Message-ID: <005501cd6682$d5f99e20$0401a8c0@xphd97xgq27nyf>
From: "mal hamilton" <g3kevmal@talktalk.net>
To: <rsgb_lf_group@blacksheep.org>
References: <50092840.8010002@broadpark.no> <50095959.30204@iup.uni-heidelberg.de>
Date: Fri, 20 Jul 2012 14:20:37 -0000
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Subject: Re: LF: MFJ 259B HF antenna analyzer modification
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Another way would be to use a prescaler fed to the MFJ259B antenna socket.
This would avoid intrusive rewiring inside the analyzer.
This is what I was intending to do but I use other methods equally as good
to resonate the MF es LF es VLF antennas.
Signal generator/'Scope in series with the antenna loading coil has always
worked for me.

de mal/g3kev



----- Original Message -----
From: "Stefan Schäfer" <Stefan.Schaefer@iup.uni-heidelberg.de>
To: <rsgb_lf_group@blacksheep.org>
Sent: Friday, July 20, 2012 1:12 PM
Subject: Re: LF: MFJ 259B HF antenna analyzer modification


Hello Steinar,

Am 20.07.2012 11:43, schrieb Steinar Aanesland:
> Hi Stefan
>
> Is this the MFJ 259B HF antenna analyzer modification?
>
> http://www.we0h.us/Amateur_Radio_stuff/MFJ/MFJ-259B/LF-MF-Mods/
>
> la5vna S
>

Yes, this it is! Well documented by a few images. For LF i used a 10mH
fixed inductor (looking about like a resistor) and for MF i took a
FT50-77 and about 30 turns or so. A fixed inductor would work as well i
think. Just insert it and see what the range is...

73, Stefan/DK7FC



>
> Fra: owner-rsgb_lf_group@blacksheep.org
> [mailto:owner-rsgb_lf_group@blacksheep.org] På vegne av Stefan Schäfer
> Sendt: 19. juli 2012 01:55
> Til: rsgb_lf_group@blacksheep.org
> Emne: Re: LF: 630 meter full size dipole
>
> Hi Jay,
>
> Interesting, thanks for the info!! Yes and that could be a real
> alternative for those with a small garden and a stressing XYL. The wire
> for the dipole can be quite small and fits into a backpack.
> Then its a question of the dependency of the antenna efficiency as a
> function of the ground conductivity. This will be one of the interesting
> results!
> 10m above ground is not much for a 630m band dipole but if the
> difference to 2m above the ground is just a few dB, one can easily
> through out the wire during taking a walk and can do some MF /p
> operation, without a kite, without the need for a free field, without a
> tower, without a good earth (connection)... Many advantages! Maybe...
>
> BTW i have also modified (extended) the range of my MFJ 259B HF antenna
> analyzer to cover MF (313...658 kHz) and LF (103...209 kHz). This
> modification is done very easy! I'm not sure how accurate the
> measurements are in that range but maybe it gives me some ideas "where i
> am".
>
> Looking forward to that test!
>
> 73, Stefan/DK7FC
> Stefan
>
> This may be of interest for your next exploit ...
>
> Looking back in my 500 kHz log, I see that on 1/3/2010 I had a CW QSO
> with WD2XSH/35 in South Dakota ... who was running a full size 600 meter
> dipole. As I recall his antenna was relatively low at 30 or 40' above
> ground and he was running only 50 or 100 watts. His signal was weak but
> solid copy over the few nights that he was active. Distance was 1210 mi
> / 1950kM. Believe his antenna was 'out in the open' as he apparently
> owns a good sized farm.
>
> Jay W1VD  WD2XNS  WE2XGR/2
>
>
>
>
>