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HackRF, an open source SDR platform

kickstarter.com

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Re: HackRF, an open source SDR platform

#31

Post by aray »

phaet0n wrote: post #28

For people interested in other SDR options, I believe these guys were YC funded: Per Vices, http://www.pervices.com/ Their hardware is significantly meatier, supporting frequencies from 100kHz to 4GHz with a bandwith of 250MHz. The HackRF only has a bandwith of 20MHz, and bottoms out at 30MHz. I haven't heard much from them, or discussion about them, but they are out there.

It's also almost $900, and PCIe (not USB), and doesn't look very portable at all:

http://www.pervices.com/shop/index.php?route=product/product...

At that price point you might as well start looking at USRPs.

Re: HackRF, an open source SDR platform

#32

Post by aray »

oldgregg wrote: post #27

What would be the typical range for something like this or BladeRF?

I'd assume it depends heavily on your antenna configuration, line-of-sight, polarization, noise, etc.

Edit: I sent a question on kickstarter asking about TX power limitations so if mossman answers it, the answer will appear in the FAQ section.

Re: HackRF, an open source SDR platform

#33

Post by yyao »

gdc wrote: post #26

Yeah, the lack of < 30 Mhz means this would be a pass for me.

Depends on what you want to do. A lot of people think that they need more bandwidth or power to achieve something. This may not necessarily be the case.

QRP guys have crossed continents on less than a watt. I remember from my undergrad days that we've played with band passing the human voice. We managed to get surprisingly good results with 500Hz of bandwidth.

There's a lot of interesting things you can do with more power and more bandwidth. To echo a lot of the other comments made already, if you are doing this without much thought, this is generally frowned upon.

Re: HackRF, an open source SDR platform

#34

Post by benjamincburns »

cottonseed wrote: post #30

This is great. I met briefly with a company developing software radio products that led me to believe such devices are illegal or require special licensing. Is my impression wrong or has this changed recently? Second, can this do GSM, receive at least? Frequency band works, but maybe it doesn't have the bandwidth?

It's been a while since I've looked into this, but last I knew it was legal to listen to any band you want, but illegal to transmit on any band for which you don't posses the required license, if any.

Then there's all kinds of rules about transmit power. For instance, last I knew you could transmit unlicensed on the public FM and AM radio bands so long as you're under some minimal threshold - I think it was 1W.

Re: HackRF, an open source SDR platform

#35

Post by benjamincburns »

SubZero wrote: post #5

Would this be able to say...oh, idk...spoof and overpower digital TV channels in a localized area? I need to know...for science.

If you're having difficulty assessing the feasibility of something like this, you're going to have all kinds of trouble actually implementing your "diabolical" scheme.

Re: HackRF, an open source SDR platform

#36

Post by benjamincburns »

xradionut wrote: post #24
SubZero wrote: post #5

Would this be able to say...oh, idk...spoof and overpower digital TV channels in a localized area? I need to know...for science.

No. And you don't need to be an jerk and interfere with broadcasts. It's an antisocial activity frowned on by 99.99 percent of the public and hardware hackers. There's plenty of good science that can be done in all aspects of RF experimentation for a small investment of time and little money.

To give the GP the benefit of the doubt, there are plenty of low-power FM transmitter dongles that people use legitimately to play audio over low-cost FM radios.

Re: HackRF, an open source SDR platform

#37

Post by yyao »

cottonseed wrote: post #30

This is great. I met briefly with a company developing software radio products that led me to believe such devices are illegal or require special licensing. Is my impression wrong or has this changed recently? Second, can this do GSM, receive at least? Frequency band works, but maybe it doesn't have the bandwidth?

The question of receiving signals is more a philosophical one of ethics. The question of broadcasting signals is one governed by law. In North America, you can't broadcast on a part of the spectrum that you don't have a licence for. Wifi devices, 900MHz phones and CB radios and such operate in a frequency band which has special provisions for such use.

I looked at their product specification and there isn't any mention of phase noise of the local oscillator. It turns out that a critical requirement for tuning into GSM signals is the phase noise or jitter of the local oscillator. Chances are, they are using a pretty good cystal, but probably not good enough for a GSM base station.

There is a good reason why GSM base stations all run off rubidium standards. In fact, you can grab 10MHz rubidium standards for a very (relatively) cheap price off eBay. They are all from decommissioned cell towers.

There is a possibility that you can still tune into a GSM signal with a substandard local oscillator. However, this behaviour would be intermittent.

Re: HackRF, an open source SDR platform

#38

Post by yyao »

aray wrote: post #31
phaet0n wrote: post #28

For people interested in other SDR options, I believe these guys were YC funded: Per Vices, http://www.pervices.com/ Their hardware is significantly meatier, supporting frequencies from 100kHz to 4GHz with a bandwith of 250MHz. The HackRF only has a bandwith of 20MHz, and bottoms out at 30MHz. I haven't heard much from them, or discussion about them, but they are out there.

It's also almost $900, and PCIe (not USB), and doesn't look very portable at all: http://www.pervices.com/shop/index.php?route=product/product... At that price point you might as well start looking at USRPs.

They are very different.

If you are looking for something that you can run from a USB cable, this could be the perfect tool. Someone called this the Bus Pirate of RF and I think its a great way to describe this tool.

The SDRs from Per Vices are geared towards low latency and high bandwidth. You can't squeeze 4x PCIe bandwidth into a USB cable. Neither can you get sub microsecond latencies. You can't get this over an ethernet connection either. This is the application where the Per Vices SDRs come out as clear winners.

Re: HackRF, an open source SDR platform

#39

Post by sparky »

yyao wrote: post #33
gdc wrote: post #26

Yeah, the lack of < 30 Mhz means this would be a pass for me.

Depends on what you want to do. A lot of people think that they need more bandwidth or power to achieve something. This may not necessarily be the case. QRP guys have crossed continents on less than a watt. I remember from my undergrad days that we've played with band passing the human voice. We managed to get surprisingly good results with 500Hz of bandwidth. There's a lot of interesting things you can do with more…

He wants lower carrier frequencies, not more receive bandwidth. For example, HF [1] is 3 to 30MHz, and cannot be received by HackRF without an upconverter, which adds another board and another $43 [2] to the equation.

Also, if you want to go all the way down to DC, the upconverter approach doesn't really work.

[1] http://en.wikipedia.org/wiki/High_frequency [2] http://www.nooelec.com/store/ham-it-up-v1-0-rf-upconverter-f...

Re: HackRF, an open source SDR platform

#40

Post by nanospider »

xradionut wrote: post #23
SigmundA wrote: post #22

Earlier quoted context omitted.

Yeah I am annoyed at the separation in SDR hardware most seem to be 0-30Mhz or 30Mhz and up. HackRf is even offering a Ham-it-up upconverter to go with, the same one you would use with a DVB-T dongle. This gets you into the lower range but uses a mechanical switch to engage. Would really like soft control of it and be more integrated into the design. I might even try to wire a relay in to a Ham-it-up along with a ras…

That's the nature of the RF business. Most folks are interested in one ( HF), or have money for equipment that handles both. Building good equipment that handles the full spectrum is challenging.

http://thinkrf.com/wsa5000/
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