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TopBand: Re: 160 M DX window

To: <topband@contesting.com>
Subject: TopBand: Re: 160 M DX window
From: W8JITom@aol.com (W8JITom@aol.com)
Date: Fri, 29 Nov 1996 11:15:52 -0500
I've also been active on 160 since the early 60's. But hang all this
emotional junk and personal opinion, let's look at this issue technically. We
can talk all we want about "technology" elimiminating the need for the
window, it's done just the OPPOSITE!  It's no secret that some locations have
many dB advantage over stations just a few hindred miles away due to path
differences, and that all of our operating habits vary.

It's not suprising we all have such widely varying positions. But our own
opinions don't change the facts. The major problem is we have no SSB/ CW
segments.

Of the sky wave propagation bands, 160 meters has perhaps the widest ratio of
DX to local signal strength. DX is attenuated much more by path loss than on
higher bands, and there is no "skip zone" and very few GOOD directional
antennas (both on TX and RX) to reduce the signal level of close-in stations.

Transmitters are less than perfect, the BEST modern SSB HF radios only have
IMD levels about -30 dB below a single tone, worse than that in ssome or most
radios these products extend out to very high mixing orders. While it is
technically possible to get a good receiver you can't run out and find a
transmitter that is "clean" by 1960's standards on SSB, and that is an
indisputable fact.

So when some Lid (and I do mean Lid) parks his 40 dB over 9 SSB signal on
1845 to ragchew, or some DXer on 1827 decides to flip over to SSB to make a
quick SSB DX contact, he raises the noise floor perhaps to S 5 or 6 for
stations 10-15 KHz up and down. The better the receiving station and the more
effort put into it, the more evident the garbage is.

'The real problem is we need a CW only area, because with the new politically
correct outlook on life we will never be able to educate or ask anyone for
consideration.

A DX window really isn't needed until SSB gets mixed into the same area of
the band.

73 Tom

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