[Lowfer] Lowfer Digest, Vol 62, Issue 18

[Alan Melia]

Andy, I suspect that these supplies are switchers, and as such may have some
regulation. See what happens with a purely resistive load drawing the same
current. I reckon the RF from your beacon is getting back into the poorly
decoupled supplies. Also remember that you beacon frequency is probably very
close to the switching frequency, which might be confusing the poor little
thing.

If they are indeed just transformer-bridge-capacitor supplies (few new ones
are these days) Then that is not the cause but anything which active devices
is likely to kick at the RF getting back into it. You can use EMC common
mode chokes as quite big inductors capable of taking a reasonable current.
The are bifilar, so connect the two winding in series to get four times the
inductance....... be careful with the phasing.....end of one winding back to
the beginning of the other.

Alan G3NYK