[CQ] Cheap SDRs?

[AF6MQ]

thanks Josh,
i think i came to about the same ballpark as you.

so, since i already have an icom pcr-1000,
i'm going to build, buy, or mod, a 10mhz->12khz IQ downconverter,
tap into the 1st IF, and play from there.

that will give me at least a SDR receive to play with.

i love my pcr-1000.  got it new back in '96.
can be found on ebay and eham.net and qrz occasionally,
for about the same $300 they went for originally.
IMHO, best $300 hf-1300mhz front end ever.

if that goes well, i'll try tapping my old ft-757 for rx,
and then for tx.  (or maybee not).

i'm also going to try and get an Si570 chip,
and any other DSS/clockgen chips i can find to play with.
i wonder what i can do with a fast mcu w/ pwm and a clock  
multiplier.....

i want to learn fpga before i go into the usrb route.

--gaspo.


On Nov 23, 2010, at 20:52:15, Josh Myer wrote:

> First off, thank you to everyone who replied, there was lots of
> useful/valuable input in here!
>
> I spent a lot of time poking around, trying to feel out the
> possibilities at the same time as exploring the options of what kinds
> of things I want to do.
>
> Here's the single most valuable link I found in the process:
>
> http://f4dan.free.fr/sdr_eng.html
>
> From there, you can do your own research, but here's what I found for
> myself: There isn't an SDR for under $1000 that isn't only useful for
> HF, and none for under $100 that are generally useful.  Basically,
> with any device you can get for under $150, you're getting into the
> "QRP of the SDR world," where everything is crappy, but part of the
> fun is rolling with the crap.
>
> The Soft66AD gaspo linked to is surprisingly great, but it only really
> goes to 70MHz (6m band and longer), and comes in a little over $100.
> (http://zao.jp/radio/soft66ad)
>
> The SoftRock looks good if you're keen on tapping into your radio, and
> is incredibly cheap.  I'm a little nervous about both of these.
>
> Related to what Dr J posted, here's someone using a bit-twiddled
> BrookTree BT8xx to dump raw signal, which is awesome:
> http://www.domenech.org/homebrew-sdr/receiver-1.htm  Amusingly, he's
> just recording signal with the monitor off, and decoding it offline
> (this probably made a lot more sense in the Spain of 2004, though I'd
> have thought GHz class machines were common by then).
>
> As usual, TAPR looks promising but mostly just makes me want to die (I
> spent a lot of time with their wonderful documentation for the
> wonderful AX.25 protocol when hacking together ArdPRS).  In
> particular: their SDR stuff sounds interesting, but most of it's out
> of stock, and, in any case, you have to buy a eurocard backplane and a
> half-dozen daughterboards to do anything.  Admittedly, this makes
> things nice and modular, but I think it comes out more expensive than
> a USRP+daughterboards (assuming you could actually, y'know, buy the
> TAPR kits).  If you want more info on the TAPR stuff, go to
> http://www.tapr.org/kits_atlas.html is the backplane, try to go
> through the list at the bottom in alphabetical order, lest you get
> irrationally angry at the TAPR guys and write a really long, annoyed
> sounding paragraph about them in an SDR roundup.
>
> Other than that, there's the USRP.  Ettus has a really solid product
> which is a little rough as a ham radio, but is great for doing
> research.  The only real "failing" is that it's OMFG expensive.  The
> lowest base unit is priced near at the low end of the mid-range units.
>  But then you have to spend another $75 to get a basic HF receiver,
> and another $100 to get up above 50MHz.  And then another $75 to
> transmit in HF, and ...  On the positive side, the USRP only has 4
> slots to fill with expensive expansion cards, so you can't go too
> crazy with it.
>
> The newer USRPs look really great, but they're even more expensive.
> I'm sure they're reasonably good deals for what they are, but,
> starting at $1700 for the latest unit, plus all of the same
> daughterboard pricing, it's serious change.
>
> For my purposes, it seems like the USRP is a fantastic unit, and I can
> probably get by with the lowest end one and a few expensive
> daughterboards.
>
> Thanks again to everyone for their great input, and I hope this
> round-up is helpful to anyone else looking to do SDR now or in the
> future!
> --
> /jbm
>
>
> On Sat, Nov 13, 2010 at 9:31 PM, Josh Myer <josh at joshisanerd.com>  
> wrote:
>> Does anyone have experience with a cheap-ish SDRs?
>>
>> In particular, I'm looking for something that will let me tune in to
>> ATSC or FM radio bands, and which has enough bandwidth to pass back
>> the signal.  For FM, this is pretty simple (~50kHz bandwidth, so need
>> ~100kHz samples, at 16b/S it's only 200kBps), but ATSC is a bit
>> trickier (6MHz bandwidth).
>>
>> GPS would also be of interest, but 1.5GHz seems like it's just asking
>> for trouble.
>>
>> Thanks!
>> --
>> Josh Myer 650.248.3796
>>  josh at joshisanerd.com
>>
>
>
>
> -- 
> Josh Myer 650.248.3796
>  josh at joshisanerd.com
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