Ok … thats something i dont know how to do yet …
ok …
When thats done … does GQRX use those values for Rx and Tx … i need to better calibrate in the 3.8Ghz area …
@Kc7noa Yes I’m sure GQRX will use all the appropriate calibration algorithms or calibration caches automatically … But GQRX has no transmit function 
I suppose you could try different Rx calibration settings by caching them in limesuite? I don’t think limesuite and GQRX will run at the same time though But you can alternate between them ok.
lol, yea… they dont … i tried some time ago …
Nice work and thanks for sharing!
Also, if we ever introduce a prize for best use of emoji you stand a good chance of winning 
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Damn the potatoes! Full steam ahead! Is there really $130e6 up for grabs??
Congrats!
Sometimes the best solutions can come while performing those menial tasks. Like planting potatoes.
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It is masterful isn’t it…
I’m not sure if this is the right thing to do as the next step in this project or not, but …
Anybody know how to build a power amp from scratch ie PCB level? I’m guessing it would need to be about 1 watt. I’m talking power here, not decibels. I can find components, but no instructions / schematics on how to use them. eg.http://www.mouser.com/ds/2/389/pd57002-e-955182.pdf
@martywittrock … did you build a power amp?
Search for cell phone PA chips, order some samples and use reference design from producer of chip.
That was my approach couple years ago. Target application was biological study for cell RF.
In the mean time your quick solution can be one from my friend Adam 9A4QV →
look for →
HackRF TX amplifier modification
This part is not necessary because Lime have no Bias-T option, so leave the board as is
and apply DC power on standard pads…
Regards
Dj
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Thanks @9a4db - I’ll check that out.
I’m currently looking at this chip as we speak: http://uk.rs-online.com/web/p/rf-amplifiers/7165154/
It’s 50 ohm matched and has a useful schematic in the datasheet.
What type of modulation should it handle?
Power is one aspect, linearity the other.
But it will be handling higher order modulation waveforms, e.g. 16QAM, with requirements quite different to modes like FM and SSB etc. I would have thought.
yes linearity is an important consideration and the device has to be designated as ‘suitable for LTE / cellular base station’.
Skyworks usually has some interesting amps.
Iirc they publish reference designs including Gerber files and BOM.
One can then get PCB as well as pick and place off site.
I’m mobile, otherwise I would provide links.
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LimeSDR now controlled by Arduino via SPI:
Many thanks to Zack!
PS. Sorry it took so long - JTAG adapter issues meant that I had to have a special adapter PCB manufactured - it arrived in today’s post.
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Amazing project and glad you shared it all too! Inspiring to follow the progress. And they wrote that you won money! I recall you had won from hackaday a while ago but did you win more?
Idea for your next project: TaterBot sort of like a Roomba for the potato field. Chases out varmints. Applies mulch and water as needed and picks them when ready. Where does LimeSDR come in? Telemetry of course. You’ll need at least two LimeSDRs. One for the PotatoBot and one back at the ranch. The ranch SDR will do double duty as a GPS rx/tx to give PotatoBot centimeter precision and accuracy. A homegrown differential GPS setup.
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