[UK-CONTEST] Pre Amps

[Rob Harrison]

Hi Ken,

It's amazing how many sources of interference appear on calling frequencies 
or busy channels. I've one that comes up on 144.3 almost spot on, luckily it 
drifts HF fairly rapidly. I suspect it's TV related, as it's mainly in the 
evenings, and I'm beaming towards the houses. There's a birdie on 144.370, 
which doesn't help WSJT.

Or were they there before and we didn't notice until we needed to use the 
frequency?

As for pre-amps, well I've had to back off the gain on the onboard pre-amp 
in the FT-847, or all weird and wonderful things start to appear. Maybe not 
a good example, but "real" world problem.

73

Bob G8HGN


----- Original Message ----- 
From: "Ken Eastty" <ken.g3lvp at btinternet.com>
To: <uk-contest at contesting.com>
Sent: Thursday, August 05, 2010 8:54 PM
Subject: Re: [UK-CONTEST] Pre Amps


>
> .
>>
>> I ALWAYS use mast head gasfet preamps on 6m 4m 2m 70cms and 23cms,
>
> I don't think that Mast head pre-amps are of much use unless you live in
> a very quiet RF environment (like Bryn?) particularly on 2m & below.
> Even here right on the outskirts of Cheltenham just connecting the
> antennas on 2 or 4m pushes the S meter up a couple of S points.
>
> I have a QRM source which has just appeared on 2m, this peaks at S9+10dB
> when I beam E. What frequency? 144.280 - 310! & again .335 - 355.
> Judging by the noise it makes I guess that it's a switched mode PSU
> probably being coupled to the O/H phone lines. I've also had QRM (now
> cured for the time being) which came up right on 70.200!
>
> You could almost believe that these things were deliberate which they're
> not but the coincidence is amazing.
>
>>
>> I think that any station that gives a report far far  lower than  the
>> received report must really think about improving the set up.
>
> Not necessarily, unfortunately there seems to be a growing trend for
> some stations to give S9 reports on VHF to everyone they work just as
> happens on HF. I still try to give realistic reports on VHF but know how
> upset some people get if you give them anything other than the
> completely pointless 59(9)reports on HF.
>
> 73...
>
> Ken
>
> G3LVP
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