Mal said:
I have today been testing a Siemens Pegelmesser D2155 as a LF receiver.
Freq range 200 hz - 620 khz. B/widths 20 hz and 3.1 khz. Mode lsb/usb.
This instrument makes a fb LF receiver for 73 and 136 khz, with the narrow
20 hz filter and superb sensitivity.
.... These selective pegelmessers outperform any other receiver that I
tried on LF, including the FT1000mp/ >FT847/IC746/IC706/TS850/TS50, the
performance of these receivers are acceptable and some are much >better than
others but sensitivity is generally poor on LF, and selectivity with the
normal 200 hz filter is too wide, >although those with DSP are better.
I have had a Siemens Pegelmesser D2155 for some time and find that they are
excellent for what they are designed for - making signal level measurements.
However, as a general LF receiver I wouldn't swap it for my TS850, which has
plenty of sensitivity, even on small loop antennas.
For QRSS operation the selectivity is determined by the software so it can
be used with any receiver bandwidth setting provided that there are no big
signals in the passband that may desensitise or crossmod the receiver.
I have used the D2155 for CW but it is very tedious to on 20Hz - all the
signals have the same note.
Although the D2155 has a digital frequency readout the oscillator is
analogue with a digital frequency counter, which means it does not have the
resolution or stability required for the narrowband stuff we using now. I
think this difficulty could be overcome with an external DDS oscillator.
I think the Siemens Pegelmesser D2155 would make a good receiver if the
3.1kHz filter could be converted to something like 300Hz. There is no AGC on
these units as this would defeat the purpose for which they are designed.
Regards,
Peter, G3LDO
e-mail <[email protected]>
Web <http://web.ukonline.co.uk/g3ldo>
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