[Milsurplus] RAK / RAL Receivers: Couple of tips.

[David Stinson]

Been cleaning and reviving a WWII Navy RAK
receiver
which is going to Jim Sargent's next auction in
July.
The beautiful old beast has been patiently waiting
its
turn for about 25 years (I have another I mean to
keep).
De-Ox-it and lubricate,
work over the grounds, then powered and it came
right
up with no issues.  180V B+ plays with about 25mA
current.
Amazing machine; like opening a tomb that's been
sealed  
for millennia, then the occupants sits-up and
says: "Good Morning!"

Those of us who know the RAK/RAL are familiar with

them know this, but for those who have yet to
light one up:
The "headphone" jack on the front of the radio
is NOT for the regular, single-circuit headphone
or for a matched, ground-returned speaker.
The audio output of these receivers is balanced
with a center-tap on the Audio Output transformer
secondary grounded.  If you plug-in a
single-circuit
headphone with one side to the tip and one
side to the ground, you're shorting-out half of
the audio output secondary.
Why RCA snuck this "land mine" in to hoist
the unwary is a mystery.
So use a three-circuit plug if using the
front-panel jack.

An AM signal, like on the BCB, will sound
bassy and "distorted."  Like a certain famous
person is reported to have said:
"This isn't a "bug," it's a "feature."
The RAK/RAL are optimized as CW receivers and
they excel at this, if one does not rail
the Sensitivity control.  If one wishes to 
listen to Rash Windbaugh on the BCB, perhaps
one could bypass the audio filters.

Anyone else want to add some good info
on resurrecting the RAK/RAL?

GL OM ES 73 DE Dave AB5S