|
Who's Online
There currently are 5668 guests online.
|
Categories
|
Information
|
Featured Product
|
|
|
|
|
There are currently no product reviews.
;
The document was usefull, and it was exactly what I was looking for.
;
OK?..manual is complet and helpfull... for repairing such a old and rare boombox like JVC PCM it is necessary...
;
Super Anleitung. Ordentliche Auflösung. Das ganze noch in Deutsch wäre zu schön. Alle Datenblätter sind sauber Kopiert und alle Leitungswege sind sauber ausgeführt
;
Thanks God for the internet and thanks for the service like this - proffessional solution on time.
;
About the service it's very fast and reliable. About the manual the quality is high enough to read even the tiniest details on the wiring diagrams so you can't ask much more than that, let it alone for a manual of a product from 20 years ago. Thank you, very satisfied.
5-2 Receiver Section
LOW NOISE AMPLIFIER (LNA, Q302)
The low noise amplifier amplifies a weak signal received from the base station to obtain the optimum level (Noise figure = 1.5 dB, Gain = 16 dB).
IF SAW BAND PASS FILTER (FOR CDMA)
IF SAW BPF (F303) is used for CDMA system having 1.23 MHz wideband and 630 kHz bandwidth. The filter also attenuates the image product generated at the mixer.
RADIO FREQUENCY BAND PASS FILTER (RF BPF, F302)
The RF BPF accepts only a specific frequency (881 12.5 MHz) from the signal received from the base station. The band width is 25 MHz.
BUFFER AMP (Q304)
Buffer (Q304) amplifiers signal to be applied to the local input of the down converter (U301) when a phase is locked between VCO (U341) and PLL IC (U342).
DOWN CONVERTER (MIXER, U301)
First local signal is applied to this down converter. The down converter transfers the signal amplified at the LNA into 85.38 MHz IF signal. 85.38 MHz IF signal is made by subtracting 881 12.5 MHz RF signal from 966 12.5 MHz first local signal.
AUTOMATIC GAIN CONTROLLER (AGC) AMP (Q302)
85.38 MHz IF signal is applied to IF AGC amp, the IF AGC output level is applied to BBA (Baseband Analog ASIC). The IF AGC amp (Q302) keeps the signal at a constant level by controlling the gain. Dynamic range is 90dB, up gain +45dB, and down gain -45dB.
5-4
|
|
|
> |
|