blaupunkt: New York Vollstereo
blaupunkt: New York Vollstereo
This is my first post to this forum, so please have patience with me. I need advice to proceed further with the restoration of this type 40400 Blaupunkt New York console stereo radio and record changer. As received, it was dead and was to be disposed of as trash. Since I am a novice radio restorer, I was unsure I could repair it. It has taken me six months of study and poking at this radio to bring it to its current state-UKW band sounds excellent (I cannot take credit for this as it has been problem free from the start); MW band sounds excellent but has some buzz (normal?) between stations; KW also sounds good but I believe that it needs to have the MW band switched on previously in order to receive stations strongly. LW is characterized by a loud buzz and no stations (I can duplicate this loud buzz on MW and KW bands by placing my Voltmeter probe on Pin 2(grid) of the RF amplifier tube (EF89). Until 2 weeks ago, the radio received only UKW, the upper portion of the MW band and no KW. Using a frequency counter, I determined that the radio would stop oscillating on the low frequency end of the MW band; no oscillation at all occurred on the KW band. I found C712, a 36 Pf tubular capacitor in the oscillator circuit to be defective. When replaced, the MW band was restored and the KW also began to recive stations-however it appears that if the KW is switched on first, it does not receive as many staions as when MW is played first and then KW is then switched on afterwards.
The oscillator voltage, as measured with Heathkit VTVM and radio frequency probe is between 4.5 and 7 volts on KW; 6 to 8 volts on MW and 7 to 10 volts on LW. ECH 81 shows the following:
Pin 1: 91 volts; (schematic shows 92 volts for MW, no value for KW).
Pin 6 (mixer plate): 231 volts on MW and KW; (schematic shows 242 volts for MW, no value for KW).
Pin 8 (oscillator plate): 65 volts on KW and 108 on MW; (schematic shows 108 on MW, no value for KW).
EF89 (the RF amplifier, V702) shows the folowing:
Pin 7 (plate): 196 volts on KW and 235 volts on MW. (Schematic shows 225 volts on MW)
Pin 8 (screen): 60 volts on KW and 70 volts on MW (schematic shows 22 Volts on MW, no value for KW).
EF 89 (IF amplifier) shows 228 volts for MW on Pin 7 (plate) and 74 volts on pin 8 (screen), both are in accord with schematic.
EABC80 shows 65 volts on Pin 9 (plate) on both MW and KW. Schematic shows 82 volts, so detector plate voltage is low.
EL 84 (V706) shows normal voltages (202 on plate and 215 on screen).
Most electrolytic capacitors in this radio (in both the high frequency portion and the amplifier section) have been replaced by me-approximately 4 small electrolytics still remain to be replaced. New main filter electrolytics were installed and the selenium rectifier replaced with 4 diodes and 4 snubber capacitors as reccomended in this forum. B plus voltage is now steady at 291 volts. Can anyone provide further advice at this time?
Regards,
Robert Sottile
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volstereo
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Hi, Robert,
Your Voltage Readings are OK, so far. Most Values are stated to be + - 10% or more, others may vary by recieving Conditions ( i.e. strong or weak station tuned ).
Can You please make a Picture from the front ( Dial Glass and Pushbutton section only and load it to the Model Page ) ( You can e-mail me the picture if there is any problem )
There schould be a Button for Ferrit Antenna, which You schould try in addition to MW.
Try the following: Select Short Wave, tune to a station, and then apply little Pressure on the KW Button. There is 1 - 2mm Way left, and if You hear terrible Noise from the Speaker, while Switch is moved, then the reason is any kind of Contact Oxidation etc.
With theese Models it ist almost impossible to reach the Contacts for cleaning. I have a Blaupunkt Riviera 2540, where i removed the whole Switch Assy, removed all Cables, removed the Switch sliders, and cleaned the Contacts. It was very difficult to handle, and it is a very high Risk of breaking something.
Please keep in mind, that at the current Point, You have a wonderful Console Radio, with some minor defects. If You go further, You may be succesfull, but at a high Risk You have lost everything.
