You should check to see if your antenna settings are right and whether the RX1_L shunt is enabled. The L shunt was enabled the first time I used mine and killed all incoming signal.
Thanks @Kryan92. Where? Which tab? Iāve been using SDR-Console to control the Lime, but you never know ā¦ maybe Simon has overlooked this one?
I used LimeSuite GUI for my initial testing, and donāt have any experience with SDR Console. Under LimeSuite it should be under the RFE tab for the āinput shorting switchesā section. SDR-Console may or may not be properly untoggling them when you switch the antenna setting.
Also general reminder, max your gains at least (LNA + TIA + PGA)
Hi @W7BOT,
As far as I see it is OK. You are receiving a test signal correctly (step 4.6).
If you use example.ini file, then RX RF input selected is RX1_L.
Do you have a signal generator to test the RF input?
Hi @Zack,
Thanks for your time so far. Good to know the Lime is receiving a test signal correctly. Sadly, anything other than a test signal is where Iām having the problem. When it comes to using it as a true SDR (i.e. receiving REAL signals), itās performance is totally unacceptable:
I have been comparing Limeās RX performance to other equipment I have here:
- Icom IC-7100 HF/VHF/UHF base station transceiver
- Baufeng BF-F8HP VHF/UHF hand-held transceiver
- Icom IC-PCR1000 comms receiver (0 - 1,300mHz)
- cheap RTL-SDR stick
Different antennas tried:
- the standard 2.4G WiFi antennas that came with my order
- a 12 inch whip antenna I use on the handheld
- my main RX antenna - 30mHz-1300mHz discone up 40ft in the open
In every single case, the Lime is not able to receive the signals that my other equipment is easily receiving.
E.g very strong FM broadcast station on 106.500 - all other receivers RX the station S9+ even with the 12 inch whip located indoors on my desk. Lime doesnāt even show a tiny blip on the FTT screen (or on the SDR-Console waterfall). When connected to my 40ft-high discone, Lime is only barely getting the station, whereas all my other receivers are just about overloading and I need to use the attenuator to prevent them catching fire.
Same for 144/430mHz ham bands. Same with 156mHz marine frequencies. Same with strong NOAA weather station on 162mHz. etc, etc, etc. Iām not even going to try <100mHz because we all know Lime is real deaf in HF spectrum without the end-user mod (which Iām not willing to do just yet ā¦ would void the warranty).
Itās not even able to see my WiFi router signal on channel 1 (2,412mHz) with itās little Wifi antennas attached.
There is NO combination of gain settings and/or antennas and/or RX1_L, _H, _W ports that allows the Lime to receive an acceptable signal.
Basically, as it is right now, this $300 brick is getting itās ass kicked by even my cheap $25 RLT-SDR dongle. Thatās not what I was expecting when I backed this project.
As for signal generator, yes, I have one, but not specifically designed for RF. Mine does 0-200kHz only, 0-2V P-P, ouput impedance 600 ohms. Iām guessing this will not be good enough to ātest the RF inputā as youāre suggesting.
But it seems to me Lime makes a good signal generator itself. Why donāt I loopback one of the transmitters into the RX stage with a uFL cable?? All Iād need is an āexample.iniā that sets up LimeSuite to do that. Could you provide such a āexample.iniā file for me? Or maybe a Pothos script? Iām not yet familiar with GNURadio or Pothos ā¦ not enough to write my own script anyway (Iāve only had Lime 4 days).
And I want to get to the bottom of this quickly, so that we can start the swap-out process as soon as possible. Iāve already waited nearly 9 month to get this far ā¦
73s de Dave W7BOT
Dave,
can you please do me a small favor.
Put your Lime somewhere within FM broadcasting band with at last 15 MHz bandwith
than select RX1 L or RX1 W inputs but, leave that input open.
Use small tip with un-shielded cable from your measuring sets (AVO meter or similar)
With magnifier glass try to contact only center tip of selected RX input.
Let us know if any change noticed in signal level over all bandwith, screen copy can be
nice tooā¦
73
Djani
Hi Djani @9a4db,
Good test. Iām guessing this is what you mean, right? ~50cm unshielded wire connected on RX_L.
