out perfectly of course due to the Anglo's illogical note ordering and the position of the drone.
  2. alex_holden

    Reed Chamber Length Experiment

    I wonder whether reducing the size of the pad and hole might help with very high reeds, by moving the front edge of the hole further from the tip of the reed. Maybe even change the hole to a oval slot (across the end of the chamber, not along it).
  3. alex_holden

    Reed Chamber Length Experiment

    With the reed shown in the clip, the response was still improving when I reached the maximum extension of my jig, but the improvement per mm of extension was dropping off. If I go up a few semitones, I reach a point part way along the adjustment range after which I don't get any more noticeable change in the response, however I did notice a softening of the tone and reduction in amplitude. I stopped the experiment when I reached a note where I didn't seem to get any improvement from extending the chamber further than the length of the frame. At some point I hope to do some more extensive tests (looking at things like depth, width, radial vs parallel shape, hole size, pad lift), but it seems like it would be easy to go overboard and spend months on the project!
  4. alex_holden

    Reed Chamber Length Experiment

    Hi Frank, are you saying that in your experience, on bass reeds, increasing the depth of the chamber will have a similar effect to increasing its length? It would be easy to make all the chambers in a pan deeper, but that presumably has a negative effect on the higher reeds (more so on an English than on other types, hence why they are usually sloped). I've seen the opposite effect with the highest reeds on a 40 button Lachenal anglo - they worked fine in the open air, but inside the instrument they became very sluggish. Moving walls around to reduce the chamber volume improved matters somewhat, but I couldn't get them to respond as fast as they did on the tuning bench. I suspect the chambers were too deep.
  5. Adrian suggested I post this short video clip over here in the Instrument Construction forum. I've recently been designing a C/G Anglo reed pan, and was wondering about optimum chamber lengths. My understanding is that below a certain pitch, reeds start to respond sluggishly unless they are contained in (or on the bottom side of) a chamber that is longer than the minimum necessary to physically contain the reed frame. If you look at vintage reed pans, you often find that the bass reeds are set in from the outer edge of the pan (I've seen this on both parallel and radial designs). I won't pretend to have reached any conclusive answers or understand theoretically what is going on, but I was able to observe the effect by building a simple variable-length test chamber on my tuning bellows (the idea was suggested to me by Geoffrey Crabb). The reed in the clip is the lowest C from a C/G anglo. I repeated the experiment with the next half a dozen or so pitches. I found that the benefit of extending the chamber increases rapidly as the pitch goes down. Above a certain pitch the benefit was barely detectable. I didn't notice any reduction in responsiveness from making the chamber excessively long, at least in the pitches I tested, though there did seem to be a change in tone. Note that concertina design is an exercise in balancing compromises. It isn't necessarily practical to make every chamber the ideal length. What I learned from this experiment is to prioritise the lowest notes because they benefit the most from extra length. (As it happens, my pan designs ended up looking pretty similar to vintage ones in the end, with a few minor tweaks.)
  6. alex_holden

    Bellows Buckle

    That's a new one on me. 😳 For a couple of years I used something very similar as my car radio aerial, until someone nicked it (the aerial, not the car!). 😄
  7. alex_holden

    Embedding Test

    Just paste in a link to the Instagram post and it happens magically. It does it with YouTube and SoundCloud links too. Very clever!
  8. alex_holden

    Help to identify please

    Anything is possible, but it could take an awful lot of work. If your aim is to enjoy the hobby of restoring an instrument it could be a fun project; if you just want an instrument to play, there are better options out there.
  9. Just trying something out. It looks like the new forum software supports embedding Instagram posts in a topic.
  10. alex_holden

    New look web site

    I'm not 100% certain, but I think if you tick the "Sign in anonymously" box when you log in, it hides you from those lists.
  11. alex_holden

    Bellows Buckle

    Have some of the gussets been patched, maybe on the inside? That can cause unevenness.
  12. alex_holden

    Pop Up Ads

    Thanks Paul.
  13. alex_holden

    Pop Up Ads

    My (limited) understanding of Internet advertising is that ad views alone earn the site little or nothing - it's when people click on the ads that the site gets paid. Occasionally in the past I've clicked on things I didn't actually intend to buy, so the site would earn a few cents (this tends to lead to me subsequently seeing a lot more ads for the same sort of thing), but there's no way I'm clicking on an ad for a dubious-looking dating site!
  14. alex_holden

    Pop Up Ads

    There appears to be a migration script already, though it wouldn't necessarily be a trivial job! https://www.simplemachines.org/community/index.php?board=132.0
  15. alex_holden

    Pop Up Ads

    The old single banner ad at the top of the page is easy enough to ignore, but these new inline ones are much more intrusive. (And no, the ads aren't relevant to my interests!)