Hello, I have a Technics sa 202 receiver that is quite when I switch to stereo. Strong signal and music in mono but all quiet instereo with the meter dropping a couple of lights? Any ideas...thanks
Could have something to do with the muting circuit. Can you turn the muting on and off?
Also try to get a stronger signal. There's an internal muting level adjustment, VR130.
Technics SA-202 AM/FM Stereo Receiver Manual | HiFi Engine
Also try to get a stronger signal. There's an internal muting level adjustment, VR130.
Technics SA-202 AM/FM Stereo Receiver Manual | HiFi Engine
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That means the tuner is muted in stereo, due to higher than set threshold noise level.
Try a stronger station, or move the antenna for a stronger signal. If it does this on
all stations you could try changing the threshold level with the internal control VR130.
Try a stronger station, or move the antenna for a stronger signal. If it does this on
all stations you could try changing the threshold level with the internal control VR130.
According to the SA-202 service manual.........the toggle switch, 2nd control from the right on the front panel, switches the muting on for auto/stereo or off for mono.
Be sure to get the right pot. Changing one of the other pots next to it could cause problems.
But you still might need more signal strength to get stereo with full quieting on most stations.
That could mean a better antenna, or a better location for it (usually higher up), or aiming it
differently, even if it is just rabbit ears or a twin lead dipole. If the station transmitter is too far away,
say 25-30 miles, you may have to use mono reception regardless, due to the 20dB higher noise
level in stereo than in mono, in the best of circumstances.
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It is not uncommon for FM discriminator alignment to drift slightly over the years, making the unit think that it is not tuned properly and hence engage muting. Retweaking the center frequency usually is not too hard, but you really want service docs for the unit (schematic + alignment procedure) and some clip probes for the moldymeter.
Looks like HFE has a SM. T103 is your man, which is the only discriminator adjustment in this unit. You're supposed to minimize DC voltage measured between TP103 and TP104, with a 100 µH inductor in series with each lead to keep the RF in (or out?). If you don't have any small inductors, I imagine a couple of 10k resistors or something would work as well... they tend to remain quite resistive into the VHF range, should do for a 10.7 MHz IF. Even those should not strictly be necessary, but watch out where you place your probe leads I guess.
Looks like HFE has a SM. T103 is your man, which is the only discriminator adjustment in this unit. You're supposed to minimize DC voltage measured between TP103 and TP104, with a 100 µH inductor in series with each lead to keep the RF in (or out?). If you don't have any small inductors, I imagine a couple of 10k resistors or something would work as well... they tend to remain quite resistive into the VHF range, should do for a 10.7 MHz IF. Even those should not strictly be necessary, but watch out where you place your probe leads I guess.