SDR-14 vs SDR-IQ
mo at ccr.org
Sun Jan 17 17:02:42 CST 2010
according to the technical docs, they use the same DDC
and the same ADC.
i can believe that if the -IQ runs the samples through the
PIC, it can't peddle very fast.
sounds like a good reason to use a TI OMAP and make the
whole thing self-contained. the OMAP has *no* problem
peddling a lot faster than that. that's what it's
designed to do - all the baseband processing.
On 1/17/10 4:57 PM, wb4jfi wrote:
> Mike O'Dell wrote:
>> I'm trying to reconcile why the SDR-IQ is so much cheaper
>> than the SDR-14
>> the high-performance ADI parts in both of them are identical -
>> the A/D and the digital downconverter
>> the data delivered across the USB2.0 interface is essentially identical
>> the -IQ has *more* filters and switching
>> the -IQ has *more* computes and digital hardware
>> as a result it's hard to understand how the BOM cost of the -IQ
>> is really any less than the BOM cost of the -14
>> yet the selling price of the -IQ is *half* of the -14
>> true, the -14 looks to have a slightly spiffier case,
>> and it might have a more stable, less noisy clock part,
>> but that doesn't justify a $500 delta in the price
>> what am i missing in this picture??
> I don't think they are not nearly as similar as you think. If I
> remember, the SDR-14 uses a similar A/D (or maybe the same one), but
> then the similarity ends. The A/D samples are processed differently,
> using different DDC chips if I remember. The SDR-14 can deliver up to a
> complete 33MHz bandwidth to the computer, if your computer can drink
> that fast. The SDR-IQ can only deliver 192kHz, if I remember correctly.
> I have an SDR-IQ, but could not afford an SDR-14.
> Whether the cost difference is accurate, or some premium is being
> charged for the SDR-14 above the hardware differences is up to the
> observer. I can look at both diagrams and give you more details, as the
> above is from memory only.
"Of course it's hard!
If it was easy, we'd be buying it from somebody else!"
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