Correction, the point at which the images go away is ~ 900 MHz. Below is a link to a video where I sweep from ~ 40 MHz up to 2.4 GHz. Note that the images are only present in the beginning. The X310 is cabled directly to my spec-an with no additional attenuation.
https://youtu.be/jqUlK4WWvoQ On Tue, Aug 16, 2022 at 6:33 PM Dave NotTelling <dmp250...@gmail.com> wrote: > Marcus, > > I figured out the flash issue! It was related to the power switch > issue. There are four screws that go into the top and bottom of the front > panel of the chassis. Two from the bottom, two from the top. One of the > screws in the bottom was either too long, or not supposed to be there. The > one closest to the power switch was actually pushing on the bottom of the > board. Removing that screw released pressure on the switch, freeing it up > to work normally. Once that was fixed, the device had no problem reading > its flash. Dunno what was happening, and why it didn't cause other issues, > but now the radio powers on with no issue and all interfaces come up after > a second or two :D > > The issue of the daughtercards is a little more troublesome. I > hooked one of them up to a spec-an and set it to TX a tone that I could > move around from GNU Radio. What I found was that below ~1.2 GHz I get > images of the tone all through the radio's bandwidth. Above 1.2 GHz and > things look as expected (just the one tone). I was also noticing that the > 90-100 MHz range (FM radio here in the US) was getting overlapped with what > appeared to be TV or cell signals. Those should in no way be in the 100 > MHz region where I am. Tuning the radio around showed that I was seeing > loads of signals from much higher frequencies aliasing in. So, for fun I > attached a 100 MHz low pass I got from an Analog Devices class, and that > knocked out the images I was seeing in the FM band. But, now moving down > to ~ 50 MHz I was seeing images of the FM radio band. My assumption here > is that the filters on the daughterboards are hosed. Perhaps somebody fed > in a really strong signal and destroyed them? Are there two sets of > filters on the WBX? One for below 1.2 GHz and one for above? That would > help explain why my TX tests work > 1.2 GHz. Would the 100 MHz low pass > filter test prove that the mainboard isn't the issue? My fear previously > was that the ADC's and/or DAC's were broken. Not sure if that's still a > possibility. If it is, can you suggest tests I could run using a spec-an > and attenuators/terminators? > > Thanks for the help! > > -Dave > > On Mon, Aug 15, 2022 at 10:53 AM Dave NotTelling <dmp250...@gmail.com> > wrote: > >> Marcus, >> >> Thanks for the link! I didn't have any terminators on hand over the >> weekend, but will try that today. Appreciate the suggestion! >> >> -Dave >> >> On Mon, Aug 15, 2022 at 10:51 AM Marcus D. Leech <patchvonbr...@gmail.com> >> wrote: >> >>> On 2022-08-15 10:47, Dave NotTelling wrote: >>> >>> Marcus, >>> >>> It was crazy cheap (~$650), and reflashing on power up isn't hard >>> :) It's a fun toy for learning about RFNoC and just FPGA fun in general. >>> Came with two 40 MHz WBX boards. Is there a part number for the flash? Is >>> it something that can be popped off with a hot air gun? I think it did >>> come up on its own once. Curious if it just needs to be reflowed. >>> >>> The schematics are here: >>> >>> https://files.ettus.com/schematics/x300/ >>> >>> >>> >>> It does seem to have a working EEPROM since I can change the IP >>> address. >>> >>> I also noticed that both WBX boards have nasty spur looking tones >>> for several hundred MHz in the lower range of the WBX. Is it possible that >>> there are issues on the motherboard that could cause those issues? I have >>> a proper power supply arriving today to replace the ATX computer supply I >>> have been testing with (12 Volt) >>> >>> Could very well be clock issues or other things in the standard >>> daughtercard interface that are unexpectedly noisy. >>> >>> Do they go away if you terminate the inputs? >>> >>> >>> >>> Thanks! >>> >>> -Dave >>> >>> On Mon, Aug 15, 2022 at 10:41 AM Marcus D. Leech < >>> patchvonbr...@gmail.com> wrote: >>> >>>> On 2022-08-15 10:34, Dave NotTelling wrote: >>>> > Apologies if this is a repost. I don't think my original message >>>> made >>>> > it to the list for some reason. >>>> > >>>> > I recently got my hands on a used x310. It seems to work well, but >>>> > for some reason will not boot on its own. Vivado hardware manager >>>> > shows the device as not being programmed, and the network interfaces >>>> > don't come up (no lights on the SFPs). If I reflash the device with >>>> > Vivado it will come up and work as expected. Is there a way to test >>>> > the flash chip to see if it's alive? Running uhd_image_loader seems >>>> > to work fine, but the device still will not come up automatically. >>>> > >>>> > Thanks! >>>> > >>>> > -Dave >>>> > >>>> > >>>> This does sound like a FLASH issue. I hope you didn't pay that much >>>> for >>>> it... >>>> >>>> >>>> _______________________________________________ >>>> USRP-users mailing list -- usrp-users@lists.ettus.com >>>> To unsubscribe send an email to usrp-users-le...@lists.ettus.com >>>> >>> >>>
_______________________________________________ USRP-users mailing list -- usrp-users@lists.ettus.com To unsubscribe send an email to usrp-users-le...@lists.ettus.com
