[ADXA] The 30 Meter Band

[w5zn at w5zn.org]

Greetings ADXA Folks,

There was a brief thread yesterday about some unusual signals appearing 
on the 30 meter band (10 MHz). For the benefit of our new radio amateurs 
(and maybe a few old dogs) some general info is in order.

The 10 MHz allocation to the Amateur Radio Service was acquired at the 
World Radio Conference (WRC, now know as a "World Administrative Radio 
Conference" WARC) in 1979 along with the 17- and 12-meter bands.

The 30-meter band is different from the other HF bands as the Amateur 
Radio Service allocation is secondary, not primary. The primary 
allocation is to the Fixed Radio Service and as such radio amateurs must 
accept interference from, and not cause interference to, the primary 
user (Fixed). That is one of the reasons in the United States we are 
only allowed CW and digital modes on the band (as well as it being a 
very narrow 50 KHz allocation) and our power limit is 200 watts 
PEP......you do know there is a power limit on 30 meters, don't you??? 
:-))

So what the heck is the "Fixed" radio service? It is an allocation used 
by governments around the world by embassy's, government experiments 
(troposcatter) and other communication activities, and any 
point-to-point communications.

It is possible that what we have heard recently is some "legal" 
government communication on the band. Legal does NOT include intentional 
jamming to one government's use of the band from another country. We may 
be seeing a bit of that!!!

 From time to time we will hear some weird "non-amateur" signals on the 
band that are most likely legal in accordance with the Fixed service 
regulations.

73 Joel W5ZN
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