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briskly · 20th Oct 2011, 6:48 pm

Thanks Geof, I'll check this.

Meanwhile, I've managed to get the band selector switch working so at least I have a working set using the LM386! I wonder, Paula or anyone else if you could help again? I took your advice, fitting a 220 uF capacitor across the power supply and a 10 uF capacitor to the bypass (pin 7). Using a 10 uF capacitor at the volume control connected to the input of the LM386 removed the distortion and the set worked beautifully in a lash up. However, I had to lengthen all the leads so I could thread them through through the back. I then mounted the 10 uF capacitor on the LM386 board for the lead to the volume control, as there isn't room for this within the set. But I then found that a fair bit of distortion had appeared again. I have managed to remove some of this by fitting a 100k resistor between the 10 uF capacitor and the volume control but it is still present to some degree and gets worse if I increase the LM386 gain. I also get some funny squeaks if a hand goes anywhere near the LM386 board, which is a nuisance as I will have to mount it on the back of the set until I can make a proper repair.

Andrew

20th Oct 2011, 6:48 pm	#72
briskly Retired Dormant Member Join Date: Oct 2010 Location: Chelmsford, Essex, UK. Posts: 98	Re: Toshiba IC70 Thanks Geof, I'll check this. Meanwhile, I've managed to get the band selector switch working so at least I have a working set using the LM386! I wonder, Paula or anyone else if you could help again? I took your advice, fitting a 220 uF capacitor across the power supply and a 10 uF capacitor to the bypass (pin 7). Using a 10 uF capacitor at the volume control connected to the input of the LM386 removed the distortion and the set worked beautifully in a lash up. However, I had to lengthen all the leads so I could thread them through through the back. I then mounted the 10 uF capacitor on the LM386 board for the lead to the volume control, as there isn't room for this within the set. But I then found that a fair bit of distortion had appeared again. I have managed to remove some of this by fitting a 100k resistor between the 10 uF capacitor and the volume control but it is still present to some degree and gets worse if I increase the LM386 gain. I also get some funny squeaks if a hand goes anywhere near the LM386 board, which is a nuisance as I will have to mount it on the back of the set until I can make a proper repair. Andrew