[time-nuts] SRS FS 730

Charles P. Steinmetz charles_steinmetz at lavabit.com
Fri Mar 22 23:17:33 UTC 2013


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 differential-pair limiter, and a high-Q 
filter (a 10.7 MHz IF transformer tuned down to 10 MHz).  The signal 
then goes through a 2.4x IC amplifier to seven output buffers, each 
comprising three emitter followers in series.  There is a low-pass 
filter (11.5 MHz) and a 20 MHz notch filter on each output.  [This 
all assumes that Magnus was using an Option 1, 10 MHz unit, which 
appears to be the case from his description of the circuit.]

Magnus -- I have a manual, but no schematics.  If you scan and post 
the schematics somewhere (e.g., Didier's site, 
<http://www.ko4bb.com/Manuals/01)_Upload_Instructions.php>), we will 
be in a better position to help.

Best regards,

Charles











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