Re: [IRCA] WC Nov 5 snapshot - SDR shoot-out

[Aaron Kreider <aaron@xxxxxxxxxxxxxxxxxx>]

Drake R8s are pretty cheap these days.  I'm selling mine for $450 (plus 
shipping) on Ebay.  Original owner.  Refurbished by the Drake R8 
manufacturer several years ago, and rarely used since
http://www.ebay.com/itm/Drake-R8-Shortwave-Receiver-/291918828655

...

Selectivity: The good SDRs with 14-16 bit AD converters (Elad 2, 
Perseus, the most recent Winradios, QS1R) crush traditional (non-DSP) 
radios (even the $10k models) in terms of selectivity both in terms of 
the shape factor (I think we get close to 1.1?) and number of filters 
(unlimited). I'm not sure about ultimate rejection.  You can also get 
great selectivity with the cheap portable DSP radios (though they have 
other problems).

Stability - varies a lot.  I think if you want extreme stability you 
need an external reference.  Now where SDRs have the advantage is that 
you can apply a general offset to fix your accuracy.  You can use a time 
signal or other known stable signal to get your accuracy as high as 
possible.  So it's cheap accuracy.  I can measure carriers with accuracy 
of plus or minus 0.1 hz on the QS1R on MW (or plus or minus 0.2 hz if 
the station is coming from 2000+ miles) which is useful if you want to 
null or maximize a station in a pile of others.  I can also receive 
frequencies with 1 hz resolution (the Drake R8 was 10 hz accuracy).

Sensitivity: I think is a tie.  In both cases the radios have more than 
enough sensitivity when provided with a half-decent antenna (and in 
low-noise areas you want a good/long antenna anyways).

Software: A SDR can be dependent upon good software from the 
manufacturer.  The one advantage you have over non-SDRs is that there 
are some software like SDR Console V3 (which I think is the best) that 
handle most of the popular radios (though unfortunately not the QS1R, 
but I can use the HDSDR).  By contrast the Drake R8 manufacturers came 
out with a single update (on EPROM).  In general you can expect that 
your radio will improve over time due to new software, whereas with 
traditional radios it is less likely.  The custom QS1R software is very 
good - though they are unfortunately never going to improve their 
recording function due to the company having limited resources.  I also 
have an SDRPlay and their custom software is frankly extremely quirky 
and some of the worst User Interface design I've seen.  The Drake R8 
also suffers from a bad user interface which was only partially fixed by 
the second EPROM.

Dynamic Range: my QS1R seems to have about equal dynamic range with the 
Drake R8.  It might be better, as I never used the R8 with an amplified 
antenna nor living 1 mile from an AM station.

Frequency coverage: SDRs typically have wider coverage.  The QS1R goes 
from about 0 khz to 65 mhz and can be modded to receive up to 200 mhz or 
so (I haven't tried it).

Modes: SDRs excel at having more modes, including digital decoding. For 
instance, the QS1R (and others) can decode an entire band worth of CW 
simultaneously.

Notches: I think I can create ten customizable notches (set the 
frequency and width) as well as an automated notch.  That said, I 
normally only need one notch.

Noise reduction: I'm still hoping that SDRs will improve upon their 
noise reduction and blanking techniques.  I never use "Noise Reduction" 
and Noise Blanking is useful, but could be a lot better. I think there 
are ways to identify noise and cancel it out that haven't been tried.  
For instance, I think you should be able to cancel out lightning noise 
bursts or the noise from switching power supplies (maybe I'm a 
dreamer!).  In the future, I'm hopeful that software based antenna and 
receiver phasing will be more common.

Now I had a great time with my Drake R8, spending thousands of hours 
listening to radio stations - especially in the 1990s when the dials 
were full of radio stations, but now I've got limited space and am happy 
to go with an SDR.

Aaron

--
High resolution map of race and income --> JusticeMap.org

_______________________________________________
IRCA mailing list
IRCA@xxxxxxxxxxxxxxxx
http://montreal.kotalampi.com/mailman/listinfo/irca

Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers

For more information: http://www.ircaonline.org

To Post a message: irca@xxxxxxxxxxxxxxxx