Hi Adrian,
Totally agree about the SDR hardware getting cheaper, a good case in point is
the limeSDR mini which has more than enough flexibility for any ham style
project.
https://www.crowdsupply.com/lime-micro/limesdr-mini#products-top
Couple that with a rock64 and you could have a great low cost repeater, only
downside to that approach is I doubt you'll get the power much below 10w of
which is more of a pain for solar sites than something which is a bit more low
level like the chipset below.
Another chipset that I've eyed as a cheap option for a handheld radio is the
SX1255, maybe some of you guys on here with more RF background could offer your
comments on that chipset. At like $7 for pretty much your entire RF transceiver
it may be a good option for 70cm.
http://www.semtech.com/images/datasheet/sx1255_datasheet.pdf
Regards,
Daniel VA7DRM
Sent from Daniel's iPhone
> On Nov 11, 2017, at 6:41 AM, Adrian Musceac <kanto...@gmail.com> wrote:
>
> Hi Ross,
>
> My initial GSM tests were done in the 70 cm band with low power (0.5
> W). I recorded them here: https://www.youtube.com/watch?v=LC3GH0vp-iQ
>
> After that, as suggested by some local amateurs who are also part of
> the regulations comittees here, I moved it in the 1.2 GHz band with
> increased power. The frequency split in both cases being 5 Mhz. As a
> client, I use a modified version of gr-gsm which supports transmission
> (through the USRP SDR hardware). Osmo-trx will also somewhat work but
> needs some patches to make it compatible as a GSM client. You can read
> more about this subject on the OsmocomBB mailing list.
>
> So yes, I am using a SDR frontend as a client. Some people have
> figured out how to hack some old mobile phones to allow scanning and
> camping out of band. Myself, I spent some time trying to
> reverse-engineer Qualcomm hardware but gave up as too expensive in
> man-hours.
> Other YO hams are running LTE on the 2.3 GHz band also using open
> source software and Chinese phones which have this LTE band. I'm not
> that interested in LTE though because it requires a lot of computing
> power and running a base station on a small Linux board is not
> possible.
>
> The way I see it, SDR hardware will continue to get smaller and
> cheaper, maybe even hit a price point of $50. Might as well get
> adjusted to that.
>
> 73,
> Adrian YO8RZZ
>
>> On 11/11/17, Ross Whenmouth <r...@topwire.co.nz> wrote:
>> Hi Adrian,
>>
>> I suspect that many of the people here use proprietary SDR hardware - if
>> code is linked with an appropriate HAL (hardware abstraction layer) eg
>> libosmosdr/GNUradio, then it is pretty easy to swap the USRP for a
>> BladeRF, or LimeSDR, or any other SDR with suitable capabilities which
>> is supported by the HAL...
>>
>> Have you been using SDR for user GSM stations as well? or mobile phones
>> with custom configuration/special SIM card/hacked firmware?
>> Operating on 33cm or on a different band? (23 or 13 cm?)
>> Using the "standard" 45 MHz duplex split, or something different? (the
>> 33cm amateur allocation here in New Zealand is not wide enough to
>> accommodate a 45 MHz split)
>>
>>
>> 73 de ZL2WRW
>> Ross Whenmouth
>>
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