Ukw.E.d1 RESTORATION WORK

 

NEED SCHEMATIC

 

The Ukw.E.d1 is a very interesting receiver in that it's essentially the E16 receiver from the FuG-16 transceiver of single-seat fighter aircraft such as the ME-109. The E16 has been modified for operation in a Befehlspanzer (command tank). The modifications include the addition of frequency-tuning mechanics, change of control panel / face-plate, and the removal of rack-mounting hardware. The receiver has also been placed into a Panzerholz enclosure for mounting in a tank.

The purpose of the Ukw.E.d1 is to be part of the Fu7 system, along with the 20W.S.d transmitter in a special command tank with the purpose of communicating with aircraft.

About this receiver:

  • 1941 construction. Becasue of the early date of this receiver, it is very very light. This is perhaps by far the lightest receiver in my inventory.
  • It has a serial number 10073, which may indicate it being from the earliest production run of these models.
  • From examining other examples of thie receiver, the serial number can be found at least in two other places other than the manufacturer's data plate: On the inside of the panzerholtz case, the reverse of the fine-tuning control knob, and on the reverse of the frequency dial.

Issues with the receiver:

  • Power wired incorrectly, and inconsistently. +12 volts appears on the negative tube terminals, and -12 volts appar on the positive terminals. When all three modules are combined together, there is a short somewhere between the + and - of the filament circuit.
  • Grounding is not effectively maintained throughout the receiver. Grounding attachments are made on the reverse of the front panel, but the front panel does not have a consistent connection to the intermediate chassis, and therefore the modules.
  • The "Fern/Nah" antenna switch is not working.
  • The frequency scale, although original, has red lettering drawn on it by hand.

To summarize, most or all of the receiver is there, and in great condition.

Goals of restoration:

  • Repair the incorrect power distribution of the receiver.
  • Repair the Nah/Fern antenna switch.
  • Perform general maintenance:
    • Clean contacts
    • Repair wires and cold solder joints
    • Reinforce weak rivets
    • Establish close-to ideal grounding between modules
    • Clean and lubricate mechanics
  • Restore damaged vacuum tubes.
  • Test receiver for proper frequency range function.
  • Restore the scale to the original graphic of frequencies.

 

 
 

 
One of the problems immediately encountered was with proper grounding. The primary grounding connections were actualized with bolts connected to the front chassis of the receiver. This front chassis mounted the face-plate, control panel, and the intermediate chassis, which accepted the central tuning module. There was massive resistance for the filament power. Artificially connecting the ground, as shown in this photo, fixed this problem,

 

 
Here the female connector for the IF and LF stages, which has been detached and is being tested to understand the connection problem.

 

 
 

 

 
Cover removed from the reverse of the IF and LF stage module Note the typial Spritzguß construction.

 

 
HF and heterodyne module with the cover off.

 

 
 

 

 
Below is the power connector filtering electronics, along with the power switch and the volume control. When 12-volt power is provided, a relay is activated at the Umformer, which then sends 120-140 volts to the receiver. (St 3) is the side-tone connector to the transmitter (20W.S.d), and below that are the headphone terminals.

 

 
Reverse of the voltmeter. Both the filament and anode connections travel through the voltmeter first. The filament reading works, while anode one does not at this time.

 

 
The other side of the HF and heterodyne block module. The tank circuits seen in the photo belong to the mixer and local oscillator.

 

 
Front knobs and panel are removed. The scale is original, but has been modified with text written in red ink. Before this can be erased, the receiver must be tested for the correct frequency.

 

 
Closeup of the modified scale.

 

 
Scale has been removed, showing the mechanics. Note the frequency pre-set spring on the main cog-wheel.

 

 

Frequency dial removed. Based on these markings. It may be assumed that the frequency range has not been tampered with. The date of "14 11 41" is another data point indicating 1941 manufacture.

 

 

 
Reverse of the frequency dial showing the serial number of the receiver 10073, which is also repeated on the inside of the case, and on the reverse of the fine-tuning knob.

 

 
Closeup of the machanics.

 

 
Closeup of the machanics.

 

 
Above the mechanics are the contacts for the 12-volt light-bulb. The wires have been cut and have to be replaced.

 

 
Early Waffenamt stamp

 

 
This is the grounding stub for the antenna "Fern/Nah" switch. When it's switched to "Nah", the antenna connector gets connected directly to ground.

 

 
Reverse of the antenna connector along with the grounding tab.

 

 
In the middle of the photo is the hole through which the "Fern/Nah" activation rod is inserted.

 

 

Here is the reverse of the "Fern/Nah" switch. There are two such surfaces depending on the position of the switch. They differ by 1.5mm and allow for the pushing of the rod against the grounding tab.

 

 
Since the original tab was missing, this one was machined out of a screw.


 
A loose wire was mended.

 

 
Another photo of the HF and heterodyne block.

 

 
Top of the HF/heterodyne module.

 

 
 

 

 
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