AA8 Astrometry: consistent dec error vs MPC ephemeris

[PDC Skies]

Hi
I've been practicing using AA8 to generate MPC reports of minor planets. When comparing my results to MPC online ephemeris (timed to the closest minute) my results consistently match their position in RA but I consistently get variance in DEC of up to +/- 1.4 arcsec. Keeping the OC tight (max of 0.20) does not seem to affect the DEC variance. Why am I consistently low variance in RA and high variance in DEC? Suggestions?

Var
RA Dec
Object Sec Sec
1474 Beira -0.1 0.0
1474 Beira 0.1 1.4
1474 Beira -0.1 1.0
1474 Beira -0.1 0.8
1474 Beira -0.1 0.5
779 Nina 0 -1.4
779 Nina 0 0.2
626 Notburga 0 -0.3
626 Notburga -0.1 -0.9
626 Notburga 0 0.0
1 Ceres 0 1.4
626 Notburga 0 -0.6

Thanks
Steve

[fabdev]

Hi, is this variance expressed in RA/DEC coordinates ?
If yes, then it's correct, since the RA error must be multiplied by 15 to match the DEC error in arcseconds.
Fabio.