Peter -
>....... My experience with 723s (backed up by a fair
>number of engineers who've had similar problems) is that they are very
>prone to RF pickup.
This is a non-issue. The fix is 2, 100k, 1/4w resistors at the 2 input
pins.
> The other aspect
>that makes me a bit dubious about using 723s for a new design is their
>age - they could very rapidly disappear - semiconductor companies have
>a habit of killing older products on older processes.
723s are still being manufactured, as are 3-500Zs, as are 811As. Buy
some spares. I'm guessing that the 723 used in the amplifier will
probably last longer than the amplifier. I am still using the original
723 in my 1000v regulated 8169 screen supply.
- Rich -
R. L. Measures, 805-386-3734, AG6K
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