[Boatanchors] Heathkit IM-2410 Mod (?)

[Alex Eban]

Sensitive equipment is prone to interference through a mechanism called
ground loops: external disturbances enter the unit's enclosure by way of the
power line. If they manage to propagate via the inner enclosure walls and
reach the input, they can wreak havoc to the input signal. It seems probable
that the previous owner, if there was on, had this problem and solved it by
breaking the interference path this way.
Alex	4Z5KS

-----Original Message-----
From: Bob Scott [mailto:w4zy at bobandpenny.us] 
Sent: Saturday, October 25, 2008 7:45 PM
To: boatanchors at mailman.qth.net; FLBOATANCHORS at yahoogroups.com
Subject: [Boatanchors] Heathkit IM-2410 Mod (?)

I have a Heathkit IM-2410 Frequency Counter that looks like it has a  
modification.  There is a rather large toroid with double windings  
that is connected between the front panel input pin to ground. Does  
anyone know what this was for?  I cannot find any reference to it in  
the manual.

Thanks,

73, Bob Scott W4ZY
Woodbridge, VA