AUX and smartphone in cigarette lighter

Smartphone works nicely with Blaupunkt SC 202 car radio DIY AUX but hiss is pronounced after 50+ volume level. It’s not big deal, because I don’t listen louder than 50% in car. Outside one don’t hear any hiss at all. Some people recommend to change capacitors on amplifiers but I decided to leave as it is. According to LCR-T4 old capacitors have high ESR but acceptable. To get less hiss, turn high volume on phone and low volume on car radio. Old cheap phone produces more hiss comparing with modern one.

When phone is charging in cigarette lighter, sound becomes distorted. Is it so called GND looping? Tried additional GND cable from car body to car radio, but it made no difference. Ideally I need to GND cigarette lighter same way as car radio. It’s pain...

Phone usually is charged 100% and it won’t discharge much in 4 hours, so I can live with this. As alternative I can use mp3 player with AA battery. Anyway task is accomplished – preserved original radio and added new functionality.

LFP Li-Ion LiFePO4 акумулятори

Вибираючи акуми, завжди шукаєш найнижчу ціну та найвищу якість, але чудес не буває. Багато спілкувався з китайцями. Переважно ухиляються. Все в них A grade. Траплялися приємні випадки — відмовляли від покупки говноакумуляторів, пояснюючи, що й як.

BMS для LiFePO4 батарей

Довгий час користуюся LiFePO4 батареями 6A-25A та не заморочувався BMS. Такі батареї відносно дешеві та в разі чогось їх не дуже шкода, а відповідна BMS коштує. Розбіги були незначні. Що там розбіги?! Ніколи не міряв опір банок і не зважав на здуття. Щоб витиснути з батарей максимум, потрібні мінімальний опір провідників та якісне з’єднання, але навіть 16 мм кабель створює незручності, що говорити про товщі. Краще починати з 24В, а не з 12В, якщо навантаження понад 1 кВт - економія на BMS і дротах - хоча як DYKB або ще яка дешівка... Отримали +90% ємності - батареї нові, а -80% - старі.

Blaupunkt SC 202D (C) repair, AUX

Backlight is not working properly. Some lamps do not light at all, some from time to time. Few capacitors leaked near cassette mechanism. Pronounced hiss in speakers above half volume range. Amplifier becomes very hot and distorts sound on high volume when playing from cassette adapter. Need AUX to play music from phone, because adapters and modulators suck as hell.

Audi 80 B4 Nokia rear bass speakers repair

Our problem – rotten wires under isolation. Even engineers fuck things up pretty well. Too much is done for improvement with opposite result.

I took wire of same diameter from old auto cables, connected with terminals and soldered.

https://www.drive2.ru/c/510655257332679422/ - Audi 80 B4 задние динамики

Audi 80 B4 rear door panel disassemble

This door panel is disassembled for the first time. I broke 8A0 867 725 window frame rubber, but I’ll put it back with a glue. Old rubber parts tend to break very easily. Door is in great shape. Little corrosion on window raiser lever and treble speaker cable fastening. Window winder crank handle was the hardest to remove. Take your time and do everything slowly. Installing lock door handle is challenging, but try to put it half size below it's socket to fix the hook. Use long magnetic screwdriver to fix lock door handle. Foam rubber is a disaster...

Blaupunkt SC 202 D (C) audio system on Audi 80 B4

Problem: rear bass speakers do not work, treble speakers work.

That’s what you get, when savages repair your car: