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g0orx / pihpsdr

Raspberry Pi standalone code for HPSDR (Protocol 1 and Protocol 2)
GNU General Public License v2.0
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receiver pre-amp #123

Open human-blip opened 3 years ago

human-blip commented 3 years ago

Is it possible to make the receiver pre-amp switchable?

g0orx commented 3 years ago

The preamp can be switched on/off in the Menu->RX

ozy

human-blip commented 3 years ago

I'm not seeing the Preamp checkbox for either of my radios.

First screenshot is for ANAN100 running protocol 1.

Screenshot_20200727_140756

Second screenshot is for ANAN100D running protocol 2.

Screenshot_20200727_140032

g0orx commented 3 years ago

For some reason I though you were using an ATLAS based system. For a Hermes/Angelia card the preamp on/off is disabled and the attenuator is used instead. Setting the attenuator slider to -20dB is the equivalent to turning the preamp off.

human-blip commented 3 years ago

Applying attenuation makes an audible difference but does not change levels on the S-meter or the panadapter or waterfall.

dl1ycf commented 3 years ago

The receiver preamp is not switchable in all these radios except the first-generation boards. The hardware simply is not there. Therefore you do not get the choice in the menus, doesn't this make sense? -- 73, dl1ycf.

dl1ycf commented 3 years ago

BTW, using a preamp or an attenuator does not change the real signal out there in the air, so this SHOULD NOT change S-meter and panadapter readings. A -73 dBm signal from the antenna jack should display as -73 dBm no matter what you do with preamps and attenuators (some programming effort went into this!).