UmTRX

umtrx@lists.osmocom.org

189 discussions

by Alexander Chemeris

Hi all, Here is an update about a preselector frontend board on which we're working right now. Attached is an updated schematics of the board and 3D view of the board itself and the proposed way of mounting it to the main board. The github repository still contain an older revision of the schematics - I will update it a bit later when I get full project files from Andrey Sviyazov. https://github.com/chemeris/umtrx-schematics/tree/master/umtrx-v2-rxsel We would appreciate all constructive comments about the board design - from both RF and mechanical points of view. -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

13 years

Question about the name UmTRX

by Robin Coxe

I've been meaning to ask this question for a while and am just now getting around to it-- does the Um in UmTRX mean something significant in Russian? -- Robin Coxe | Close-Haul Communications, Inc. | Boston, MA +1-617-470-8825

13 years

Um Definition = Re: Question about the name UmTRX

by Martin O'Shield

> > Robin, > > > Um is the name of the GSM interface between the Mobile handset and the GSM > Network. > > Sincerely, > > > Martin > > > On Wed, Aug 22, 2012 at 2:18 PM, Robin Coxe <coxe(a)close-haul.com> wrote: > >> I've been meaning to ask this question for a while and am just now >> getting around to it-- does the Um in UmTRX mean something significant in >> Russian? >> >> -- >> Robin Coxe | Close-Haul Communications, Inc. | Boston, MA >> +1-617-470-8825 >> > >

13 years

Re: UmTRX preselector

by Andrey Sviyazov

2012/8/8 Jean-Samuel Najnudel - BJT PARTNERS SARL <jsn(a)bjtpartners.com> > Hi Andrey, > > Thank you very much for your reply. > > I understand your point of view regarding the ADF4350. I agree with you, > the ADF4350 still have quite good performances. I also agree that easier > software support is also important. It would just be a great news if we > could pass the GSM spec, at least as micro BTS. > > Regarding the GSM 1800 version of the selectivity board, it will not be a > problem to change the mixer and the filters. However, are you sure we will > be able to get the correct matching if we only change the passives ? Are > you sure we would not need to modify the PCB traces to get a good matching > for a 1800 MHz version of the board ? What do you think ? > Most of cooper would be 50 Ohm, so only FR-4 losses a bit higher. Also RF cables losses and so on, therefore 1800 parameters will be a bit worse, but it typical. About components, I've checked again and found that RF SAW filter for 1800 UL require coil at input (added). Best regards, Andrey Sviyazov. > > Best regards. > > Jean-Samuel. > :-) > > > > On Tue, Aug 7, 2012 at 7:27 PM, Andrey Sviyazov <andreysviyaz(a)gmail.com>wrote: > >> Hi Jean-Samuel. >> >> 1/ A few weeks ago, we discussed together about phase noise issues to be >>> able to pass the GSM spec. You explained HMC830LP6GE has much better >>> performances than the ADF4350. I know the HMC830LP6GE is a bit more >>> expensive but, as discussed together before, I really believe this worth >>> the extra cost. This would allow us to pass the macro or at least micro BTS >>> specs without the need for designing another slectivity board. This would >>> save a lot of work. Moreover, we espcially need this preselectivity board >>> for a micro or even macro BTS. In this use case, I really believe price >>> difference (like 40 or 50 USD) will be very low, especially compared to all >>> other costs of a mid-long range micro/macro BTS installation. Unless you >>> really disagree, I would really suggest to use the best performance >>> components as we reasonably can. >>> >> >> First of all, Robin said that ADF4350 already supported by UHD therefore >> it could save time to implement it for UmTRX. >> 2nd, I think that parameters differences isn't really as significant (few >> dB) as price and soft changing time cost. >> 3rd, it isn't last design and I am sure that we will change it for more >> functions, performances and for housing adaptations. >> Also I'm planing to buy HP4352 to design and measure PLL's, so of course >> I'll test HMC830 too, but now we just have to be sure that it will work >> properly and without risks. >> >> >>> 2/ In my deployment in Mayotte, I will also deploy GSM 1800 band base >>> stations because most of the spectrum I have is in this frequency band. To >>> avoid making another PCB for GSM 1800, could you design the board to allow >>> to populate either GSM 900 or GSM 1800 filters and matching passives with >>> the same PCB copper ? A single PCB would be easier to test and to maintain. >>> Moreover, this would save some costs as we will be able to order lager PCB >>> volumes. This could make a quite significant saving. Please let me know >>> what you think about this. >>> >> As I mentioned before, there are band specific components with same >> footprint. >> So, there are no changes required in PCB design for 1800 band, only BOM. >> For example, HMC485 instead of HMC483 and FAR-F6KA-1G7475 instead of >> FAR-F5KA-897. >> >> Best regards, >> Andrey Sviyazov. >> >> >> >>> >>> Anyway, thank you very much for this design. With UmTRX, this would >>> really make a cost effective and great performances base station. Thanks a >>> lot. >>> >>> By the way, as I am abroad, I may take a bit more time than usual to >>> reply to your e-mails. I really appologize for this and I will do my best >>> to reply as soon as I can. >>> >>> Best regards. >>> >>> Jean-Samuel. >>> :-) >>> >>> >>> >>> On Mon, Aug 6, 2012 at 5:07 PM, Andrey Sviyazov <andreysviyaz(a)gmail.com>wrote: >>> >>>> I've found first error: >>>> Missed AC block required for Vref pin of ADF4350. >>>> Also translated some components descriptions to English to avoid >>>> misunderstanding of Russian. >>>> All newest files here in zip. >>>> >>>> Best regards, >>>> Andrey Sviyazov. >>>> >>>> >>>> >>>> 2012/8/6 Andrey Sviyazov <andreysviyaz(a)gmail.com> >>>> >>>>> Sorry. >>>>> Zip file here :) >>>>> >>>>> Best regards, >>>>> Andrey Sviyazov. >>>>> >>>>> >>>>> >>>>> 2012/8/6 Andrey Sviyazov <andreysviyaz(a)gmail.com> >>>>> >>>>>> Hi all. >>>>>> >>>>>> Here first release of preselector project, schema and BOM. >>>>>> Any questions and suggestions welcomed. >>>>>> >>>>>> Best regards, >>>>>> Andrey Sviyazov. >>>>>> >>>>>> >>>>> >>>> >>> >> >

