[Fwd: TopBand: Spurs, etc]
Tue, 10 Dec 1996 16:17:17 Eastern Standard Time
This message regarding phase noise performance of various transceivers was
posted to the topband reflector <email@example.com> by KM1H <firstname.lastname@example.org>
and brought to my attention by AA4NU. This conversation began with a "thread"
about spurious responses on 160 meters with the Yaesu FT1000MP
73, Scott Robbins W4PA at Ten-Tec
>This has been a issue since the first synthesized TX hit the band.
>From all indicators "it aint getting better".
>Take a serious look at the TX waveform picture in QST....most all of our
>rigs have been pictured over the past 12 years or so....at least back to
>the TS930 era.
>Now, look at that picture of the transmitted composite phase noise.
>Next, look at those spikes on either side of the carrier. Yep, most
>Riceboxes have them and they are typicallly 1.5 to 5 KHz from the
>carrier. Some worse than others, some have multiple peaks. What you see
>is what you hear.
>Those spurs meet FCC specs and are over 50dB down, most decent rigs are
>-80dB or better. But now define 50 to 80dB down from someone who is
>40-60dB over S9 on your meter. Never mind that the meter lies
>anyway....you will still hear that spur loud and clear from any LOUD
>station and even from the not so loud guy given the wide range of
>possibilities (all legal). At this juncture I wont even get into bad
>phase noise rigs in general....some should be banned. Or reciprocal
>What to do? Besides everyone going back to the old Collins or Drake rigs
>or buying a TenTec OMNI 6...absolutely nothing. The disease is inherent
>in your Ricebox along with the desire to have at least 1000 bells and
>whistles that are not really needed. All that high tech garbage and
>general coverage adds not only crap to your TX signal but also degrades
>the RX side. Yeah, I know, its hard to degrade anything on 160M, but
>many of us have a life outside of the band! ( Im now QRV up to 3.3GHz)
>and synthesizer crud is a big issue.
>Ask yourself....why do so many of the serious 160M ops (serious defined
>as over 250 countries) use rigs or slaved receivers designed for very low
>phase noise, spurs. etc.
>Got to keep this short, time to gas the generator. Now 2 1/2 days
>without utility company AC
FAQ on WWW: http://www.contesting.com/tentecfaq.html
Administrative requests: tentec-REQUEST@contesting.com
Sponsored by: Akorn Access, Inc & KM9P