At 03:20 AM 4/25/2007, Nate Duehr wrote:

Proof positive that a reasonable solution can probably be found.

The Amateur allocation in the UHF band is a Primary allocation of the US Military in the US, with the specific wording in the NTIA documentation stating the military is to "treat Amateurs as Primary".

Well, the military over here as well have certainly been more of a friend than a foe. Our biggest dangers these days are not from the military, but from unlicensed gadgets, which have been approved for use in the 433 - 434 MHz band. What made this a really nasty problem is that the authorities put few limits on the emission types, leading to cordless headphones, crane controllers (nasty potential for OHS implications here) and other high duty cycle devices on the band. Wlesr, this happens to be about 80-90% of the available repeater inputs. Because of the duty cycle, CTCSS is not a solution, all you end up is a bunch of "deaf" repeaters that takes a kW to open. Had the devices been limited to low duty cycle applications, CTCSS would have been enough to prevent the occasional "blip" from someone's wireless doorbell opening up the repeater.

Oh, and as for satellites, well some of the cheap junk could drift into the 435 MHz region. I already know of some cordless headphones that drift as high as 434.900, which is outside the allocated band for these devices. These get into a repeater which was moved outside the affected band to get away from the problem. Oh, and interference from these devices "does not exist", as far as the legislation goes. It's actually written into the LCD (confirmed, I have read the clause myself).

The flip side of this madness is it is nigh on impossible to find a wireless doorbell or weather station that will work reliable in my environment. They use SAW filters in their receivers, and these get severely desensed by ANY 70cm transmissions, even the repeater output, 5 MHz away. The older 304 MHz stuff is much better for my uses. :)

Some new inputs (with an odd 5.4 MHz split) have been opened up to try and alleviate the problem with the repeaters, but it's a hack to work around the mess the authorities have given us.

Give me the military anytime to share the band with, they play ball much nicer than the rabble and the profiteers that feed them. :)

73 de VK3JED http://vkradio.com