1st screenshot - no ant
2nd screenshot - wire ant
73s
Hi Dave,
I think Djaniās point was connecting antenna directly to U.Fl connectors on the board. Today is ETA for LimeSDR, will clip off coils and do A/B tests.
73,
Yuri N3QQ
@nsiradio, @9a4db Hi guys. Got it. Tried that too, and not much difference. Only the noise spikes have moved in the spectrum a little.
1st - no ant
2nd - wire ant
By the way, looking closely, I see my board is missing a few components (just below T4 and T9). See 3rd. Can someone confirm those are supposed to be no-pop?
73s
Ok, thank youā¦ at last we know now that you have some inputā¦ so problem
is somewhere in chips either hardware or software setup.
Your board is ok, that places must be empty.
73
Djani
No, THANK YOU !!!
At least we also have confirmed the uFL to SMA pigtail is OK 
BTW Just please compare with my Lime ->
50 ohm terminated input RX1 W (modified) pigtail is uFL to N female, Al box RF sealed
1/4 lambda vertical input RX1 W (modified)
Djani @9a4db, wow ā¦ thatās quite a difference. Your waterfall is good and clean with no ant, then well-defined and strong FM stns with the 1/4 wave.
As you see, mine above are nowhere near as good. My āno antā (screenshot 1 - both cases above) is scattered with noise right up to -70dBm in some cases.
Now, I canāt compare apples-to-apples with your setup because:
- I donāt have a 50 Ohm terminator with SMA connector that I can try.
- My Lime is not in Al box, not RF shielded.
- You have N-type connectors, I have SMA
But I certainly donāt get strong signals like you do in second screenshot above.
Yuri @nsiradio has kindly offered to loan me his Lime tonight. So Iāll be able to compare his brand-new one to mine. Letās see what that uncovers.
73s
Got mine today. Took coils from RX1_L and RX1_W off before mailman left.
Had trouble with drivers on 32 bit PC W10. Used 64 bit laptop W10, connected LimeSDR, installed driver first, verified no yellow triangle, then installed Console V3. 1/4 wave vertical for 2m on a kitchen table, FM band is operational.
After Dave will take it for a spin tomorrow will do A/B comparison with other SDRs later on HF.
73,
Yuri N3QQ
PS: I would move 4.1.1 section of Wiki USB windows drivers to where it belongs, section 2.2 BIG letters Step 1 Step 2 Step 3
Almost missed it.
Aarrgghh. Hate you all for having such fine signals 
Hi Andrew, FM broadcast stations on 21MHz. BPF for 40m in line with antenna. Coils clipped off. Both check-marks for low-pass filters (analog/digital) checked. USB2.
Thanks Yuri
Hi @W7BOT,
Do you have a possibility to connect TX RF output to RX RF input using a cable? I could prepare a settings file for loopback test for you.
Hi Zack @Zack, yes, I have ordered a SMA-to-SMA loopback cable. Also proper Alum enclosure. Arrives Thursday. Thanks for settings file when youāre ready.
Today at noon, Iām visiting Yuri @nsiradio to test my Lime there against his. Weāll report results here later today.
73s
@W7BOT Hi Dave,
Couple of thoughtsā¦
I wonder why you have not removes the chokes from RX1-L or RX1-W? Sorry if I missed this on the previous thread,
My second thought is may be put your lime in the box and mail it to one of the guys in the USA that have already got theirs up and working so that they can just slip it into their set up and tell you the board is good or not. I figure the $7 each way postage to one of them will pay for itself as it will give you a definitive answer as to whether your board is bad or not. Just a thought.
As I have commented on a few times my own Lime seems to be about as good as a TS2K on VHF RX. Not good but certainly usable. Until a suitable SSB (Digi) TX software becomes available I have been using the Lime as a Poormanās Flex on 2m. IC746pro TX LimeSDR RX. It is very usable and my gut feeling is that it beats my USA made TVTRs on RX but does not compete with my DL made TVTR or the FCD+ but again they both would be hard to beat.
Just my thoughtsā¦
Paul
you posted whilst I was typing 