Adams-Morgan Paragon Type Two
Alexander D. Schapira, 2011-2014, All rights reserved
I acquired this Adams-Morgan Paragon Type Two receiver
because in the 1920's the Adams-Morgan company was located in Montclair,
New Jersey, where I live.
I thought it would be neat to have a hometown radio, even though this one was
not in very good condition.
thanks to all who provided suggestions,
I am providing this account of
how I repaired anAdams-Morgan Paragon Type Two
I hope this will be of
some interest to other Adams-Morgan afficionados.
The set was extremely dirty, so my first task was a cleanup.
The amplifier tube socket was cracked, and virtually every screw terminal was loose
and every soldered joint crumbled apart when touched.
There is remarkedly little information on this set available anywhere.
Steve Rosenfeld amazingly dug up some hand drawn schematics, sans component values.
Here are the values of the components in my set:
Al Klase kindly provided me with a copy of an article about the Adams-Morgan Company.
- Grid leak glass resistor labeled 4. M (open)
- Grid leak mica capacitor labeled .00025 (Dubilier)
- Filament rheostat max 7 ohms (measured)
- Tuning capacitor 20-460 pF (measured)
My Type Two came with a Wizard X-201-A in the detector socket and a
Cunningham CX-300-A in the amp socket.
This does not make sense, as the 201-A
is a better amplifier than detector, and the 300-A is described as a detector.
(The 300-A turned out to be bad.)
Also, the interstage audio transformer was clearly not an original Adams-Morgan unit.
When I finally got to work on it, as I expected, the
secondary of the interstage transformer appeared open,
as was the glass tube grid-leak resistor.
I rebuilt the 4 meg grid-leak resistor by replacing the carbon-paper
element inside the glass tube with a modern discrete resistor.
There are a number of differences
between my set and various pictures of the Type Two
The two biggest differences are
The grid-leak resistor
- My set has six binding posts out the back of the cabinet connected
inside to various points, whereas in the on-line pictures there are no
binding posts, but rather an internal row of six terminals on a bakelite
- My set has the detector tube near the back rear corner of the set
and the grid leak is between it and the tuning capacitor, whereas in the
pictures, the grid-leak is in the corner and the detector tube is to its
The coil, tuning capacitor, rheostat, grid leak assembly, and front panel all look like the
ones in the on-line pictures. Amazingly, the grid-leak capacitor,
an early Dubilier unit, was still within spec!
The grid-leak capacitor
There was probably a lot variation in the manufacture of
these sets near the end of their production, but it is also possible that
the set was modified when the original interstage audio transformer was
replaced. To check this, I removed the detector tube socket and
underneath found screw holes that match the grid-leak assembly. So its
entirely possible that the detector tube and grid-leak were moved
(interchanged) to make room for the replacement transformer. I did not
remove the transformer to see if there are holes underneath it for
a tube socket.
There is no sign of a bakelite bracket for an internal terminal strip.
I decided to rebuild the set configured as I found it.
I found that almost every soldered connection virtually fell apart when
barely touched. Also, every screwed terminal was loose and corroded.
It took a while to repair all the bad wiring and connections.
I repaired the cracked tube socket,
cleaned the hardware,
and repainted the engravings on the knobs and front panel.
I also replaced the cracked center knob of the main tuning dial with one on hand,
although it is slightly larger than the original.
Here is the chassis cleaned and repaired.
Cleaned up hardware
After I rebuilt the grid-leak resistor, repaired all of the bad
and corroded connections, fixed loose terminals on the tube sockets,
and replaced a bad tube, I got it to work with three outboard power
supplies. I used about 35V B+ on the detector, 70V B+ on the amplifier, and 5V
for the filaments. I hooked up an outboard audio output transformer
and speaker. The Type Two receives the standard
AM band even with a short antenna and drives an 8" speaker
through a small audio output transformer to a reasonable volume.
The inter-stage transformer secondary originally appeared open because the inner
set of nuts on its terminals were loose and corroded, apparently not
making contact with the winding. Once these were cleaned and tightened,
the secondary showed 7.5 K. So, I don't need to replace the
transformer for functionality, but I may do so for originality's sake.
The circuit is a regenerative detector in which one varies the positive
feedback to act as the volume control. You adjust it for maximum volume
just short of oscillation. Its the first time I worked on a set of this type.
The bad 300-A tube was weird. It has an intermittent internal short that
continually makes/breaks/makes/breaks... as long as the filament is energized.
My next task was to complete the restoration of the cabinet.
First, I removed ninety years of dirt and grime. I did not attempt to repair the nicks
and other defects in the cabinet.
Then I brushed on a couple of coats of lacquer,
lightly sanding with 600 grit paper in between coats.
This was followed by a vigorous rubdown with nothing but a paper towel.
Then the chassis was reinstalled and the binding posts connected up.
There was an extra hole in the front panel.
A small black snap-in hole cover doesn't look too bad filling the hole.
I had a lot of fun bringing this set back to life and restoring a piece of Montclair history.
I hope you enjoyed the story.
-Al Schapira, W2ADS
Please feel free to contact me at
Page last modified 04/17/2014