[time-nuts] SRS FS710 spurs at 50Hz and harmonics?

Esa Heikkinen tn1ajb at nic.fi
Thu Oct 1 04:04:20 EDT 2015


Anders Wallin kirjoitti:

> I seem to get very strong spurs at 50Hz and harmonics with an old
> second-hand SRS FS710:
> http://www.anderswallin.net/2015/09/srs-fs710-noise-measurement/
> feature or bug? Anyone looked at the powersupply and figured out what parts
> to change?

If you live in a country with 50 Hz mains network then this sounds like 
a dead capacitor in the power supply. Usually this means that it has old 
fashioned linear power supply (with classic iron transformer). In that 
case, replace the secondary capacitors after the rectifier bridge(s). 
Check voltages with oscilloscope if you wanna see which ones, but it 
might be good idea to replace them all (there should't be many of them).

Should be very easy to fix.

-- 
73s!
Esa
OH4KJU


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