Thank you for your Help!!

[Lighting]

Well, I have recently composed a radio using CXA1019S(a product of
Sony),However, the radio cannot receive the FM signals(It accually
receives the noise), thought I have examed all the solder points and
they are all well soldered. Please give me some suggestions on how to
quickly exam where was wrong. If not, as a amateur, please tell me the
detailed methods to find the wrong area.(the tools that I only have
are an oscillograph and a multimeter)
Thank you for your help!,I am really anxious.

 

[Charles]

"Lighting" <111Yi.Jiang@gmail.com> wrote in message
news:9c7c722e-512c-4e65-b4bd-7922a606039f@s8g2000prg.googlegroups.com...

Well, I have recently composed a radio using CXA1019S(a product of
Sony),However, the radio cannot receive the FM signals(It accually
receives the noise), thought I have examed all the solder points and
they are all well soldered. Please give me some suggestions on how to
quickly exam where was wrong. If not, as a amateur, please tell me the
detailed methods to find the wrong area.(the tools that I only have
are an oscillograph and a multimeter)
Thank you for your help!,I am really anxious.

If you are trying to receive FM signals in the 88-108 MHz range, then be
aware that the oscillator in your circuit must mix with the incoming signal
to produce a difference of 10.7 MHz. Thus, you can use a working FM
receiver to determine if the oscillator is working. For example, if the
non-working receiver is set to 90 MHz, then the oscillator should be 10.7
MHz higher in frequency (100.7 MHz) and you can tune to that frequency with
the working receiver placed close by to determine if that signal is present.
The working receiver will show some activity such as quieting or a "dead
carrier" if the signal is present.

Your oscilloscope might not be capable of displaying the oscillator signal
or might load the circuit and prevent oscillations.

Google for "superheterodyne" to get more information.