Alan,
selective level meters usually operates with 60-70dB difference between the 
strongest and weakest signals, and I've never found any problems with them at 
work when this is bore in mind. But of course, it is not the situation for 
amateur radio operation, and of course they have no agc, and no pre-selector. 
Just wonder if you've seen any paper about dynamic range for such instruments?
The other problem is that the pitch for cw signals might be 1800Hz and some 
modification might be important because you uusually need a 700Hz tone for 
manual reception of cw signal. How to modify the D2006 is shown on my site, and 
some other modifcations has been discussed earlier on the reflector

73 Jan-Martin
LA8AK

-----Opprinnelig melding-----

From:  Alan Melia
Sent: 5. april 2005 15:49

Hi all I have been advised by a friend that he has the above to dispose of.
I do not want to be involved so if you are interested I suggest you contact
him directly. He does not want to be involved with the hastle of eBay again.
[email protected]

As far as I am aware the SPM-12 ( a 200Hz to 6MHz Selective Level Measuring
set ) has the synchroniser digital frequency display and the 25Hz filter
options fitted. The PS-12 ( a matching generator with -60 to +10dBm output )
will track the SPM frequency with the addition of just a BNC coax patch lead
between the units, and then acquires the staility of the SPM.....good enough
for 30sec QRSS all night long, though not quite as good as an oven derived
reference. When used as a receiver it should be remembered that the SPM has
no pre-selection so may be more prone to IMD than a modern purpose-built
receiver. Nevertheless they work very well. This unit does not have the
demodulater option fitted, but that can be overcome by using Alberto's
SDRadio software directly on the ID (10kHz) output.

I think he has an operating manual on CD and I have a manual, and circuit
diagrams fo my own units
Cheers de Alan G3NYK