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This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022

 

Beolit 600 Mexico

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Søren Mexico
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Søren Mexico Posted: Sun, Oct 6 2019 6:08 PM

My aunt gifted me this Beolit 600 a couple of years ago, it has been standing on my desk for a couple of years, as the antenna was broken I have been looking for the same for quiet some time, Henrik (Square4) found one in DK and gave it to me on my last visit. Thank you Henrik.

I opened it up, found some oxidation on a couple of covers, apart from some dust it looks very clean, someone has been inside there before me but solder points looks untouched.. Before opening I put the 6 batteries into it and turned it on, no reaction what so ever, will investigate when time allows

Collecting Vintage B&O is not a hobby, its a lifestyle.

Dillen
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Dillen replied on Sun, Oct 6 2019 6:31 PM

What a nice radio Smile
Check the IF-transistors. The AF116 are notoriously failing due to the tin whisker syndrome.

Martin

Søren Mexico
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Cheked some of the electrolytic caps, all checked very high, 125 uF up around 175 uF

Collecting Vintage B&O is not a hobby, its a lifestyle.

Craig
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just had to have a look at the "Tin Whisker Syndrome" fascinating really...…..

 

Søren Mexico
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I had it somewhere in the back of my brain, googled it to freshen it up. I will desolder the AF116 and measure them, then decide what to do. One site recommend to burn the whiskers with a charged capacitor. Anyone ever tried that ??

Collecting Vintage B&O is not a hobby, its a lifestyle.

Søren Mexico
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Søren Mexico:

I had it somewhere in the back of my brain, googled it to freshen it up. I will desolder the AF116 and measure them, then decide what to do. One site recommend to burn the whiskers with a charged capacitor. Anyone ever tried that ??

Found this with good explained procedures

Martin did you ever try this

 

Collecting Vintage B&O is not a hobby, its a lifestyle.

Dillen
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Dillen replied on Mon, Oct 7 2019 9:34 PM

Yes, but it will only be a temporary solution.
Before long (a week or ten years?) another whisker will reach something inside and the component will fail again.
They will all fail eventually, so I pretty much replace AF116 (and AF117) on sight.

Martin

Søren Mexico
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Dillen:

Yes, but it will only be a temporary solution.
Before long (a week or ten years?) another whisker will reach something inside and the component will fail again.
They will all fail eventually, so I pretty much replace AF116 (and AF117) on sight.

Martin

Found a NTE 160 as replacement, will that do. Martin do you have a complete kit for Beolit 600, Transistors, caps and trimmers

 

Collecting Vintage B&O is not a hobby, its a lifestyle.

Dillen
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Dillen replied on Wed, Oct 9 2019 5:19 PM

I don't have a kit for this model.
Actually, I think you are the first to ever ask for one. Laughing

I like to use AF109r for the first IF in most of B&Os germanium based tuners and something like AF176 in the second IF-stage, but these germanium transistors
are usually quite forgiving and the circuits well made and not particularly critical.
AF116 (~NTE160) will probably be fine.
As a very basic handrule; If sensitivity is lost (too low Hfe) or stations appear strongest just outside of their center frequency (too high hfe/"distortion"), the
transistor is no good for the circuit or at least its working point needs to be changed to suit.

Martin

Søren Mexico
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Thank you Martin, only my laziness forced me to ask for a kit Laughing, i will continue looking for failures before ordering new parts, when I have the AF 116 desoldered I will check and if needed try the cap trick, and if I get the unit working, change them later, I have sufficient caps and trimmers in stock to get started. Its a PIB to start up again after doing nothing for couple of years, had to read up on germanium transistors and study drawings again and again, my old brain is not what it used to be 

Collecting Vintage B&O is not a hobby, its a lifestyle.

Søren Mexico
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Going very slow here, got the battery housing out, negative pole soldered wire that goes to the on/off button, the positive side just pressed against the steel frame

Desoldered one AF116, from B C E to case measured M ohms, in my transistor tester this, right or not at least it shows a transistor

Collecting Vintage B&O is not a hobby, its a lifestyle.

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