[GreenKeys] Testing My Model 15 KSR

[John McClung]

Thanks for the info.
 
Looks like I have the holding magnets with the toggle switch.
 
Which is the better way to run it, 20mA or 60mA?
 
John

	-----Original Message-----
	From: WA5CAB at cs.com [mailto:WA5CAB at cs.com] 
	Sent: Monday, April 12, 2010 10:58 PM
	To: John McClung; greenkeys at mailman.qth.net
	Subject: Re: [GreenKeys] Testing My Model 15 KSR
	
	
	John,
	
	To add to or comment on what's already been posted, relatively
few Model 14/15/19 will run on 20 mA.  That requires different magnets
in what's called a "Holding Magnet" selector.  The majority come with a
"Pulling Magnet" selector.  You can tell the difference by the fact that
the pulling magnets are cylindrical and the holding magnets are
rectangular in cross section.  I've had in my lifetime maybe 30 14's or
15's and only about two had holding magnets.  However, the first M15 I
ever had (in 1962) had holding magnets.  So they do turn up.  But both
of the ones I recall having had a selector toggle switch, too.  I can't
certify that all did.
	
	You can't rewire a pulling magnet selector for 20 mA.
	
	If you do not disconnect the wires actually going to either
coil, you will not accidentally get them wired so that they buck
(oppose) each other.
	
	Hooking the local keyboard and selector magnets in series with
the local loop supply (with dropping resistor adjusted to set the
resting current to 60 mA) creates what's commonly called a local loop.
Typically used for testing and generating local hard copy.  You can jack
a TD or keying generator into the loop and run a FOX tape and check and
adjust range.