13 years, 1 month

UmTRX/OpenBTS at the GnuRadioConference and OpenHardwareSummit

by Alexander Chemeris

Hi all, I've just got an approval from Tom Rondeau that we'll present UmTRX at GRC at the hardware session (we'll be added to the official schedule soon): http://www.trondeau.com/grc2012-dates/ We'll be also doing a demo session at the Open Hardware Summit, showing OpenBTS with UmTRX: http://summit.oshwa.org/ Come visit us there! -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

13 years, 1 month

Fwd: [Discuss] OHS tickets are now available

by Alexander Chemeris

Thomas, Robin, Sylvain, If you want to attend OHS, I recommend you to get tickets NOW - they are ridiculously few of them left. ---------- Forwarded message ---------- From: Catarina Mota <catarina(a)openmaterials.org> Date: Sat, Aug 4, 2012 at 2:20 AM Subject: [Discuss] OHS tickets are now available To: The Open Source Hardware Association Discussion List <discuss(a)lists.oshwa.org> We have two types of tickets: • Starving Artist Pass: ($50) For artists, students, and non-profits • Summit Pass: ($75) Everybody else All passes include: breakfast, snacks, post-conference drinks, and an amazing gift bag from our sponsors. Please note that this year we will not be serving lunch at the conference, but we will be in the beautiful Chelsea area of Manhattan where there are many restaurants for you to choose from. Ticket types are not strictly enforced, so please exercise your judgment. Check out the speaker lineup: http://summit.oshwa.org/2012/07/23/2012-speaker-lineup Get your tickets: http://ohsummit.eventbrite.com More info about the summit: http://summit.oshwa.org/ Cheers, Catarina & Dustyn _______________________________________________ discuss mailing list discuss(a)lists.oshwa.org http://lists.oshwa.org/listinfo/discuss -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

13 years, 1 month

Pletronics OHM4

by Alexander Chemeris

Hi, I've received 10pcs of OHM4048052GG010020-26.0M today. Andrey Sviyazov - could you measure their performance and test UmTRX with them? -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

13 years, 1 month

UmTRX in action picture

by Alexander Chemeris

We need a picture of UmTRX in action for the Open Hardware Summit web-site. Andrey Sviyazov - could you bring your UmTRX (the one with an enclosure) to the hackerspace to make a picture of it with antennas? -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

13 years, 1 month

LMS TxLO noise

by Andrey Sviyazov

Sorry, that was meant to be sent to the mailing list :) Best regards, Andrey Sviyazov. ---------- Forwarded message ---------- From: Andrey Sviyazov <andreysviyaz(a)gmail.com> Date: 2012/7/18 Subject: LMS TxLO noise Hi Thomas. Here forwarded my last e-mail with noise plots when I stopped work around it at first time, please see below. Please try to play around Tx PLL charge pump current (register 0x16) for better RMS phase stability. I think we should reach 1 degree or below. Alexander gave me the second UmTRX board and after checking and fixing all known hardware issues<http://code.google.com/p/umtrx/issues/list?can=1&q=&colspec=ID+Type+Status+…>I've got roughly the same LO noise plot. Possible Robin had no time to fixing all of our issues, so check them all please. And also check please what type of TCXO installed on your board. Best regards, Andrey Sviyazov. ---------- Forwarded message ---------- From: Andrey Sviyazov <andreysviyaz(a)gmail.com> Date: 2012/4/13 Subject: Re: LMS TxLO noise Hi all. There is progress with LMS PLL :) Pictures are attached here. t was discovered that 80 kHz spurs come from Ethernet, or rather from the ET1011. I unknowingly put the choke between transistor of 1V regulator and analog power 1V. As a result, the regulator has become unstable and oscillated 80 kHz with amplitude of 200 mV, which climbed into the LMS PLL. To correct this problem L46 should be replaced by jumper on all alfa version PCB's. Also I just played with current in the PLL loop, shown on the picture for clarity. Proved to be the optimal current 1,9 mA (you should write 0x93 in the register of 0x16). But, I think, for the RxPLL will be better use of the current 2.4 mA, because the nearest noises more important for Rx (you should write 0x98 in the register 0x26). Best regards, Andrey Sviyazov.

13 years, 1 month

UmTRXv2 final project

by Andrey Sviyazov

Hi all! Here last version PCB of UmTRXv2. In the next e-mail I'll include project files and cheapest BOM for debug variant. I think it is final, because of nobody desire to say me any suggestions (except Robin). Best regards, Andrey Sviyazov.

13 years, 1 month

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