frequency calculation FP error? #synth #u3s


HF
 

Hello all...
I recalibrated my U3S (now clocked with a Taitien TCXO) using the frequency setting of 26,999,984.  My TXs nominally at 144,490,480, ...500, and ...520 were then decoded at ...492, ...518, and ...497 respectively at VE7UTS's RX and ...475, ...479, and ...500 at VE7BPB.  The gap between the nominally 500 and 520 TXs was correct at both receivers, but both receivers picked up the nominally 480 TX about 14 Hz higher than expected.  I tried power-cycling the U3S; no change.  But when I reduced the frequency setting by 1 Hz to ...983, the frequency spacing at both RXs were back to the expected ~20 Hz.  Would a floating point calculation error generate an discrepancy of this magnitude? 
Halden NR7V


HF
 

Typo:  Instead of "492, ...518, and ...497", I meant "492, ...497, and ...518".  Oops.  -HF