Error When Turning On Bias-T

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tim_rtd
Posts: 99
Joined: Fri Jun 30, 2017 11:34 am

Re: Error When Turning On Bias-T

Post by tim_rtd » Mon Nov 18, 2019 10:11 pm

I can't help with your issue but I will tell you that most rtl-sdr builds don't use biast anymore.
If you do a rtl_tcp -h .... you'll see that T bias is turned on with the -T arg now.
Also if you did use the rtl-sdr -blog build ....you can use rtl_eeprom to latch the tbias on constant between boots.... use the rtl_eeprom -h ....and see the syntax

sigol
Posts: 9
Joined: Thu Nov 14, 2019 9:45 pm

Re: Error When Turning On Bias-T

Post by sigol » Mon Nov 18, 2019 11:38 pm

Thanks for the info, will check it out tomorrow.

I searched for years for an LNA and only found boards that required external power (and no case).

Wanted to use the v3 dongle again, so lets see.

tim_rtd
Posts: 99
Joined: Fri Jun 30, 2017 11:34 am

Re: Error When Turning On Bias-T

Post by tim_rtd » Tue Nov 19, 2019 12:29 am

I bought a hand full of those cheap China lna's for $10. Short out the cap at the 3 o'clock position and remove the L1 inductor at the 12 o'clock position and it is now a tbias LNA

rtlsdrblog
Site Admin
Posts: 2421
Joined: Mon Nov 19, 2012 11:54 pm

Re: Error When Turning On Bias-T

Post by rtlsdrblog » Wed Nov 20, 2019 5:41 am

Do any other programs from the rtl-sdr-blog driver version work? I can't seem to replicate your error no matter what I try.

Osmocom have also added rtl_biast to their official version now, but unfortunately the windows builds don't seem to include it yet.

If no other programs in the rtl-sdr-blog version work, then it's definitely some .NET / Visual C++ runtime corruption somewhere...I can try to compile a version based on mingw and see if that works for you.

sigol
Posts: 9
Joined: Thu Nov 14, 2019 9:45 pm

Re: Error When Turning On Bias-T

Post by sigol » Thu Nov 21, 2019 9:39 pm

Used "rtl-tcp -T" (OSMOCON binary) and was able to receive NOAA and FM, so is working. Thanks tim_rtd, read about it and forgot. :D

Tested with a short USB cable to v3 dongle, then LNA, then antenna coaxial cable to antenna.

Now need to make it permanent.

I also didn't trust the 4.0 to 4.8 upgrade, but it won't let me install 4.0 (a 1903 thing?).

The .NET version app could have shown "4.0" in white, but it didn't.

All rtl-sdr-blog binaries give the same error.

Willing to try a different build, thanks!

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