Bias-t in dsd 2.228

[barca1899]

Hi all please could someone tell me how to enable the bias-t in 2.228 iv tryed the -T but didn’t work
Thanks

 

[slicerwizard]

You have to be using a version of rtlsdr.dll that supports bias tee control. Looks like its size is exactly 119296 bytes.

 

[barca1899]

im using the SDRDuo I think iv found it
-T<num> Enable/disable RSP2 bias tee (0-1) [-T0]

 

[Annunaki]

You can obtain the BiasT dll from here

RTLSDR V3 BiasT driver.

 

[barca1899]

So this would work on the sdrduo??

 

[slicerwizard]

Looks like every FL user should already have it. At least it was in a zip file that they should've extracted it from...


FMP24 2.56

Added support for DSDPlus.siteLoader file.

Added support for bias tee control to provide power to a preamp.
Tested with rtl-sdr.com v3 dongles. Requires updated rtlsdr.dll file.

Use -T1 on the FMP24 command line to enable the bias tee.

Press "t" in FMP24 to toggle the bias tee state.

rtlsdr.dll

Updated file that supports FMP24 bias tee control.
This file should be in the same folder as FMP24.exe

 

[Annunaki]

The release I linked to on github is more updated.

 

[TheButcher]

I just bought an LNA too.

With the +4.5 or +5V on, use a multimeter on the dongles input (DC Volts). You should see +5V or so there with it successfully enabled...

Thanks for the info / tip re. "rtlsdr.dll" Mr. slicerwizard

 

[TheButcher]

"You have to be using a version of rtlsdr.dll that supports bias tee control. Looks like its size is exactly 119296 bytes. "

I see that version (size dll file) is contained in the Bias T driver linked in post #4...

Gonna play with it. My v3 dongle o/p's +5v so that side of it works. With the correct .dll (I hope) my new LNA will work... Results soon...

 

[Annunaki]

Rename librtlsdr.dll to rtlsdr.dll though

 

[kd5dga]

I use the NESDR SMARTee's from NooElec where the bias tee is always on.

 

[slicerwizard]

"You have to be using a version of rtlsdr.dll that supports bias tee control. Looks like its size is exactly 119296 bytes. "

I see that version (size dll file) is contained in the Bias T driver linked in post #4...

I don't see that. I see a DLL that's 242,925 bytes? It's probably fine, but it's not 119,296 bytes.

 

[thewraith2008]

im using the SDRDuo I think iv found it
-T<num> Enable/disable RSP2 bias tee (0-1) [-T0]

Curious, So did the '-T' option work in FMPP for your SDRDuo?
The help from FMPP which you show only mentions the 'RSP2'. If it doesn't then this could be one of the limitations of the driver which maybe useful for others to know.

 

[barca1899]

Curious, So did the '-T' option work in FMPP for your SDRDuo?
The help from FMPP which you show only mentions the 'RSP2'. If it doesn't then this could be one of the limitations of the driver which maybe useful for others to know.

no I could'nt get mine to work, im using a Nooelec LaNA when I press the -T no LED lights up on the LaNA, this a shame

 

[thewraith2008]

no I could'nt get mine to work, im using a Nooelec LaNA when I press the -T no LED lights up on the LaNA, this a shame

FMPP does not seem to have a keyboard shortcut to enable/disable bias tee once it's enabled via command line (-T1).

Setting '-T1' on the command line for the RSP1A also has no effect. On console screen it says it's ON, but testing voltage on antenna out is still 0v.
This is no real surprise as the API Specification shows different methods for each SDRPlay model.

 

[slicerwizard]

Sounds like the developers don't have 1A's or Duo's to work with. Maybe you could collaborate with them. The worst they can say is no.

 

[thewraith2008]

Sounds like the developers don't have 1A's or Duo's to work with. Maybe you could collaborate with them. The worst they can say is no.

Maybe, I don't ever use the RSP1A with DSD+ myself and I don't have an LNA as I live inner city where signals are quite strong so bias tee is not needed.
I think the SDRPlay API Specification should be good enough for them to add bias tee for different models if they need too.