nordmende: Nordmende Othello Stereo 3/616
since everything is all right. All wiring diagrams are correct
C135 / 1800pF is in the shielding cup, see it in the picture.
Please make a picture of the model/name plate that shows D320 and upload it to the model.
Thanks for your reply.Any idea how to remove the can of the Second IF transformer(Ubertrager) where the C135 is..
Maurice De Wilde
Why do you want to open the can? It is fixed soldered.
You will find the soldering spot for C135 on the bottom.
Look at the picture.
I want remoce the IF(ZF) can to remove the 1800pf Deemphasis capacitor as preamble to install the ready made Stereo decoder ex Ebay Canada,it is forwarded from China.I have made now a 12 volt power supply with a LM7812 IC regulator..For the stereo decoder to work properly,this 1800PF capacitor has to be removed.I had a look at the Undewrside of receiver.The IF can has 1 or 2 lugs that are twisted and soldered.It means using a 30 watt or more soldering iron,heath up solder very quickly and at same time twist the lug to make it straight,then when this is done warm lug again and slightly move the can on the side where the lug has been warmed up.it is an operation where you need 10 hands.Then repeat for the other lug.Can should come off to remove 1800pf capacitor.This operation is not something that you should do in an instant.it has to be thought over.
This Nordmende radio,I got from Ebay Germany for Euro 26,to ship to West Australia,I wrote to the seller in German,usually when you ask the seller in their own language they are more willingly to sent it to far places.One other seller wrote me "Es ist nicht gerade um die Ecke".
This radio was offered as defect for a "Baestler".Once here I checked on a lower mains voltage,The HT voltage was 200 volt ,should normaly be 280.Out goes the Selenium rectifier,in goes 4 1N 5408 1000 volt 3amp rectifier diodes.Added 150ohm 5 watt resistor to bring the HT voltage down to about 285 volt.The common Cathode resistor of the two EL85 final penthodes was heating up,also the elco here showed a bulging + side.Drew to mutch currewnt.Culprit,the 2 ERO 10nF capacitors going to the grid of the 2 EL85,showed a + voltage on the side of the EL85,sTook caps out,measured with digital multimeter on 1Mohm range.Showed leakage.I also do not like a common cathode resistor for the 2 EL85 final penthodes.
By now everything works OK.
To concxlude I noticed that the earlier Nordmende radios showed a better finish of cabinet.For example,the plastic buttons for Stereo,,,Bass..Solo..Jazz are surrounded by a copper/gold colour surround.On the later Tannhauser CH 4/633 I bought in 1963 in Munich, in the earlier Othello CH 3/616 this has gone.Also the scale layout has a better finish.
Later non I want to upload the Tannhauser and the finished Othello.
Maurice De Wilde
I have now removed the can of the 2nd IF(ZF) transformer.Was easy ,just heat up one side of the can lug and twist it to make straight ,then the other side.Removed the 1800pf capacitor,slide the can back in and resoldered the two tags.Iow soldered the capacitor to the removable 9 pin plug that fits the socket on the roght hand side when viewed from the back.This plug shorts the output coming from the ratio detector and the left and right channels if no stereo detector is connected.I just have to solder the left and right channels coming from the stereo detector and the input cable of the stereo detector to the removable plug and remove the shorts on the plug.
OK, you will be reporting how it works.
best regard WB.
There must be many Nordmende and other similar radios that are Stereo ,but only Stereo when playing records or tape recorders.For full stereo you need a stereo decoder.There is a source of decoders,see my attachment.Ocasionally on Ebay Canada there appear these decoder,specially made for Valve type radios..The decoders are sent from China.However you have to be quick to buy one.It is only from time to time these decoders come up.I bought three of them.To connect:
-Radio has to be wired for it,thus marked as stereo.
-Deemphasis capacitor, for Nordmende radios 1800pf capacitor,this one has to be removed.This capacitor is either located inside the second IF transformer can or later on soldered to the stereo adapter socket usually for Nordmende radios on the right hand side of the radio seen from the back.
-You need a 9 to 12 volt DC power supply or a 9 to 12 volt battery.
-Connect the output of the ratio detector to the input of the decoder,this socket on the decoder is yellow also marked INPUT.Connect to pin 4or 5 of the socket of the radio where the decoder is connected to
-Connect right and left audio outputs,sockets,red and white in colour and also marked Right and Left output.Connect these to the pins 2 and 3 of the socket where the decoder is connected to on the side of the radio,here Nordmende.
Later on when everything works ,I intend to upload details and pix.
On my Nordmende Tannhauser radio,this one has a stereo decoder connected,originally was a project of Electronics Australia.Here I expanded by adding a transistor driven relay that switches on the STEREO globe on the Nordmende Tannhauser,earlier stereo radios did not have this rtereo globe.
I have now the Stereo detector ex Ebay Canada connected.I opted for a small transformer ,output 15 volt 150ma, this gives after the LM7812 regulator 12 volt DC.I mounted the 4 1N4004 diodes and 2000MF 35volt on tags simply soldered on top of transformer.The transformer is soldered to the side of the radio chasis,that bway I do not drillo any holes on the Nordmende Tannhauser or Orthello.I still have to find a way to mount the decoder inside the cabinet..Now when you look at the schematic of the Tannhauser or Othello,they show the connections for the socket at the right hand side of the Tannhauser/Othello.It shows 2 connections to connect the Ratio detector output,either via socket pin 4 or 5.Pin 5 connect the detector output via R134 22Kohm or via pin4 bypassing this resistor.You only do this when there is not enough outut voltage coming from the ratio detector.
Also I always get confused on the schematic of the connection layout of the socket.On the schematic ,the pin sequence as shown 1,2,3 etc is actually when shown from above the plug is actually 9,8,7 etc.On the stereo decoder I did not had to touch the Separation control.Only the Input sensitivity I had to adjust.When there is a stereo transmission the LED on the decoder lights up.
I use these Nordmende radios to listen to the audio coming from the satellite receiver here via a UKW
Crystal controlled transmitter.Here nin Australia you can do this as long that the output is 10Microwatt or less.Enough to go over a 100 metres far..The Satellite dish is 3 metre with actuator(motor) to turn the sat dish to 9 satellites.I watch mainly TV from NL-B-F France 24 Monde -TVcinq,they show in the morning CH RTS tv-SP-PORT- Malaysia tv-Singapore tv- and many more ,also many radio stations in stereo.Thus it is a marriage between vintage technology and newer technology.
I am forwarding 2 pix of Othello with Stereo decoder