[Elecraft] P3 base line changes with span with.

[Stephen Prior]

Ed,

If you read through page 17 of the manual, it explains why the noise floor
(base line) changes.  This is the same effect you notice when reducing the
IF bandwidth on the K3 - a narrow setting will produce a lower s meter
reading than a wider one.

The pertinent paragraph is:

"The noise level will generally be lower on the P3
display compared to the K3 S meter. The reason is
that the effective bandwidth of the P3 is generally
one display pixel, which is approximately span /
450. The smaller the bandwidth, the less noise. For
example, if the span is 45 kHz, the effective P3
bandwidth is 45,000 / 450 = 100 Hz. If the K3
bandwidth is 400 Hz, it will show a 6 dB (one S unit)
higher noise level than the P3."

There's nothing wrong with the P3, it's just the laws of physics!

73 Stephen G4SJP

On 7 November 2011 17:09, K7WIA <emoss98133 at msn.com> wrote:

> I just did a check with the XG3 at -73 dbm it is right on at 100 kc span,
> and
> it is also right on with in 1 or 2 dbm at 10 kc..   but it is just the base
> line that drops.... ?
>
> Ed K7WIA
>
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