Return to KLUBNL.PL main page

rsgb_lf_group
[Top] [All Lists]

Re: LF: 500 obs

To: [email protected]
Subject: Re: LF: 500 obs
From: John Pumford-Green GM4SLV <[email protected]>
Date: Tue, 28 Aug 2007 20:46:07 +0100
Authentication-results: mx.google.com; spf=neutral (google.com: 193.82.116.20 is neither permitted nor denied by best guess record for domain of [email protected]) smtp.mail=[email protected]
Delivered-to: [email protected]
In-reply-to: <000701c7e997$763d2280$48d0fc3e@g3kev>
Organization: The Gammy Bird
References: <000701c7e997$763d2280$48d0fc3e@g3kev>
Reply-to: [email protected]
Sender: [email protected]
On Tue, 28 Aug 2007 17:17:57 -0000
"hamilton mal" <[email protected]> wrote:

> John
> Our two QSO'S yesterday. Daytime 1800z good copy at 439 no qrn but
> some qsb, but around 2200z although your signals were 469 the
> qrn/noise also increased so signal over noise had not improved.
> The German signals on 505.1 are solid with me all the time day and
> night. To compete me need a lot more power and that is the only
> answer, otherwise its going to be hit and miss.
> QSO GM4SLV and G3KEV
> 73 De Mal/G3KEV

Mal. LF,


Thanks for the 2 QSOs yesterday Mal, and for the comparative reports. 

You are always a good signal, day and night - nice clear sea path down
the east coast. At night obviously stronger, but the last few weeks have
been a nightmare for QRN which reduces S/N ratios terribly.

I can also always hear/see at least one of the DI beacons during the
day, and often 2, as well as the Swedish BHZ at times, although not
recently.

I am firmly of the opinion that an increase in ERP is needed too. Not
to "compete" as such, but to lift signals far enough above the noise to
make QSOs at least possible. Many people have high local noise floors
during the day which prevents working the weak daytime signals from
longer distances  and everyone has the very high atmospheric
noise level at night, which is negating any increase in signal levels
brought on by night-time conditions.

I have a low noise level here during the day and can here some very weak
stuff - eg G3XIZ, G3DXZ, G3UNT and others during the day (900km or
more!) I call them whenever I hear them but have never had a reply -
due, I believe, to my 100mW ERP signal being too far below their local
noise.

Another 10dB might help enormously. 20dB increase would seem only fair -
10W ERP...not unreasonable?

I'm a QRP fan - so I understand that power is not the only answer, but
100mW?  5W ERP would still be QRP, but it would be 17dB up on what we
have now.

At present I feel we're being held below a certain threshold of S/N
ratio that prevents many important contacts/tests/experiments.

If some people are currently "bending" the ERP limits (perhaps
unwittingly?) it makes for an unlevel playing field which distorts the
overall picture of what's possible and what's not. Might even count
against an eventual increase in ERP. We need to show that 100mW isn't
enough, even though ocasional great QSOs can be done at that level.

Best regards, 

Hope to be QRV again tonight at 11pm BST - QRN building nicely in
anticipation!

John


 


<Prev in Thread] Current Thread [Next in Thread>