My Freed-Eisemann FE-15

With thanks to all who helped and provided information and
encouragement, I am happy to say that I have gotten my
Freed-Eisemann FE-15 working. For those interested,
here is what I have done so far, and what remains to do:

While on vacation last summer I visited an antique store in Eastern Massachusetts
where I found the chassis of a Freed-Eisemann FE-15.
It was wrapped in old newspapers from 1964, but never-the-less was covered in grunge.
All five UV-201A's were there, but it had no cabinet and was missing two of the three large knobs
and both of the smaller rheostat knobs. I decided to take a chance on it.

After the initial cleanup, it looked like this.
BEFORE/FE15top.jpg

The starting point

I downloaded a schematic from Nostalgia Air (Thanks!).
Two of the UV-201A's had open or intermittent filaments, or so it seemed.
Two of the transformers had open windings,
and the two wire-wound resistors, and the grid leak resistor were open.

I have never worked on a TRF set before but I was
encouraged by list members to attempt a repair.
Here is what I did.

Repaired two UV-201-A's that had internal intermittent contacts.

I unsoldered the pins and gently removed the old cement,
separated the base from the glass, cleaned and tinned the leads,
re-glued the base (using Elmer's White, per previous discussion)
and re-soldered the pins. Both now have solid connections and
work fine in the FE-15 and in a test jig.

Repaired the glass tube grid leak resistor by replacing the carbon strips with a 2 Meg resistor.

Repaired two wire-wound 500 Ohm resistors by finding and reconnecting the open windings.

Temporarily bypassed both interstage AF transformers (that had open windings).

One of them (on the left, below) was itself a replacement transformer that had gone bad.
I now know that open transformers are very common in sets of this type
because of the fine wire used in the transformer windings.

I used RC coupling to get around the open transformers.

For the coupling from the detector to the 1st audio stage,
I used 100k in the detector plate through .1 uF to 1 Meg at the 1st AF grid to C-.
(Only the secondary of the 1st transformer was open,
but I removed the primary lead when I inserted the 100k detector plate load.)

For the 2nd audio stage and I used 100k in the plate of the 1st AF stage,
coupled with .01 uF to 1 Meg to C- in the grid of the 2nd AF stage.
(Only the primary of the 2nd transformer was open,
but I removed the secondary connection too).

These values were determined empirically using
RC substitution boxes adjusted for best results.

I used outboard power supplies for 90V, 22 1/2V, -4 1/2V and 6V filament supplies to test with.

Here is what the lash-up looked like on the bench.

Substitution for the speaker

Not having any suitable high impedance speaker to plug into the
output jack, I used a 10k resistor (the output jack is in the
plate circuit to 90 volts) and coupled a little transistor
amplifier to it. (The value of 10k was again determined
experimentally.) Voila! AM stations heard!

Repaired and refinished an original FE-15 cabinet.

I was lucky enough to get an original FE-15 cabinet
and two original large F-E type 360 knobs thanks to Travis Ogden, a reader of my initial post.
The cabinet needed major work.
(Notice someone had attached the top to the lid.)

Before

After

Cleaned and buffed the knobs and front panel and repainted the dial and panel engravings.

I used gold acrylic paint and wiped off the excess around the engravings.

I built the two RC stages with discrete components onto terminal strips and hid them under the chassis.

(This is reversible if I locate the appropriate transformers.)

I built a custom power supply in a Bakelite enclosure to match the bakelite front panel of the FE-15.

I measured the current draw on the bench and found that I needed

      A supply:        6V @ 1.0 - 1.25 A
   B1 supply:       90V @ 11 - 15 mA
B2 supply:  22 1/2 V @ 0.55 mA
C supply:  -4 1/2 V @ 0.7 uA
I used transformers and parts on hand to incorporate
a regulated 6 volt DC supply for the filaments,
zener regulated B+ supplies, and
a regulated -5 volt C- supply.

A speaker

I found that I got sufficient audio output using a 5" speaker

with an output transformer from my junk box.
I mounted the speaker in an old wooden speaker box that I refinished.
But I would like to find a more appropriate speaker.
Any recommendations for an appropriate speaker or horn?

Finishing touches

I obtained a copy of the original battery interconnection diagram,
thanks to Tom Provost, a reader of my initial post.
This is attached to the back of the set and serves to
identify the function of the seven binding posts.
AFTER/pict0001.jpg

Here is the finished product!
AFTER/pict0017.jpg

Only the two small rheostat knobs are not original.
Does anyone have two original F-E type 385 knobs?
These are engraved 0 - 100 around 270 degrees, and are about 2 1/2" in diameter.

I really enjoyed this restoration project and learning about and listening to a TRF receiver.
Now I truly know where the expression
"Stay tuned"
comes from.

Thanks again for your help, advice, opinions, comments.

-Al

Please feel free to contact me at the address below:

w2ads@arrl.net.net

Page last modified 12/29/2005