Re: [Discuss-gnuradio] AR5000 and downconversion

[Joshua Lackey]

A few weeks ago I posted a list of receivers which have a nice amount of
bandwidth.  The AR5000 is definitely one which has ~10MHz on the 10.7MHz
IF.

Heck, even the PCR1000 has ~8MHz of bandwidth after surgery.  (It
supplies 500kHz without modification.)  I'm going to post some
instructions to modify the PCR1000 to allow this, but, although usable,
I still have a few issues.

It is certainly possible to resolve the 10.7MHz IF with the 20Msps ADC
card but it will be annoying.  If you want to use a receiver without
some external down-mixing you're really going to want an ADC card that
has a faster sample rate.  Eric is working on a USB ADC which should be
able to do this.

Do you have an update on your ADC design Eric?  (I'm going to get at
least 3 of them when they're ready.  I'd even be willing to pre-pay if
you need development funds.)

Josh


Quoting John R. Ackermann   N8UR (address@hidden):
> Hi Alan --
> 
> I doubt you'll find many radios that support a 6-7MHz bandwidth around a 
> 10.7MHz IF.  That's way too great a percentage of the center frequency for 
> traditional radio design to work with.  I suspect the 10.7 IF in the AR5000 
> is not going to be able to handle more than NBFM, or at most WBFM (eg, 
> 200kHz or so) bandwidth without major surgery that would likely render the 
> radio useless for normal tasks.  A radio that supports TV bandwidths is 
> likely to have a much higher IF, anywhere from 45 to 70MHz or higher.
> 
> John

-- 
Joshua Lackey, PhD. -- address@hidden