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vfo stability of ATLAS-210 is far to be good compared to present
standard .There is a drift in frequency until the vfo reach its
thermal steady state and there is also an instability if the
power supply voltage changes .In the past where nobody was operating
digital mode this was not a problem but now it is a different story
.The frequency drift due to thermal change is almost negligible if you
start your ATLAS 30 minutes before really transmitting .The drift
in frequency du to poor voltage regulation of the VFO power supply can
be reduce by changing the voltage regulator circuit .One
description appeared in 1977 in Ham Radio Magazine .It was in fact a
modification for ATLAS 180 but it can be also adapted for ATLAS
210 .You will find below a scanned copy of the article . |
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