On Monday, 12 August 2024 17:54:33 EEST you wrote:
QradioLink and Adalm Pluto certainly does some tx on 70cm.
Hardly moves the signal meter on the rx ham gear, but things like the
QradioLink roger beep is clearly audible. In tx ssb I can hear my voice.
Depending on how close is your antenna, that may not be normal.
I am able to open a local FM repeater almost full quieting without even
using an external PA stage on the Pluto (2 dBm output in the 70 cm
band). I would double check the RF and audio gain settings if I were you.
Otherwise, measurement of the transmit power is really required, and for
the kinds of power these SDR devices can output, there are plenty of very
cheap digital power meters that can tell you the signal level with 0.1 dB
precision, with or without included attenuators.
Consider that these SDR devices are really just waveform generators,
there is a lot of RF engineering involved to get a functional amateur radio
station out of them. Signal characterization, filtering for spurious output,
band-pass filtering the RX input, matching the drive input to an external
PA to avoid over-driving, compression and distortion, and the list goes on.
Adrian
