[GreenKeys] Update on my open M15 Selector Magnet

[Doug Alderdice]

I had a very similar problem with my M.26 machine.  Not long after I got 
it I discovered that it was running with only one magnet, and the other 
had a divot in it.  I was able to do a little microsurgery on the magnet 
in question and found two ends of coil wire that, when jumpered, gave me 
continuity on the coil.  So I soldered in a jumper and wrapped the coil 
back up in friction tape and it has been going well since.  I have pix 
somewhere, I can dig them out if there is interest.  I think I posted 
them on this list at the time.

73,

Doug, KA2WFT


On 10/6/2020 5:46 PM, ad7i wrote:
> Well, this is a little embarrassing.  As you may recall, I found that 
> one of the two selector magnets on my Model 15 TTY had gone open, and I 
> had speculated on some of the possible causes.
> 
> It now appears more likely that the magnet is open due to a divet in the 
> side of the magnet.  I've had this TTY for about 25 years and I don't 
> know if I received the TTY this way, or if this was something I managed 
> to do while it was in my care.
> 
> The good news is that the machine does seem to print fine with just one 
> magnet working, and the power dissipated by the one magnet at 60 mA of 
> current is slightly less than 350 mW, which isn't all that much.  
> Additionally, a temperature check with my index finger doesn't indicate 
> any heat from the working magnet.
> 
> Below is a photo of the divet; I can't imagine how I missed that.
> 
> m15-magnet-divet.jpg
>