RADIOTEL@....... wrote: > Meridith Lamb > I appreciate the extensive infomation you provided regarding the hall sensor. > I have built a STM-8 basic seismo which is presently configured as a coil > magnet unit (4 sec. period) since I am not presently skilled enough to tackle > the electronics that Sean-Thomas's unit require. I previously exchanged > e-mail with Sean-Thomas regarding using the traditional SG electronics with > the STM-8 of which he was encouraging for me to try. However, it sounds like > the hall effect approach would be almost a natural for this use and > especially for someone with very limited electronics skills. > Jim Allen > Cerritos, Calif. > Jim, If I read you correctly in regard to using the Hall on the STM-8 frame, that will be most interesting to see how well it does, besides helping elevate the electronics experience somewhat. I also lack a lack a heck of a lot of experience....its just the way it is. I've never tried it on a vertical yet, but I think you will see a more interesting increased "period". One could also use a dual approach here, to make it even more interesting. Simply leave the coil/magnet as is, because it will sense the nearby quakes P & S waves well. After building the circuit, add a very light extension on the same seismo end for the Hall circuit; and that way you can get kind of both worlds, the near by quakes and some more teleseisms you wouldn't normally see very well with the coil/magnet. Suggest building the circuit and getting used to it via a tempory route of wires and hand manipulating of the magnet near and far and from side to side. It takes awhile to get used to it, as its different than a straight amplifier where one only adjusts the gain, filter or etc. Of course on your seismo the Hall would be mounted on the boom, with the 4 pole magnet on the base frame. To be honest.....(ha), I've shorted out more than just afew diodes and capacitors with the wrong polaritys. Take care, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>