[GreenKeys] Loop currents

[Sheldon Daitch]

In regards to the need for a regulated power supply, in most cases, no doubt, no need, as Ralph points out.

In more complex systems, probably more the norm in the non-amateur world, loop current regulators would eliminate the need for readjusting the loop current as equipment is patched in and out of circuits.

>From a long ago world, at one location where I worked, we had Northern Radio Type 238 Loop Current Control units on each local loopof our facility.  Never had to readjust the loop current.

73
Sheldon






      From: Ralph Irish <w8roi at wowway.com>
 To: greenkeys <greenkeys at mailman.qth.net> 
 Sent: Saturday, March 3, 2018 10:28 AM
 Subject: [GreenKeys] Loop currents
   


Another GreenKeys participant was looking for a 'regulated power supply', maybe thinking that
starting with that would be best.  I pointed out to him that the standard loop supply in many Model
28 machines was a simple transformer rectifier and a capacitor to 'smooth out the bumps' created
from rectifying AC.  I've never measured the output voltage of these supplies, but they always 
worked well for me in the "LOCAL" situation when I wanted to use the machine 'off line'. 
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