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Re: LF: LF T/A

To: [email protected]
Subject: Re: LF: LF T/A
From: "Dave Pick" <[email protected]>
Date: Sat, 18 Jan 2003 17:00:28 -0000
References: <[email protected]_Drake>
Reply-to: [email protected]
Sender: <[email protected]>
Steve.

Yes it's excellent. laurie and I did try some T/A tests last night but were
diappointed by the results around 0000utc and went off. It looks from your
latest graph that we should have persevered! The sig/noise at 0600 looks
very good. You need to couple that s/n figure to a big bell in our bedrooms!

Cheers.
Dave Pick
G3YXM.
----- Original Message -----
From: "Steve Dove" <[email protected]>
To: <[email protected]>
Sent: Saturday, January 18, 2003 4:40 PM
Subject: Re: LF: LF T/A


Greetings, fellow static-heads,

Having just returned from a week long business trip to find that
w3eee.com was still working(!) I'm also gratified to see that it is
of use . . .   also amazed by the great propagation it captured
last night.

(1)  Daytime noises

As Peter queried and Alan correctly answered, the daytime
noises evident are switch-mode 'squirglies' and the odd electric
drill from construction down the road.  When I'm here (w3eee.com
is in my downstairs office) I'm able to 'police' the house for known
grotties that have otherwise not been fixed, 'retired' or 'broken'.
These are the ones that require 'social engineering' to keep under
control.  There is a bad one from an adjacent property (300' away)
about which nothing much can be done.

That said, it is fairly clear if the 'squirglies' are causing false
readings;
that is the purpose of the 'control' traces from adjacent frequencies.
And since the 'squirglies' really only affect measurements when no-one
in their right mind is going to be attempting transatlantic QSOs, for
the immediate purpose they really don't matter;  obviously for the
science aspect, they have to go.  This is going to involve a new
antenna, further away from houses  -  since we're still armpit deep
in snow, and the weather-man's favourite utterance of late is
"single digits!" (of degrees Fahrenheit) this isn't going to happen
any time soon . . .

Incidentally, the signal strength 'bloom' centered around 1400z
on today's graph is real, and not a 'squirgly'  -  note that the
noises are well below the DCF trace.

(2)  Data clipping

As Alan has noted,  some traces show suspicious signs of the
measuring system clipping, or 'topping out';  this can be seen at
about the -8dB level on the 'Scorcher!' trace, and at 0700z+ on
the present trace. The actual data figures behind these traces
still show signs of wiggle, so, I'm really not sure.  However, since
there is 'plenty of room' at the low-level end of the graph, at the
next reasonable opportunity (i.e. when the 'puter falls over next)
I might spend the time to recalibrate it down 10dB, as per Alan's
suggestion.

Don't worry.  I'll let you know if it happens, just so that people
won't assume the band's over for the season!

        Cheers,

                Steve












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