Старый тюнер Pioneer
Доброго времени суток!
Попался мне вот такой вот тюнер http://www.hifi-pictures.net/tuner/P...551L/tuner.htm
Красивый и хорошо вписывается в систему, но работает не очень. В режиме моно вроде бы нормально, а вот стерео ловит на 0,1мгц больше положенного и правый канал громче. Есть подозрения что это все от старости, т.к., по тщательному осмотру, к винтам крышки не прикасались.
Итого вопрос: попытаться починить или же отправить его назад?
PS завтра еще попробую созвониться с СЦ, интересно что они скажут.
PPS документации на аппарат не нашел
---------- Добавлено в 23:39 ---------- Предыдущее сообщение в 23:20 ----------
нашел еще вот такой текст, но я не все понял:
http://www.fmtunerinfo.com/pioneer.htmlOur contributor Brian Beezley offers this review: "The Pioneer F-551 is a small, black, synthesized AM/FM tuner. It has 24 presets in two groups of 12, three-speed manual/automatic tuning, and a novel adaptive RF-alignment system. The rear panel has thumbscrew antenna terminals, wired remote control jacks, and a switch for 9-50/10-100 kHz AM-FM channel steps. Pressing a button momentarily displays signal strength as a single digit. AM covers the extended band to 1700 kHz. Inside I found what at first appeared to be a basic tuner circuit, with two RF tuned circuits in the signal path, two IF filters (280 and 180 kHz), and a single-tuned quadrature detector. The tuner uses a 2SK241 RF amp, HA11225 IF amp/detector, AN7470 stereo decoder, LA1247 AM chip, LC7217 PLL, and M5223 varactor driver op-amp. There is no pilot cancellation or supersonic filtering.
"I wondered what the CCTS function did. Enabling it and poking around with a scope, I discovered that the tuner scans the RF-amplifier varactor voltage over a small range whenever the tuned frequency changes. It then uses the voltage that yielded maximum signal. I intentionally misaligned the front end and found that CCTS very effectively restored proper tuning. After I carefully reset the alignment, I was impressed that CCTS was able to slightly improve it. In addition to correcting a sloppy factory alignment, CCTS can compensate for temperature variation or component aging. CCTS is fun to watch as it displays signal strength before and after adjustment. It takes a second or two to operate, so you can disable it when you want to tune across the band more rapidly. You can also leave it off if you don*t tune weak signals.
"I replaced the IF filters with matched 180 kHz Muratas. 1 kHz stereo THD was about 0.15%. The front end has no trimmer caps or inductor slugs, but the coils are easy to deform with a plastic tool. I was surprised to find that sensitivity was 2-3 dB higher than what I normally measure for most tuners. With the 180s installed, HD Radio self-noise was not objectionable. I heard a little background noise on a couple of strong signals, an indication of RF intermod in my high-RF location, but it wasn*t all that serious. Some high-end tuners I*ve tried performed a lot worse." The F-551 can be found for less than $50 on eBay.
Сообщение от Elms
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