From: Rik Strobbe <Rik.Strobbe@fys.kuleuven.be>
To: "rsgb_lf_group@blacksheep.org" <rsgb_lf_group@blacksheep.org>
Date: Sun, 24 Jul 2011 20:51:44 +0200
Thread-Topic: LF: DL6NN on 137
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Minto,

I was active on 136kHz with a similar antenna (15m high, 25m long "lazy-L" =
antenna) and in addition the losses were very high (abt. 130-160 Ohm).
Despite that I managed to work distances up to 1600km in regular CW (best D=
X =3D OH1TN).
So don't dispair.

73, Rik  ON7YD - OR7T

________________________________________
Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.org=
] namens Minto Witteveen [minto.witteveen@gmail.com]
Verzonden: zondag 24 juli 2011 17:26
Aan: rsgb_lf_group@blacksheep.org
Onderwerp: Re: LF: DL6NN on 137

Hi Mal,
1 KW should be enough for a regular CW QSO I suppose.
But on the other hand: my antenna efficiency is very low. I did some
calculations with MMANA-GAL and the radiation resistance of my 30 mtr long
end-fed antenna is only 0.019 Ohm=85
And there is no simple way to improve (lengthen or make it higher).
Measurement with my AIM4170 Antenna Analyzer shows a total antenna system
impedance of 150 Ohms at 136 KHz. So the efficiency is only 0.019/150 =3D
127x10^-6.
This means that with 1 KW output the ERP is only 0.13 Watt. I hope it is
enough..

Kind regards,
Minto pa3bca




--------------------------------------------------------------------------
Ceterum censeo Carthaginem delendam esse
-----Original Message-----
From: mal hamilton
Sent: Saturday, July 23, 2011 10:28
To: rsgb_lf_group@blacksheep.org
Subject: LF: Re: Re: DL6NN on 137

Hi Minto
Let me know when you are QRV for a QSO on 137. CW will be satisfactory for
both ends with our power and mine
73 es gl
de mal/g3kev


----- Original Message -----
From: "Minto Witteveen" <minto.witteveen@gmail.com>
To: <rsgb_lf_group@blacksheep.org>
Sent: Friday, July 22, 2011 10:00 PM
Subject: LF: Re: DL6NN on 137


> Well, I am all for it..
>
> Now that we (PA) are kicked off of 500 KHz (again!) I needed another
> challenge. So 136 KHz it is.
>
> I have already built a PA for 136. My design is for > 1KW, I have only
> tested it at 650 Watt as my current power supply cannot handle more, and
the
> same goes for my dummy load.
>
> But I do have a 50 Volt 1.2 KW supply that should do the trick.
>
> I do not think QRP is an option on 137 KHz - especially with my antenna
(Mal
> wil probably concur :-) )
>
> Next step is building a variometer (3.5 to 4 mH), and the mixer/driver so
I
> can use my ft817 like in the 500 KHz setup.
>
> Don=92t expect met to appear on 136 any time real soon however,
unformtunately
> I do not have much time at the moment to complete the project. My target
is
> the end of August.
>
>
>
> For those interested: I have created a quick and dirty webpage with some
> info abt my experiment:
>
>
http://www.pa3bca.nl/index.php?option=3Dcom_content&view=3Darticle&id=3D22&=
Itemid=3D
16
>
>
>
> Regards,
>
> Minto pa3bca
>
>
>
>
>
> -----Original Message-----
>
> >From: Stefan Sch=E4fer
>
> >Sent: Friday, July 22, 2011 20:07
>
> >To: rsgb_lf_group@blacksheep.org
>
> >Subject: Re: LF: Re: DL6NN on 137
>
> >He seems to be new on the band. No other stations visible in the moment.
>
> >Surely it would be a positive impulse if new stations could get some
>
> >QSOs. This could start a positive spiral of activity. It's up to us...
>
> >DL6NN in JO30VC, OM Lutz. 99km distant to me, 250km to DF6NM.
>
> >73, Stefan/DK7FC, still in QSO
>
>=