[NLRS] Question on emission type

[Dr.Gerald Johnson]

Pulse emissions include radar as typical. Short bursts of RF energy, often 
used for echolocation. Also pulse width modulation, and pulse position 
modulation modes have been used for analog communications. 

I don't recall when 1296 lost its pulse permission, I think 10 GHz pulse 
was removed about 1957. There wasn't any explanation why as I 
recall. With 1000 to 1250 used for aircraft surveillance and identification 
radar, letting us buzz might confuse the transponders or the radars I 
suppose. And with 9.5 and up used for other pulsed radars I suppose 
they wanted to protect their equipment from amateur interference. 
With them running megawatt peaks and us running a few watts CW or 
SSB theres not much chance of hurting their transmitters, but still there 
could be a problem confusing their receivers if our pulse 
characteristics were close to theres. Then at least in 1957 there were 
lots of WW2 and Korean era radars rattling around in surplus that 
might have been stretched to the hamband and reapplied as real 
radars. Maybe even good for detecting storms...

I do recall in the 60s where some 1296 equipment was demonstrated 
on the ham band in pulse mode. Was the APX-6 and reported in QST. 
That's why I don't recall when the band lost the pulse emission.

In both losses it would have require someone or some agency to have 
petitioned the FCC to remove the emissions from those bands. There's 
probably details on both actions some where in the Federal Register.

73, Jerry, K0CQ


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