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Beomaster 3000-2 refresh

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Ninni
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Solna, Sweden
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Ninni Posted: Fri, May 29 2020 8:12 PM

Hi all. I have a Beomaster 3000-2 in pristine condition that haven't been used in many years. It looks like it hasn't been used much but I know nothing about previous owner(s).

What do you recommend to do, to take it into use? Should I plug it in and test it before replacing any parts or should I replace capacitors before attempting to power it up? I have the necessary capacitors at hand.

Dillen
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Copenhagen / Denmark
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Dillen replied on Sat, May 30 2020 6:12 AM

Check the condition of the three large capacitors before powering up. They are the ones capable of causing the most problems/damage.
Power up slowly on the variac without speakers, while keeping an eye on the mains current. If things look wrong, power down immediately.

It's safe to say, that all Beomasters of this series will be in need of a thorough restoration by now.
A convenient and quite extensive service-kit is available for this model, containing new components for all board-mounted capacitors, tantals, trimmers, lamps etc.  PM or email me.

Martin

Ninni
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Ninni replied on Sat, May 30 2020 5:16 PM

Thank you for your reply Martin. I don't have a variac, but I'll see what I can do.

Ninni
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Ninni replied on Tue, Jun 2 2020 8:28 PM

I decided to replace the four large caps before attempting to power up.

Then I connected a lamp holder in series with the mains and tried first with a 40W bulb. This seemed ok, so I replaced it with a 60W bulb. Still no signs of anything wrong, so I switched to a 100W bulb. Still no trouble in sight, so I connected a pair of Beovox CX50.
The radio played with a nice clear tone. No sound in right channel but pressing the speaker selectors a couple of times cured that.

Since everything seemed fine, I removed the lamp and connected the Beomaster directly to the mains. Still nothing obviously wrong. The cooling finns for right channel gets somewhat warm after a while, so I should check quiescent current.
The sound from the radio is wonderfully clean and the pots DONT EVEN SCRATCH! Even the lamps work, except for one of the tuning balance lamps. I replaced that, so now everything works, as far as I can tell.
The supply voltage measures 55 volts instead of the specified 60 volts. I set the mains selector to 240 volts, since we have 230 volts mains nowadays. So maybe this explains it.

Ninni
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Solna, Sweden
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Ninni replied on Thu, Jun 4 2020 4:46 PM

I have now replaced all aluminium electrolytic caps with new ones, with one exception: There is a 5 µF cap in series with the phono 1 input. I replaced those with polyester caps. Electrolytics in the signal path of the phono signal don't seem like the height of HIFI to me.

The idle current of both power amps was too high. I trimmed to the specified 100 mA. Now the heatsinks don't get more than lukewarm.

I trimmed the control voltages for the station dials but the MHz scale still don't match the actual station's frequency very well. Maybe something can be done about it but I don't want to tinker too much with the radio, since it works very well, apart from this.

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