I can make Pictures of the switch Assy of my Riviera, and show You the important details, because it is currently open. Please let me know.
Best Regards from Germany,
Henning
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Thank you all for your thoughts. Mr. Oelkers I have sent you, by e-mail, a picture of the dial as you requested. When I tried to upload the picture on this site, I discovered that it is too large and have not figured out how to make it smaller so that others can see it if they are interested. I tried pressing on the KW switch button as you suggested but without effect-no loud noise comes from the speaker. I will also try today a different ECH81 to see if there is any improvement on the KW range. I am pretty sure that there is some oxidation on the band switch contacts as I found some on the UKW switch contacts which are exposed to view once the chassis is turned up-side down. It cleaned up easily with a cotton swab and contact cleaner. Is there some way to spray clean the rest of the band switch without removing the whole switch assembly?
I also engaged the ferrite antenna on the LW band (which I had not previously done) and discovered that the loud buzz disappears and stations are received. On or around the stations I can also hear what sounds like an oscillator, changing in frequency the closer one tunes to a station.
I am not sure if the switch is a problem, but I am in agreement with your advice that one can push too far sometimes and lose all. Still, I would like to see the pictures of the band switch if you have the radio still open if it is not too much trouble. I also have another Blaupunkt radio, Model "Florenz", which I purchased in order to help me restore the "New York" console and the "Florenz" seems to have switch problems, so your pictures will be quite helpful.
Can the volume control switches on these radios be sprayed with contact cleaner as on American radios? Sometimes there is noise when I turn the volume control.
Regrds,
Robert Sottile
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Hi Robert,
sorry, i have been busy all day, but i schould be able to send pictures about what i mean within the next few Days.
Thanks for Your Patience, best Regards,
Henning
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I have added the picture of the dial for others to see on the model page. Since this was successful (I think) I would add any other pictures, such as circuitry, tubes, etc. that other members might want.
Regards,
Robert Sottile
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Hi, Robert,
as mentioned before, i removed the whole Switch Assy from my Riviera.
in preparation, i made many pictures to be able, to put it all back to the right place.
The Switch Assy consist of 2 "Pertinax" Plates. They are mounted at about 8mm Distance, and all the Contacts are pressed trough rectangular holes, tha line up exactly.
Every Slider is put between the 2 Pertinax Plates, and is held in Place, by two Brass Bolts , these Bolts have Oval Holes in the Pertinax Plates.
The Upper Pertinax plate is held in Place by tiny little Clamps ( apx 10-20 of them ), while the lower Plate is sitting at the Bottom of the metal Frame.
To unassemble, i needed to remove all the clamps ( was not too complicated ), and then unsolder all Contact Ends on the upper side, and clean each Contact End from any soldering Residue. After all Contact Ends are completely flat, i could start to lift the whole upper Pertinax plate. I needed to it step by step, because the Plate is very thin and fragile, and if this Plate cracks....... So it took me about 2 Hours to work the whole plate up to have enough room, for the Brass Bolts to be free from their oval Holes, and then i was able to remove the Sliders.
I needed to mark the Sliders, because not all Sliders have the maximum of 4 Contacts, some only have 3 or 2.
After cleaning the Contacts, and checking all the Springs, i gave the whole thing enough time to get dry completely.
Then i startet to reassemble. After inserting the Sliders one by one, i started to work down the upper Pertinax Plate, while lining up all the Brass Bolts with the Oval holes. I wished to have 5 hands Minimum at this time.
After the plarte was back in the old Position, i rewired the upper Contact Ends, and then put the Assy back into the Radio.
here are some Pictures, that may help to explain.
Best regards from Berlin,
Henning
Attachments:
- Rear View at 45Deg (115 KB)
- Bottom View w Brass Bolts and Oval holes (128 KB)
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Thank you for the description of the switch disassembly and pictures. I have read your description over many times while looking at the switch in the "New York" and I now understand your procedure. I do not think that I will attempt such a repair at the present time as the danger of doing more harm outweighs the possible benefit. This was a very difficult repair to make and not one for a beginner such as myself.
Regards,
Robert Sottile
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