>Date: Mon, 03 Sep 2007 00:58:34 +0000
>To:
[hidden email]
>From: VR2BrettGraham <
[hidden email]>
>Subject: Re: [Elecraft] K3 NB
>
>K6DGW replied to N6RY's apparently somewhat-not-serious
>response:
>
>> > How about some simple countermeasures (for a future firmware release):
>> > Blank, then transmit an equal length pulse (on a clear frequency, of
>> > course), with optional automatic ID every N minutes.
>>
>>If it's anything like the Russian woodpecker, it likely transmits a
>>string of bits using a psuedo-random code in each "pulse', and the radar
>>RX can separate it's own echoes from fake ones.
>
>One suggestion we had from RAAF's 1RSU (VK air force's unit
>that runs their OTHR systems) early on was that the Hainan
>woodpecker might be a comms system.
>
>A constant pulse train on HF would be hard to use to convey
>any data with either amplitude or phase. And no one has yet to
>see anything but the pulses that make the woodpecker sound.
>
>The reason why we could force the Russian woodpecker to
>move back in the late 70s/early 80s was because they
>apparently could not differentiate between echoes from their
>pulses & anything else that looked like them.
>
>Since then, technology has come a long way & it is easy to
>imagine the computing horsepower & DSP now available
>would make most active countermeasures useless.
>
>And in practice, that seems to be the case.
>
>I get the impression here that OTHR isn't a problem in NA. You
>lot are very lucky then. In ITU Regions 1 & 3, it is a _big_
>problem.
>
>73, VR10BrettGraham/p.
Subscriber Info (Addr. Change, sub, unsub etc.):
Locked
