Re: LF: RE: Re: Re: HE3OM

[HB9ASB <hb9asb@gmail.com>]

Hi Rik
We do have an attenuator, there is no overload of the receiver. The BW of the antenna is very narrow - a good sign! The problem is: we are a big crocodile.
73 de Toni

2011/1/30 Rik Strobbe <Rik.Strobbe@fys.kuleuven.be>

Hello Toni,

 

if you want to use a big antenna as RX antenna sufficient attenuation between antenna and RX is essential.

For the 125m tower it might be 40dB or more.

 

73, Rik  ON7YD - OR7T

 

---

Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.org] namens Anton Bärtschi [hb9asb@gmail.com]
Verzonden: zondag 30 januari 2011 20:32

Aan: rsgb_lf_group@blacksheep.org
Onderwerp: Re: LF: RE: Re: Re: HE3OM

An hour ago I've sent this report to the LF group, but it did not appear on the reflector:

Hello LF friends
and many thanks for your patience, we are still in a learning process and testing phase. Today we had several problems. A broken Transmitter and hot capacitors, bad reception on LF and a strange receiving situation on 80 and 40m. plus some visitors, asking silly questions and touching critical parts, hi. But so far nobody got burnt.

• The broken TX: At the beginning we had to use low power. Then we fixed a faulty relay and could run the TX at full power, as some of you certainly remarked.

• The hot capacitors: The mast stands isolated from ground, but one leg is connected to ground via a huge coil (Choke). The inductance of this coil is far too low for 137khz. So we put some capacitors in parallel to create a resonant circuit on 137kHz. The brown Mica capacitors we used, got very hot and the SWR deteriorated. Now we deployed a huge variable capacitor from the old MF transmitter.

• Bad reception on LF: We used the transmitting antenna, a 125m free standing tower, also for receiving. Location is low noise, but this is probably not the best solution. we will try to use a separate antenna for the RX and next time I will bring another receiver to the site (1h driving from my QTH), which should be better (Icom IC-756ProIII). I heard stations calling in the noise, but it was impossible to decode them, despite 50Hz BW.

• Strange receiving situation on 40&80. Strong stations on the band (contest), but the stations calling us, very, very weak. Now we improved the receiving antenna and moved it away from the tower. Next time, cross band should be easier.
  

We will come back soon and we will further improve the station. Especially the RX situation. We still have to learn a lot. HE3OM will be active until end of February. So everybody should get his chance.

73 de Toni

PS. See pictures!

2011/1/30 mal hamilton <g3kevmal@talktalk.net>

PA0A was one of the stations calling HE3OM and got no reply, not heard.. I
think Toni has a serious RX problem, unfortunately no feed back to indicate
what is going on.

de mal/g3kev

----- Original Message -----
From: "Rik Strobbe" <Rik.Strobbe@fys.kuleuven.be>
To: <rsgb_lf_group@blacksheep.org>

Sent: Sunday, January 30, 2011 6:43 PM
Subject: RE: LF: RE: Re: Re: HE3OM


Hello Stefan,

Mal was at least 10 to 15dB weaker than usual (daytime signal). Normally he
is "head and shoulders" above the other UK stations and even most PA's -
that are much closer - cannot compete, apart from PA0A.
PA0A was at his usual strength, so I assume my RX/antenna was OK.
I have no idea why G3KEV was rather weak today. Less power than usual or
other antenna ?
I observed HE3OM and his audience for about 30 minutes and coundn't notice
any QSB (what is typical for combined surface wave / skywave propagation),
so I assume all signals were surface wave.

73, Rik  ON7YD - OR7T

________________________________________
Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.org]
namens Stefan Schäfer [schaefer@iup.uni-heidelberg.de]
Verzonden: zondag 30 januari 2011 17:14
Aan: rsgb_lf_group@blacksheep.org
Onderwerp: Re: LF: RE: Re: Re: HE3OM

Hi Rik,

I'm wondering. I've always thought Mal has a strong signal. Seems to be
rather the usual power levels well below 1 W ERP. Anyway, at least he's
well visible on my grabber, sometimes 30 dB above noise in QRSS-3. I
seem to have a very sensitive grabber ;-)

73, Stefan/DK7FC

Am 30.01.2011 14:56, schrieb Rik Strobbe:
> Heard here :
> HE3OM : abt. 40dB above noise
> DF6NM :  abt. 15dB above noise
> G3KEV : abt. 5dB above noise
> PA0A : abt.20dB above noise
>
> 73, Rik  ON7YD - OR7T
> ________________________________________
> Van: owner-rsgb_lf_group@blacksheep.org
[owner-rsgb_lf_group@blacksheep.org] namens Fausto Coletti
[faustocoletti@alice.it]
> Verzonden: zondag 30 januari 2011 14:49
> Aan: rsgb_lf_group@blacksheep.org
> Onderwerp: LF: Re: Re: HE3OM
>
> Hear HE3OM 579 in qso with DF6NM 529
>
> Fausto IK4NMF
>