Re: [Discuss-gnuradio] software controlled antenna

[Angilberto Muniz Sb]

Chuck, I'm pretty sure you are aware of it -- that's
the bases of some Phased-Array antennas -- I'm woking
on this subject albeit its not related to USRP but
your experiment could be the starting point for this
kind of venture...

Good job,

Angilberto.



--- Robert McGwier <address@hidden> wrote:

> Chuck that is sweet.  Nice work.
> 
> Bob
> N4HY
> 
> 
> 
> Chuck Swiger wrote:
> 
> > This weekend's project was pretty easy and useful.
> My indoor antenna 
> > is a loop
> > with pretty sharp Q which requires touching up,
> manually, even if 
> > receiver frequency
> > is changed only 50kHz. I have to get up, walk over
> to the loop and 
> > turn a 365pf variable
> > cap to 'peak' the signal.
> >
> > I just found out about MVAM109 varactors, which go
> from about 40 - 400 
> > pf with
> > 0-9vdc bias, so it was fairly easy to use the
> gnuradio/usrp aux DAC 
> > 'D', the sigma
> > delta, which is brought out on J17 on the basic RX
> board, and makes 
> > 0-3.3 vdc
> > with 12-bit precision, a 2N2222 transistor dc amp
> with a 12v supply to 
> > boost it
> > up to 0-9vdc. Put two MVAM109's back to back on
> the loop fed thru 100k 
> > resistors
> > (they're very high Z) and now I can adjust and
> peak the antenna with a 
> > slider on the gui ;))
> >
> > --Chuck
> >
> > http://partsandkits.com/MVAM109.pdf
> > src.write_aux_dac(0,3,value)      0<value<4095
> >
> >
> >
> > _______________________________________________
> > Discuss-gnuradio mailing list
> > address@hidden
> >
>
http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> >
> 
> 
> -- 
> AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR,
> Packrats
> Laziness is the number one inspiration for
> ingenuity.  Guilty as charged!
> 
> 
> 
> _______________________________________________
> Discuss-gnuradio mailing list
> address@hidden
>
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> 


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