Re: [TOEC] IMD i SSB-sändare

[Peter Sundberg]

Jag kan inte tro att det är "splatter" som stör radioastronomer, snarare
lär det väl vara våra starka sändare som orsakar problem i deras breda
mottagare (20 MHz BW eller mer) eller så överstyrs deras preampar. Dom har
sällan filter på ingången i dessa utan preampen har gain från vhf till
uhf/shf och tämligen medioker IP3.

Jag ser själv hur min EME-mottagare på 432 störs av gamla NMT
mobiltelefoner en bra bit uppåt i frekvens, men det är ju inte splatter
utan preampen grejar det helt enkelt inte.

Nåväl, med allt detta sagt så skall vi naturligtvis inte dra slutsatsen att
folk inte splattrar, det var bara kopplingen till radioastronomer som lät
lite krystad.

73/Peter SM2CEW



At 15:46 2003-09-13 , you wrote:
>
>> Förr kunde man ju komma undan med att köra CW contests istället
>> men nu för tiden med riggar som har rysliga nyckelknäppar är
>> ju det lika olidligt, istället för splatter så har man knäppar
>> över hela bandet.
>> Var i hela friden är vi på väg?
>> 
>> /EKM
>
>
>Ja det kan man undra. 
>
>På World Radio Conference WRC2003 var frågan uppe till diskussion.
Tydligen trycker radioastronomerna på och vill ha tuffare krav och
regleringar även för radioamatörerna. Om vi splattrar för mycket får vi
dåligt rykte..?  Se nedan
>
>73
>Bengt SM7EQL
>
>
>
>5.3 Agenda Item 1.8 - Issues Related to Unwanted Emissions 
>There were two aspects of this agenda item of interest to the IARU.
>
>The first relates to spurious emissions, that is, signals produced by a
transmitter at some frequency outside the allocated band (often harmonics),
which may interfere with other receivers. There are international
regulations setting limits on such spurious emissions, and the levels for
amateur transmitters are clearly defined. We are interested in ensuring
that these limits are not tightened to the point where home constructed
amateur equipment could not meet them. The very sensitive receivers used by
radio astronomers and remote sensing satellites are susceptible to spurious
emissions, and users of those services are continually trying to update the
limits to provide additional protection. This topic was not a major issue
for us at this conference. 
>
>A second problem is concerned with what amateurs call "splatter". In other
words, a poorly designed or operated amateur transmitter can cause
interference to other amateurs using a nearby frequency.
>To date, there have been no international regulations governing the level
of such splatter, although the radio astronomers and passive sensor people
have been trying hard to see such regulations put into effect. 
>
>The threat to amateurs occurs when one of our bands is immediately
adjacent to a passive sensor band, and amateurs operating near the band
edge might cause problems. 
>With support from the Canadian delegation, we were able to ensure that
none of the amateur bands were mentioned in any new regulatory constraints
approved at the conference. There are however, two 2007 agenda items
related to ongoing studies of such band pairs, and these should be
monitored in the ITU-R
>
>Referens IARU WRC report http://www.iaru-r1.org/wrc-4.html
>
>
>
>
>_______________________________________________
>TOEC mailing list
>TOEC at contesting.com
>http://lists.contesting.com/mailman/listinfo/toec
>