Fellow time-nuts,
I got the oppertunity to measure a cesium with my TimePod, I hooked up
on the FS 730/1 and noticed a bump in the phase-noise. I by-passed it
and the bump was not there. Turns out that it had a 20 dB increased
phase-noise at 700 Hz. So, we tried the other FS 730/1 they had,
Switch mode power supply ?
FLL or PLL loop?
Bruce
Magnus Danielson wrote:
Fellow time-nuts,
I got the oppertunity to measure a cesium with my TimePod, I hooked up
on the FS 730/1 and noticed a bump in the phase-noise. I by-passed it
and the bump was not there. Turns out that it had a 20 dB
Bruce wrote:
Switch mode power supply ?
FLL or PLL loop?
It's a distribution amplifier, so one wouldn't expect it to have an
FLL or PLL loop -- and the manual does not mention one. However,
according to the manual it does have (in sequence) a low-Q LC input
filter, a rather aggressive
Hi Bruce,
Switcher, yes. But with a fair bit of filtering on it. See page 18 of
http://www.thinksrs.com/downloads/PDFs/Manuals/FS730m.pdf
Switcher to get +24 V, LC-filtering with two serial 1,28 kHz filters.
Then an LDO (LM1086CS-ADJ) to drop it to +22 V which is actually used.
700 Hz and 2
The switcher loop compensation may cause peaking of reference or other
noise in this region.
Amplifier supply bypass networks together with coupling capacitors can
cause such peaking.
Bruce
Magnus Danielson wrote:
Hi Bruce,
Switcher, yes. But with a fair bit of filtering on it. See page 18
Hi
The hump sounds a lot like power supply noise.
Bob
On Mar 22, 2013, at 7:43 PM, Bruce Griffiths bruce.griffi...@xtra.co.nz wrote:
The switcher loop compensation may cause peaking of reference or other noise
in this region.
Amplifier supply bypass networks together with coupling
