Ah thanks for the info. I am in North America. There are no power interruptions. I looked around the board more and see this clock crystal, dont see anything to adjust it... can I maybe replace this crystal with a better one?Your photo shows two variable inductors (not variable resistors) for aligning the radio.
A clock radio usually has a counter circuit driven from 50Hz or 60Hz of your electricity. In Europe and North America it is usually very accurate but other places are not accurate which might be your problem.
If your clock radio has a battery then it is used to keep the clock running when the electricity power fails. It might have a variable resistor to adjust it but usually a very accurate crystal in an oscillator circuit is used.
oh, you are saying its getting 60Hz from the grid? Is there anything I can add to the circuit inside the clock to "filter" it to make it more accurate? The thing is. I have another Sony clock, also Dream machine, but different model (a few years older) and that one runs perfectly wihtout ever drifting in the same house (so same grid).The speaker magnet does not affect the clock. Most clocks use the 60Hz to accurately run the clock, the crystal is used during a power failure. I think your 60Hz has a very small error.
The reason I thought maybe replacing oscillator would work if maybe there is variance in manufacturing? Presumably manufacturer used the cheapest one possible that may have higher tollerances?If you are in USA and the clock is not keeping time then something is wrong.
60Hz line frequency is adjusted daily to get the correct number of AC cycles each day.
Presumably the 60Hz time-base circuit is not working and it is running off the 32768Hz xtal oscillator.
One thing to try is to disable the xtal oscillator by putting a 0.1μF capacitor across the xtal. If the clock stops advancing then you know where the problem lies.
Go back and read my post #13, where I answered these questions. If you don’t understand the aswers, tell us what is confusing you instead if simply asking the same questions over and over again.The reason I thought maybe replacing oscillator would work if maybe there is variance in manufacturing? Presumably manufacturer used the cheapest one possible that may have higher tollerances?
If I determine that its running off the crystal, what are my options in fixing that? What are the chances it was designed to run off of the oscillator and not line frequency?
This is the clock "service manual" but it doesnt provide any info on anything - https://servicemanuals.us/sony/audio/icf-c414.html
In the manual it says to use on power specified on the back, not clear if its saying 60Hz or 110V. Or both.Maybe that "Dream Machine" was made for a country that does not regulate the 50Hz or 60Hz frequency of their electricity, then the crystal oscillator is used all the time..
How does the Dream Machine know if the electricity is 50Hz or 60Hz? It measures it?
Well, I understand the use of cap to slow down the crystal. My question was regarding fixing it so that it uses the grid 60Hz instead of crystal.Go back and read my post #13, where I answered these questions. If you don’t understand the aswers, tell us what is confusing you instead if simply asking the same questions over and over again.
|Thread starter||Similar threads||Forum||Replies||Date|
|B||Looking for service manual for a Sony STR-DH190||Datasheets, Manuals & Parts Identification||0|
|A||Determining Amplifier Input Power||General Electronics Chat||11|
|Troubleshooting Sony STR-DH750 RECIEVER||Technical Repair||5|
|Sony CMT-SPZ90DB Micro Hi-Fi system sound output problem||Technical Repair||3|
|SONY CRT KV-32XBR15 Black screen with Red Green and Blue Lines, Sound OK||Technical Repair||0|
by Jeff Child