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Technic(s) works (still in progress)

2011/03/28 Posted by UL

Lunch break was spent assembling one tonearm from three – one was with broken off counterweight, another with damaged microlift… finally, the tonearm assembled , in place, secured, turntable assembled. All we need is to attach the pickup, make tonearm adjustments, and – that’s it!

Uh, doh, forgot – the dust cover! But that is the last item.
More pics.
Regarding the second Technics – I decided to repaint the body of the turntable as the 34 years of age were clearly visible. All the lettering was scanned in high res, appropriate fonts were matched. Decent silk screen services in Riga, anybody?

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Tags: SL-1500, SL-1510, Technics
Categories: Techno

Technics SL-1500 / 1510

2011/03/14 Posted by UL

The pics are @picasa, as always.
The practically identical SL-1500/1510 both suffered from the Parkinson of drive speed stabilizer circuit. It couldn’t remember the correct speed. So, a number of replaced caps later…

There is another PCB with original caps still onboard. Only one replaced by new Long Life RIFA is the ripple filter 470uF cap.

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Tags: SL-1500, SL-1510, Technics
Categories: Techno

Zudusī Zaķusala

2011/02/25 Posted by UL

Skatos te www.zudusilatvija.lv;
Ar to rodas jautājums: Ir kādam pirms-LTV un pirms-Salu tilta materiāli par Zaķusalu? Foto? Kuģīšu satiksmes grafiks? Ziņojiet komentāros!

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Categories: Kraukļa krājumiņš

Politikas aktualitātes

2011/02/22 Posted by UL

Runā, ka valdība drīzumā atkāpšoties, bet turpināšot strādāt līdz vēlēšanām, lai pabeigtu iesāktos darbus!

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Categories: Politika, Savādi gan

Some SONY designs sucks!

2011/02/19 Posted by UL

When you come across a particular device where all the transistors in one channel are blown, you may to start wonder – why?
A little later — when you have replaced them all with new ones, you discover – the problem is high frequency oscillation. Amp effectively becomes the VHF generator – for a short time.
I see the problem being the two stages of amplifier built on two separate PCB, connected with a kind of PCB bridge. 2 x 16 contact pins – all of them losing contact due oxidation sooner or later. See the attached pics and schematics. High-voltage circuit, ground and feedback loop – all are connected via the same PCB bridge. No wonder the result is fatal if something goes wrong or contact is lost due oxidation.

: The vertical line separates, in fact, two PCB boards.

: Ripple filter caps, power amp module, view from top

: PCB connector from input to power PCB (other side)

: PCB connector from input to power PCB

: Input stage with voltage amplifier

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Categories: Techno

WTF is that?

2011/02/15 Posted by UL

This was supposed to be a 0.01uF capacitor. Is it?

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Categories: Savādi gan, Techno

SONY receiver ready to (receive) rock!

2011/02/11 Posted by UL

As always, more high res pics available at Picasa

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Categories: Techno

SONY receiver STR-343L – Works in progress pt.2

2011/02/08 Posted by UL

Tonight I started the assembling of cleaned and repaired receiver. Both power amp section and tuner section works well. It delivers 15V RMS on 6.8Ohm dummy load without any clipping. U**2/R produces 33W of pure RMS power, not “DIN” or “musical” or other mystical PMPO kilo-Watts…. It is pretty decent for such a small piece of equipment. So, dials, LEDs, bulbs, new caps for ripple filter and in power stage audio circuit are in place, final tweaks tomorrow. Gosh, I forgot to check phono preamp section. Well, tomorrow, as well.