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Restoring a Volksempfnger VE 301 GW (Nazi people's radio) This is a piece of history - not a promotion of Nazi ideas!!

Extracts from this document...

Introduction

Restoring a Volksempfänger VE 301 GW (Nazi people's radio) image00.png 
This is a piece of history - not a promotion of Nazi ideas!!

For all other old radio enthusiasts I described detailed the restauration of the electronics/mechanics. Additions/corrections welcome.

0 - Remarks

Don't connet a set to mains that was out of use for years/decades- You can destroy parts that are hard to find (x-former, rectifier...)

This x-formerless sets and even some sets with x-former have mains voltage on chassis !! Danger !! Use isolation x-former if available

Never short the fuse!

Get a copy of the schematic VE 301GW and a tube manual explaining the pinout of tubes."GW" means Gleichstrom/Wechselstrom = DC/AC set without mains x-former.
 

Another schematic allowing you easier understanding of the power supply. Each tube's filament needs 55 volts/0.05 amps=1100 ohms when hot. There are the 3 tubes + the 1100 ohms resistor all in line at 220 volts mains. Like most x-formeless sets the plate voltage is rectified directly from mains. That means the plate voltage depends from mains voltage (after the choke approx. 205 V = at 230 V~ and 100 V = at 110 volts~ resp.) You get the maximum performace when operating at 220/230 volts. image01.png

For another restoration project see my Loewe Opta set from 1955.

For a comprehensive overview of the other VE 301 types see Joachim Herzig's page .or Klaus' page

Very comprehensive FAQs see Phils FAQs, about the restauration of American sets see Phils Radio Wrinkles.or Oregon car radio restoration

Take notes of everything you dismantle. Without schematic and without notes you are lost!

Recommanded: a gauge for measurement of capacitors. Experience: 99% of all pre-war paper caps are bad, especially when the set was stored under high humidity conditions and not in use for several years. Ceramic caps usually have no problem if not mechanically broken.

...read more.

Middle

image09.png

I filled the old tubes with new axial type caps:

for the 60 cm/pF ...two ceramic caps of 120 pF/500 V= each in series (in order to give exactly 60pF/1000V= /as modern part not available)

for the 150 cm/pF ...a ceramic cap 150 pF/2kV=

for the 4000cm/4nF ...a 3.9 nF /630 V= Philips axial PP type ( I did't feel very comfortable with this one, so I tested this part with 450 V~ overnight - and it survived)

for the 5000cm/5nF ..a 4.7 nF / 1500 V= axial PP type

If the mains plug is inserted the bad way the chassis has mains potential ! The 4nF and 5nF caps connect the chassis to the RF ground connector and antenna connector. So these parts are safety relevant and must withstand mains voltage when ground connector is grounded or antenna is touched with hands. image10.png

These static caps don't have "+" and "-" like electrolytic caps. Most static caps have a marking on one side. This marks the outer layer of both foils and should be connected towards the chassis. Connecting the wrong way can produce hum in some cases.

6 - Loose grid caps or tube sockets

Unsolder all wires of the socket. Use vacuum pump to remove the liquid solder. Sometimes the wire on top of the tube is broken, then carefully file off a bit from the glass and solder an extension wire. I use 2 component glue that can withstand higher temperatures. After the glue is hardened solder the wire connection.

7 - Missing shielding laquer of tubes

The shielding laquer of these old tubes is often very brittle or already fallen off. There is a wire between glass and socket connecting the shielding laquer to the shield pin. I used a mixture of Zappon laquer and graphite powder.

...read more.

Conclusion

Unsolder all wires of the socket. Use vacuum pump to remove the liquid solder. Sometimes the wire on top of the tube is broken, then carefully file off a bit from the glass and solder an extension wire. I use 2 component glue that can withstand higher temperatures. After the glue is hardened solder the wire connection.

7 - Missing shielding laquer of tubes

The shielding laquer of these old tubes is often very brittle or already fallen off. There is a wire between glass and socket connecting the shielding laquer to the shield pin. I used a mixture of Zappon laquer and graphite powder. That worked well but the surface is a bit rough and the colour is grey. Later I learned there should be electrically leading laquer spray available from "Contact Chemie". I have not yet tested that. image11.png

8 - Revision of tuning capacitor

The tuning cap is operated indirectly from the tuning knob/shaft. The small double spring wheel on the tuning shaft grabs the large wheel (= dial) from front and rear. I cleaned and lubrified the tuning cap with Ballistol non-sticking weapon oil. After installing the cap it still did not work properly because the distance of both shafts was a bit to large. The only way of reducing the distance was to press down a bit the chassis where tuning caps sits. After this precedure the tuning worked perfectly smooth now.

9 - Repair of filament resistor

When I tried to repair the loose wire by moving the brass clamp the clamp broke. And 2 other clamps had small cracks. Very bad wartime material. I decided to re-manufacure the clamps from pieces of brass 5 x 0.5 x 100 mm all handmade. I could the reuse the old resistor wire and fix the clamps in the right position. The resistors value is 1100 + 400 ohms/ 0.05 amps and a separate section of 150 ohms/ 0.1 amps.

10 - Cleaning and testing all parts before reassembling

Now you find out why it was important taking notes!

image02.png

Available parts/ scrap chassis /Schrottchassis image03.png 
 
   

...read more.

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