According to their manuals, the MFJ and JPS cancellers use the
unwanted noise signal from the main transmitting antenna. They nuke it
with an out-of-phase noise signal, from an auxiliary noise antenna.
BUT in each case, the canceller's output is ALSO its input, on
transmit.
If you never transmit, there is no problem, of course, but most of us
do transmit. Hence the relay problem.
If I had room for completely separate, widely spaced transmit and
receive antennas, I'd not have neighbours, (and I would be able to
afford not to have power line noise either). I'm sure that if it was
so easy to completely avoid switching the canceller out of line then
they would already have done it.
Some modern Q signals --- ??
QRM means there is a station on my frequency
QRMM means there are two stations on my frequency
QRN means its noisy
QRNN means its very noisy indeed
QRNNN means I can't hear a thing because of the noise
5NN QRNNN means I can't really hear you because its too noisy, but
I do need your QSL card.
73 John G3JAG
On 02-May-99 Roy Koeppe wrote:
>
> Mike et al,
>
> Yes, you said the magic:
>
> "It should not be too much of a major job to access the Rx side of
> the
> rig's tx/rx changeover and insert the QRM/QRNN phasing unit at that
> spot
> in the circuit, just a thought !!"
>
> This is the prescription for silent, QSK, QRO noise canceling. Just
> bring
> out a spare phono jack connected to your xceiver's "receive side"
> of its
> T/R relay. The canceler's output goes there, and the canceler's
> relays are
> not ever operated at all.
>
> TNX, 73, Roy K6XK
>
>
>
> --
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To: <tentec@contesting.com>
Date: 02-May-99
Time: 19:43:06
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