02-16-2021, 01:15 AM
(edited by admin)
This was a email rejected by workbench for the time being so please see if you can help me I have read all the places on internet including how things work very good article on shadow meters but they all talk about circular or horseshoe magnets under vane but mine doesn't have that please read on:
Hi I have a Philco 630F with a shadow meter different from the one described in the very helpful article it is the old-style box type and it was working until I messed with it figuring I could make the internal permanent magnet stronger by place a super magnet close to it .Well, dumb and dumber idea it stopped working, and became un-centered. So I took it apart. The coil test good at a little over 1k. I very carefully cleaned and set the tension so the needle is very free moving this is correct right? I took the coil apart from what I surmise to be the permanent magnet post which has no magnetism. I have tried several times to magnetize this using a very strong Niobium magnet with no luck. I have tried wrapping wire around it hooking it up to first dead short across 12v car battery briefly several times, no luck hooked up a test light in series with this setup (16 gauge wire) ran that for several minutes ,nothing. I then tried running a headlamp in series with it hooked up a battery charger ran that for at least three minutes. I can't figure out why it won't magnetize is it the copper plating? As I inspect this at the pivot point of the vane there is a copper plated little bar is this the heart of the unit? Does this need to be in the center of the two little tabs that are at the end of one end of the copper plated iron u shape core and the metal screw holding the coil and vane bracket in a magnet flux to keep it centered without power. I understand that when radio is off station you get more voltage from AVC kicking in, this deflects the vane from center position and gives more shadow Is this correct? So, my question is, does this type use the permanent magnet. I know this is lengthy should've just left it alone . Regards. Paul
This was a email rejected by workbench for the time being so please see if you can help me I have read all the places on internet including how things work very good article on shadow meters but they all talk about circular or horseshoe magnets under vane but mine doesn't have that please read on:
Hi I have a Philco 630F with a shadow meter different from the one described in the very helpful article it is the old-style box type and it was working until I messed with it figuring I could make the internal permanent magnet stronger by place a super magnet close to it .Well, dumb and dumber idea it stopped working, and became un-centered. So I took it apart. The coil test good at a little over 1k. I very carefully cleaned and set the tension so the needle is very free moving this is correct right? I took the coil apart from what I surmise to be the permanent magnet post which has no magnetism. I have tried several times to magnetize this using a very strong Niobium magnet with no luck. I have tried wrapping wire around it hooking it up to first dead short across 12v car battery briefly several times, no luck hooked up a test light in series with this setup (16 gauge wire) ran that for several minutes ,nothing. I then tried running a headlamp in series with it hooked up a battery charger ran that for at least three minutes. I can't figure out why it won't magnetize is it the copper plating? As I inspect this at the pivot point of the vane there is a copper plated little bar is this the heart of the unit? Does this need to be in the center of the two little tabs that are at the end of one end of the copper plated iron u shape core and the metal screw holding the coil and vane bracket in a magnet flux to keep it centered without power. I understand that when radio is off station you get more voltage from AVC kicking in, this deflects the vane from center position and gives more shadow Is this correct? So, my question is, does this type use the permanent magnet. I know this is lengthy should've just left it alone . Regards. Paul
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