Re: [Discuss-gnuradio] RFX900 Failure

[Marcus D. Leech]

On 02/24/2010 12:42 PM, David Evans wrote:
> Hi all,
>
> Power output has significantly dropped, initially by 8dB, now much more.
>
> My first thoughts are that the PA has failed, so is it possible to
> break the transmitter...
> - by prolonged transmitting at high power (i.e. setting it to/near
> maximum)?
Probably not
> - using a mismatched antenna?
> - mismatching resulting in VSWR effects? (err, without a load)?
>
RF amplifiers don't like transmitting into badly-mismatched loads.  They
can definitely get damaged that
  way.  Anything below 2:1 VSWR will probably be OK, but beyond that,
you flirt with amplifier damage.

> I'm obviously going to have to test now, where to start, any
> suggestions, like what voltage swing before and after the 3315 should
> I expect?
>
> Many Thanks
> David
>
>
>
>
>
>
> _______________________________________________
> Discuss-gnuradio mailing list
> address@hidden
> http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>
>


-- 
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org