[UK-CONTEST] 160M band plan

[Donald Field]

Noise on receive is a huge problem on the LF bands, especially farther south
(near the equator it can be horrendous). This isn't helped by the fact that
many people use verticals, which are particularly prone to picking up all
kinds of noise. My situation here is not untypical. This was a quiet QTH
when we moved here 20 years ago, but noise levels have increased
dramatically during that time. I have recently been trying a K9AY loop for
receive, which helps a lot. It's not surprising that many topband Dxers use
Beverages and the like, and they are the ones who'll pick your callout first
time. Those extra 6dB or whatever from using a linear can make a huge
difference on the LF bands, much more so than on HF and, I suspect,
dramatically more so than on VHF.

As far as band plands are concerned, band planning on 160 has always been a
nightmare because different parts of the world have different allocations.
The German SSB allocation around 1835, the fact that the EU band doesn't go
below 1810 nowadays (did you hear the Caribbean stations calling CQ Europe
below there - oops?). The situation isn't as bad as it used to be (Russian
stations weren't allowed below 1850 for a long time, as I recall), but still
bad enough. So any bandplan tends to be advisory only and, when there's a
contest on, and because the band is so narrow, it tends to be suspended for
the duration. Not ideal, but kind of inevitable. I recall us discussing this
years ago when I was on the RSGB HF Committee, and there really wasn't a
solution that would work Worldwide, or even Europe-wide.

Don G3XTT

----- Original Message ----- 
From: "Andy swiffin" <a.l.swiffin at dundee.ac.uk>
To: <uk-contest at contesting.com>
Sent: Tuesday, March 02, 2004 9:10 AM
Subject: Re: [UK-CONTEST] 160M band plan


>
> >Regarding the *alligators* (all mouth and no ears) a few live with
> very
> >high QRN levels and genuinely can't hear - and then there is the
> >discrepancy in stations' ERP on this band - the big sigs are using
> 90ft
> >verticals with large radial mats and linears. The guy with his
> >feeder-strapped G5RV will hear the big signal but will respond with a
> much
> >lower ERP. Hence the discrepancy. But of course there are some poor
> >operators, as on any band/contest.
>
> There may be something I'm not totally understanding thats peculiar to
> these LF bands (having just come from the oposite end of the spectrum
> :-)
>
> On UHF/VHF if I hear someone using 400W and we've both got aerials with
> 12dB gain over a dipole then if I call them with just 12W I'm only going
> to be 15dB weaker (i.e. 2.5 S points) with them than they are with me.
> My 12dB gain aerial works just the same on receive as on transmit.
>
> So, on LF, I'm hearing guys at s9 running say a KW and I call them with
> say 60W  I'm generating  12dB less and so should be S7 with them,  yes?
>  OR is there some kind of non-reciprocity down here so that an aerial is
> less efficient on transmit than on receive.  I know that radials are all
> important (and I don't have enough yet although I'm busy sowing a good
> crop of copper :-) but shouldn't the effect be the same on rx as on tx?
> And how about one way propogation - does that happen?
>
> soooo much to learn :-)
>
>
> Cheers
> Andy
> gm8oeg
>
>
>
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