Re: Console Signal meter reading


Allan Isaacs
 

Hi Michael

There may be a problem here?

It depends on how the output from your signal generator is measured. Some will regulate the input into the generators attenuator to say 0dBm then rely on the attenuator to define the output at its socket.

If you connect a high impedance load to the signal generator its output will equate to the level indicated by the attenuator setting but, if a 50 ohm load is connected directly, this reading at the output socket will not be valid.

My Marconi TF2008 is marked to show this anomaly.

You could test this hypothesis with a high impedance scope?

73 Allan G3PIY


From: main@SDR-Radio.groups.io [mailto:main@SDR-Radio.groups.io] On Behalf Of michel soldevila
Sent: 25 January 2022 16:39
To: main@SDR-Radio.groups.io
Subject: [SDR-Radio] Console Signal meter reading

 

Hi folks,
I performed a simple test with my RSP2 receiver and my Marconi 2022D RF generator:
The RF signal was fed to SMA antenna port A via a short 50 ohms coax cable.
The Console settings were as follow:
-RF gain = 0 
-AGC On
-Visual gain = 0
-Mode = CW
-Bandwidth = 200 Hz
I noticed a difference of 20 dB between the generator output level and the signal meter reading; this difference is almost constant from1 to 50 MHz, for signal levels between -100 dBm and -50 dBm. The difference is smaller at -40 dBm level (only 10 dB). The Console signal meter reading is above the generator output level.
My question:
Should I use the "Visual gain" setting to compensate for that diffrence?
 73, Michel (F1GOC)

 

Join main@SDR-Radio.groups.io to automatically receive all group messages.