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 Radio going off station
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 Return to top of page · Post #: 1 · Written at 9:02:37 PM on 26 July 2016.
Tallar Carl's avatar
 Location: Latham, ACT
 Member since 21 February 2015
 Member #: 1705
 Postcount: 1423

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.

Radio Chassis
Radio Chassis
Radio Chassis


 
 Return to top of page · Post #: 2 · Written at 9:14:03 PM on 26 July 2016.
Brad's avatar
 Administrator
 Location: Greenwich, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 5562

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...

 
 Return to top of page · Post #: 3 · Written at 9:42:19 PM on 26 July 2016.
Tallar Carl's avatar
 Location: Latham, ACT
 Member since 21 February 2015
 Member #: 1705
 Postcount: 1423

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.


 
 Return to top of page · Post #: 4 · Written at 11:46:32 PM on 28 July 2016.
Brad's avatar
 Administrator
 Location: Greenwich, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 5562

Photos uploaded.


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A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 5 · Written at 5:26:26 PM on 29 July 2016.
Robbbert's avatar
 Location: Sydney, NSW
 Member since 18 September 2015
 Member #: 1801
 Postcount: 1094

What valves are in this radio? I can see EAF801.


 
 Return to top of page · Post #: 6 · Written at 5:34:20 PM on 29 July 2016.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 5300

Line-up for model A23A is: ECC85, ECH81, EAF801, ECL86

Detector is an OA79 germanium diode.

Rectifier is a silicon bridge.


 
 Return to top of page · Post #: 7 · Written at 9:00:28 PM on 29 July 2016.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 3786

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


 
 Return to top of page · Post #: 8 · Written at 9:09:12 PM on 29 July 2016.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 5300

Specified as a 110/220 volt AC set.

Push-button band switch.


 
 Return to top of page · Post #: 9 · Written at 11:01:24 PM on 29 July 2016.
Robbbert's avatar
 Location: Sydney, NSW
 Member since 18 September 2015
 Member #: 1801
 Postcount: 1094

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.


 
 Return to top of page · Post #: 10 · Written at 10:55:25 AM on 1 August 2016.
Wa2ise's avatar
 Location: Oradell, US
 Member since 2 April 2010
 Member #: 643
 Postcount: 729

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.


 
 Return to top of page · Post #: 11 · Written at 8:36:21 PM on 1 August 2016.
Tallar Carl's avatar
 Location: Latham, ACT
 Member since 21 February 2015
 Member #: 1705
 Postcount: 1423

Its the AM stations. They just disappear and I just retune it to find them.


 
 Return to top of page · Post #: 12 · Written at 9:15:34 PM on 1 August 2016.
JamieLee's Gravatar
 Location: Clare, SA
 Member since 27 March 2016
 Member #: 1894
 Postcount: 501

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!


 
 Return to top of page · Post #: 13 · Written at 9:26:57 PM on 1 August 2016.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 3786

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.


 
 Return to top of page · Post #: 14 · Written at 9:50:23 PM on 1 August 2016.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 5300

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.


 
 Return to top of page · Post #: 15 · Written at 8:51:17 PM on 2 August 2016.
Johnny's avatar
 Location: Hobart, TAS
 Member since 31 July 2016
 Member #: 1959
 Postcount: 323

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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