Radio going off station
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Location: Latham, ACT
Member since 21 February 2015
Member #: 1705
Postcount: 2174
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I have a nice Nordmende Elektra. It has all of a sudden started going off station. I would retune it and then it would lose it again. This radio has not been recapped. Would this indicate a capacitor issue? I was given it by a good friend and have had no issues till now. This set can pick up New Zealand without a outside antanae in the afternoon and holds onto it quite easily.
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Administrator
Location: Naremburn, NSW
Member since 15 November 2005
Member #: 1
Postcount: 7395
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This radio has not been recapped. Would this indicate a capacitor issue?
I'd put money on the condensers being at least one of the causes. Years ago when I started to adopt the practice of recapping receivers I was encouraged by this symptom. I did a full electro and paper-cap replacement and the problem stopped.
If you recap this set, be prepared for the extra complexity of European radios, and far more components than Australian ones.
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A valve a day keeps the transistor away...
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Location: Latham, ACT
Member since 21 February 2015
Member #: 1705
Postcount: 2174
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I just looked inside it and yep its all original. so I will give it a good going over. Yes I agree Euro sets can be complex but they can also be user friendly as well.
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Administrator
Location: Naremburn, NSW
Member since 15 November 2005
Member #: 1
Postcount: 7395
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Photos uploaded.
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A valve a day keeps the transistor away...
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Location: Hill Top, NSW
Member since 18 September 2015
Member #: 1801
Postcount: 2078
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What valves are in this radio? I can see EAF801.
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Location: Sydney, NSW
Member since 28 January 2011
Member #: 823
Postcount: 6761
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Line-up for model A23A is: ECC85, ECH81, EAF801, ECL86
Detector is an OA79 germanium diode.
Rectifier is a silicon bridge.
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Location: Wangaratta, VIC
Member since 21 February 2009
Member #: 438
Postcount: 5389
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ECL86 /6GW8 probably audio output Triode Pentode Audio
EAF801 Remote cut off RF / IF Pentode with diode IF amp & may use diode for AGC
ECC85 RF mixer / Amp FM Double Triode (6AQ8 B719)
ECH81 Triode Heptode Prob AM mixer.
With a silicon bridge rectifier watch the voltages of the filter caps. These are similar to filament rectifiers as they create a surge voltage prior to valve conduction. With a 250V "B" voltage that can get close to 500V & modern caps do not specify a surge voltage only a working one.
If that has a transformer, make sure it is set on 250V not the European 230V. (Some European sets have no mains transformer, and that which looks like one can be a choke rendering the PC board "Alive": Beware
Marc
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Location: Sydney, NSW
Member since 28 January 2011
Member #: 823
Postcount: 6761
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Specified as a 110/220 volt AC set.
Push-button band switch.
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Location: Hill Top, NSW
Member since 18 September 2015
Member #: 1801
Postcount: 2078
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Europeans love their push-button sets, that's for sure.
ECC85 (FM mixer/amp) can be replaced by a 6ES8 for added sensitivity.
Never seen a EAF801, the others are fairly common.
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Location: Oradell, US
Member since 2 April 2010
Member #: 643
Postcount: 831
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Is it FM stations drifting? If there's an automatic frequency control circuit, it might be broken. Maybe a bad cap? Or a dirty push button piano key selector switch? Those European switches are famous for getting dirty and making poor contacts.
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Location: Latham, ACT
Member since 21 February 2015
Member #: 1705
Postcount: 2174
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Its the AM stations. They just disappear and I just retune it to find them.
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Location: Clare, SA
Member since 27 March 2016
Member #: 1894
Postcount: 510
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My Blaupunkt New York did that, prior to the AM not working at all, it was infuriating as I had to jump up and re-tune it every 5 mins.., It would give me a nasty tingle if I touched the antenna and started popping fuses, it still works on FM, but only just... Knowing what I know now, from being a member of this forum, I am very sure it would be dodgy capacitors. I will replace mine, before attempting to use the radio again, I suggest you do also as these problems only get worse, never better! It sounds like you have a real gem of a radio there!
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Location: Wangaratta, VIC
Member since 21 February 2009
Member #: 438
Postcount: 5389
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It would be interesting to know if the Blaupunkt has a transformer? Many European sets (as I have noted) do not. Sometimes there is a cap from mains to chassis as an earth return for RF: It should be on Neutral. Therein lies a problem. There's a 50/50 chance its not and that can affect reception.
On some there is a cap in series with the external antenna connection if its primary coil is not floating. In both cases they should be a mains approved line cap (X/Y).
The other way to get bitten with transformer sets is line caps going to an non-grounded chassis, or having a shielded transformer on same.
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Location: Sydney, NSW
Member since 28 January 2011
Member #: 823
Postcount: 6761
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They just disappear and I just retune it to find them.
Most likely cause is oscillator drift. Usual suspects: capacitors; possibly a weak mixer valve.
Start with a re-cap, then check voltages.
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Location: Hobart, TAS
Member since 31 July 2016
Member #: 1959
Postcount: 563
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I'm new here, so I hope I'm not treading on toes.And no idea of the original posters talent or knowledge.
I have not got or can see a circuit, but from experience firstly give the ECH81 a tap with an insulated tool.
Or just replace it if possible. 6AJ8 direct replacement without affecting alignment too much.
If that doesn't fix it check carefully caps off pins 7,8 and 9 of the ECH81 which I believe is the oscillator section.
Also check any caps off pin 3 the cathode.Freeze spray used to be the go 30 years ago for these sort of problems.
Be careful not to spray onto hot valves!!!. If using this approach.
Also some of the caps may be hidden within the osc coil can, which should be off one of the pins mentioned.
Cheers, JJ
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