[AMRadio] Link Coupling

Geoff/W5OMR geoffw5omr at yahoo.com
Wed Sep 5 12:19:45 EDT 2007

> In the case of a BC-610 type coil, where the coil is
> stationary, yet rotates on an axis between the two
> stationary coils, maximum coupling will occur when
> the turns on the link are paralleled with the turns
> the coil.
> There's no confusion about coupling.  The magnetic
> lines of flux prove that, daily.

It's the same, Rick, as mounting your grid-input coil
turned 90 degrees from your plate coil, to reduce the
effect of the grid-input from interacting with the
plate output.  This also helps easy neutralization.  

MY big 250TH final was built back in the mid-50's (not
by me) by a non-ham, who was building the rig, had an
interest in electronics and had friends who were
already hams.  He built the transmitter out of some
HRRL handbook(s).  

*I* would have thought that having the grid input
coil, and it's swinging link -below- the steel chassis
would have been enough physical space to counter-act
the interaction effect between input and output

Not the case.

this became even more evident when I went to visit
Dave/W4QCU in Oak Ride.  His "Big Bertha" rig, has a
pair of 100TH's in push-pull, link coupled, and the
grid input coil and the plate output coil are both on
the same side of the chassis.  the big difference is,
in Dave's rig, the two coils are at right-angles to
each other.  Ergo, no interaction, and neutralization
is smooth and simple.


73 = Best Regards,

Need a vacation? Get great deals
to amazing places on Yahoo! Travel.

More information about the AMRadio mailing list

This page last updated 15 Dec 2017.