Pierre L schrieb:

I'll bet that with many digitally-tuned radios,
there's drifting too, back and forth, only, because the display stays fixed
at the frequency you punched-in, you don't notice it.

Indeed, receivers with PLL synthesizers also drift. However, their
accuracy only depends on the reference crystal (that's why TCXOs exist),
which eliminates a lot of other sources of drift found in rigs with
analog frequency synthesis. As for an example of "digitals" drifting, my
ICF-SW7600G will drift a few 100 Hz if the temperature changes by a few
°C, it also needs some warmup until fine tuning no longer needs to be
adjusted for SSB. However, that's already an order of magnitude lower
than the drift by a few kHz to be observed with a number of analogs.
(Also, you'll never see the typically analog irreversible drift that
causes the frequency to wander by a few kHz up or down in the same
direction over a longer period of time. Look here for drifting
measurements on a Sony ICF-5900W:
http://www.noobowsystems.com/restorations/icf-5900w/icf-5900w-e.html)

A definite plus of analogs is synthesizer noise, or rather the lack
thereof. Unfortunately this isn't worth much if not backed by a good
receiver concept, as it's usually the case today. (On my ICF-7601, for
example, there's plenty of intermod on the more crowded bands, along
with some FM breakthrough in the low 31m band. And this on a dual
conversion receiver.)

Stephan
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Stephan Grossklass wrote:

Pierre L schrieb:

I'll bet that with many digitally-tuned radios,
there's drifting too, back and forth, only, because the display stays fixed
at the frequency you punched-in, you don't notice it.

Indeed, receivers with PLL synthesizers also drift. However, their
accuracy only depends on the reference crystal (that's why TCXOs exist),
which eliminates a lot of other sources of drift found in rigs with
analog frequency synthesis. As for an example of "digitals" drifting, my
ICF-SW7600G will drift a few 100 Hz if the temperature changes by a few
°C, it also needs some warmup until fine tuning no longer needs to be
adjusted for SSB.

Do you know what the first I.F. frequency is for the '7600'?


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