DIYAPASON-L Digest #329 - Saturday, May 26, 2001 Jon Calvo needs to connect an old solid state relay by "David Doerschuk" <firstname.lastname@example.org> Re: Hooded Trumpet? by <TheGluePot@aol.com> Re: [Residence Organs] Hooded Trumpet? by "Larry Chace" <RLC1@etnainstruments.com>
(back) Subject: Jon Calvo needs to connect an old solid state relay From: "David Doerschuk" <email@example.com> Date: Fri, 25 May 2001 23:49:46 -0500 Hullo folks! Jon Calvo <firstname.lastname@example.org> asked about using an older solid state relay with older Wicks/Austin stop tabs. In a followup post, he added: "the manufacturer of the relay is Solid State Logic, ... my main concern = is will this 1972 relay work with Wicks switching? They are the double = magnet switches, and probably do use a lot of current to activate...can this marriage work?" Jon, a 1972 SSL relay would have been an early version of SSL's Diode Coupling System. These are built to spec at the SSL factory and aren't supposed to be re-configurable in the field. I'm worried that the particular relay you've got may not have an appropriate configuration for your organ. I looked at the SSL web page, and Alan Bragg is their applications engineer. You might want to give him a call at = (703)933-0024, or email email@example.com to see if your relay has the right "layout" for your organ. The answer to your double-magnet question is almost certainly that it will work. I am not familiar with Wicks' magnets (help, someone! :-) but the = SSL system will have no trouble with at least down to 30 ohm magnets (1/2 amp = at 15 Volts DC). The idea of there being two magnets is not as unfortunate = as you might think: first, only one magnet is ever on at a given time = (you're either enabling or disabling the stop, not both simultaneously) and = second, the two magnets are run by separate outputs from the relay so the load of one magnet has almost nothing to do with the load of the other. Really, I'd give Alan Bragg a call. Wicks is, of course, a very well = known and prolific company and I'm sure SSL has had dealings with Wicks' stop action magnets before. All the best of luck! David Doerschuk
(back) Subject: Re: Hooded Trumpet? From: <TheGluePot@aol.com> Date: Sat, 26 May 2001 03:37:49 EDT Hello Dave: Adding hoods might not be cheaper than regular mitering, and here's why. Mitered pipes are best done down in the zinc in the first third of the = total pipe length. If you wanted to mitre the common metal top end you would = have to take into account moving the tuning slot because of the loss of = speaking length. All mitre knuckles cause a loss in speaking length. Down where = the pipe is small in diameter the loss of speaking length is minimized. IF = there were enough extra length after the tuning slot, you could mitre the end of = the resonator to make a hood with no problems. The standing wave in the = pipe extends only up to the tuning slot area after which a non-critical "ghost wave" exists out to the interface between the pipe and "free air." Mitres = done below the tuning slot will require that the slot be somehow moved further up the pipe. Few manufacturers have added enough top metal to do this so you sometimes see hooded pipes where the tuning slot is fully soldered up and extra metal is soldered on to extend the end. This is not = a professionally acceptable standard though I have seen "professionals" do = such. You may also have trouble with one or two of the adjoining pipes that are near to the chamber ceiling. Pipes couple to nearby surfaces which = "shade" the pipe and tend to lower the pitch thus occasionally creating some = speech instabilities. The general rule is to have pipes no closer to a ceiling = than twice the diameter of the pipe but more space is better especially in strings. Shading will also effect regulation. Then there is the problem = of having to remove a pipe for cleaning or repairs so extra clearance is also = needed for that function. Dead length pipes without tuning slots cannot be mitered or altered unless = you really know what you are doing and plan to add speaking length in some = fashion. How much time does it take to do the work? That depends on the quality of = the pipes and how the end mitres need to be done to make the hoods. To do = the job correctly may even mean having to add support struts and bearing points to a pipe with thin walls. Some old supply house pipes and a few cheap builders cost-cutting pipes are so thin and soft that they will sag = no matter how you support them; so, they cannot be done at all. Most = "hooded" ranks originally from a regular builder will have either heavier gauge antimony stiffened common metal or Hoyt metal that won't sag. Figure some = 4 hours per pipe with planning, preparation, cutting, applying whiting, soldering, washing, cleaning, lacquering, regulating (which will have to = be done after any mitres), and tuning. Hope this helps, Al Sefl Who likes Mitres on check bearing Archbishops best........
(back) Subject: Re: [Residence Organs] Hooded Trumpet? From: "Larry Chace" <RLC1@etnainstruments.com> Date: Sat, 26 May 2001 11:11:35 -0400 Dave McClellan's recent query about hooding a Trumpet recalled a sad sight I recently saw, an Aeolian residence organ into which some well-meaning folks had installed the Trumpet from the neighbor's (!!!) Aeolian, replacing the original Oboe (which they then moved to the Echo to place a Vox Humana). The Trumpet's bottom few pipes were already "knuckled", but even so they were too tall for the "new" organ chamber. The installers cut the resonators at a 45-degree angle, turned the top piece, and re-soldered, using resin-cored solder (the remains of which are still visible some 20 years later). Sad to say, the pipes had Hoyt metal tops. This material is lead with a tin foil surface (literally). Mitered over at 90 degrees and without any additional bracing, the pipes all collapsed at the miter joints. The tops fell into the near-by string pipes (also of Hoyt metal), causing damage to them as well. Dave, would it be possible to mount the two too-long pipes at an angle, perhaps behind the others on this offset chest? That might give enough clearance. (I've seen an Austin 16' Open (wood) Diapason mounted that = way.) Another approach would be to cut the tops off and fit an inverted cylinder over them, forming the "Haskell miter". This is pictured in the Barnes book on page 37 of the 7th edition. Such a modification would require cutting, but not soldering, of the reed resonators. The "cylinder" could even be made of wood, as shown on the cover of the "Journal of American Organbuilding" (AIO), for December of 1998. This method causes the pipe = to speak downward, which might or might not be suitable in a given situation. Larry Chace (facing the same problem with my Trumpet!)