"Pierre L" wrote in message .cable.rogers.com...
I really don't consider a very slight adjustment to the shortwave frequency
every once in a while to be a big deal. For example, listening to the BBC
last evening, on 5975, after an hour or so, the display showed 5974. That's
the kind of drifting we're talking about.

This is perhaps a difference due to frequency range or manufacturing
variation, but if that was the kind of drift I was seeing I would have
never brought it up. The last couple nights I've been listening to R.
Australia on 9580. I tune it so the signal is maxed and the display
reads 9580. A couple minutes later (and I really do mean a couple
minutes), the display reads 9578. This, I assume, is due to tension
in the tuning mechanism. I re-tune to 9580. Five minutes later it
reads 9579. I, again, attribute this to mechanical tension. I re-tune
to 9580. Five minutes later it's back to 9579. Re-tune to 9580. I
start reading while I'm listening and stop paying close attention to
the display. Maybe fifteen minutes later I'm hearing a fair amount of
static and it's clear the radio has drifted again. The display reads
9578. Re-tune to 9580. Fifteen minutes later it's at 9579 again. It
did seem to become more stable at this point.

-- Jay

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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KAM,

It has been observed that by Tuning Down (CCW) to the Frequency;
and Tuning One-Kilo-Hertz above the Frequency. This method will
have the least 'apparent' Drift due to the Mechanical Tuning
System of the Grundig S350 "Super Radio" Tecsun BCL-2000.

Grundig S350 "Super Radio" Tecsun BCL-2000 eGroup on YAHOO !
GS350= http://groups.yahoo.com/group/Grundig-S350/
The Grundig S350 is the everyday everyman's "Volks-DXing-Radio".
A basic low cost AM-FM-SW Radio with Good Sound for: the bedside,
kitchen or work shop; a sports radio at work and in the office;
or portable for On-the-Go Radio Enjoyment; much like the
GE Superadio I, GE Superadio II and GE Superadio III.


hth ~ RHF
..
..
= = = (kamalakar pasupuleti) wrote in message
= = = . com...

I am looking for a feedback on the performance of Tecsun BCL 2000
from someone who owns it and experimented it's SW ability .

Thanks ,
Kam
..

can someone tell me how it compares next to a panasonic rf-3100 ( sw and
mw )
"RHF" wrote in message
om...
KAM,

It has been observed that by Tuning Down (CCW) to the Frequency;
and Tuning One-Kilo-Hertz above the Frequency. This method will
have the least 'apparent' Drift due to the Mechanical Tuning
System of the Grundig S350 "Super Radio" Tecsun BCL-2000.

Grundig S350 "Super Radio" Tecsun BCL-2000 eGroup on YAHOO !
GS350= http://groups.yahoo.com/group/Grundig-S350/
The Grundig S350 is the everyday everyman's "Volks-DXing-Radio".
A basic low cost AM-FM-SW Radio with Good Sound for: the bedside,
kitchen or work shop; a sports radio at work and in the office;
or portable for On-the-Go Radio Enjoyment; much like the
GE Superadio I, GE Superadio II and GE Superadio III.


hth ~ RHF
.
.
= = = (kamalakar pasupuleti) wrote in message
= = = . com...

I am looking for a feedback on the performance of Tecsun BCL 2000
from someone who owns it and experimented it's SW ability .

Thanks ,
Kam
.

bill smith wrote:

can someone tell me how it compares next to a panasonic rf-3100 ( sw and
mw )

The RF-3100 is double conversion (no images) and the tuning is much more
stable, because of the semi-synthesized PLL. However you can't get parts
for a '3100'.


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