Message-ID: <1578680246a.marcocadeddu@tin.it>
Date: Sun, 2 Oct 2016 19:45:27 +0200 (CEST)
From: "marcocadeddu@tin.it" <marcocadeddu@tin.it>
To: <rsgb_lf_group@blacksheep.org>
Mime-Version: 1.0
Subject: R: LF: IK1HSS - DF6NM WSPR 137 kHz ...errata corrige
Content-Type: text/plain;charset="UTF-8"
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org
Content-Transfer-Encoding: 8bit
Status: O

Hi Andy,

just a small correction to the datas of previous message.. time lapses 
and my memory sometimes misses something...
Rechecking my papers I recalled that I made some change in my 
RF ammeter in the shack, formerly it had 2 ranges 3 and 1 A fs then I 
changed the trimming (without etching a new label) and now it reads 4 
or 0,5 A fs!
So antenna current is something more than 0,5 A and with the venerable 
Marconi TF2604 this afternoon I found that RF voltage is 38 Vrms, on 56 
ohms of impedance (in the shack) brings to abt 0,6 Arf or 25W feeding 
the antenna. EIRP should be 13 - 14 dBm.

Hope this evening you can copy me ;-)

73 Marco IK1HSS

----Messaggio originale----
Da: marcocadeddu@tin.it
Data: 2-ott-2016 13.12
A: <rsgb_lf_group@blacksheep.org>
Ogg: R: LF: IK1HSS - DF6NM WSPR 137 kHz

Hello Andy,

sorry for the local QRM, the neighbors of Markus are more fair.. hi
May be later they have a short sleep and conditions improve :-)
I have never made measurements of current at the antenna base, it is a 
bit complicate because it is on the roof of the house (or according 
the 
definition of a friend on the Saratga deck), just recorded impedance 
plots with my N2PK VNA. If I have to trust on my RF ammeter in the 
shack (about 40m of coax away) it should be in the range of 1A but I 
guess it is peak not rms. The antenna is fed via a transformer made 
with 2 stacked FT 240-43 N1=20T and N2=14T (2:1 transformer) and 
neglecting the small transformation given by transmission line the 
impedance at resonance including all losses is close to 25 ohm. Of 
course this nice reading is due to my single radial.. or the Saratoga 
deck: the roof is made of sandwich panels (about 700  sqm at 35m from 
the ground) and I spent some time placing jumpers between quite all 
the 
panels ;-) so the measured impedance is very close to the simulated 
impedance on good ground.

Just for fun could send you by mail some pictures ;-)

Hope to see later your reports

73 Marco

----Messaggio originale----
Da: f6cni@orange.fr
Data: 2-ott-2016 11.58
A: <rsgb_lf_group@blacksheep.org>
Ogg: LF: IK1HSS - DF6NM WSPR 137 kHz


Hello Marko.

I was just trying for the first time to copy your LF WSPR signal. But 
I 
am sorry, I have a bad local QRM just on your QRG of 137453.

I’ll try again later if this QRM gone away, HI !

Just a question about your nice antenna : dou you use for the earth 
groud some radials or ground rods ? And, did you had a mesurement on 
your base antenna current ?

Bets 73.

Andy.


-----Message d'origine----- 
From: marcocadeddu@tin.it 
Sent: Sunday, October 2, 2016 11:22 AM 
To: rsgb_lf_group@blacksheep.org 
Subject: LF: IK1HSS - DF6NM WSPR 137 kHz 

Hello Markus,

apparently this morning there is a Turin-Nuerberg duct!
I'm running my WSPR beacon on 137 kHz since friday evening with no 
interruption, same power, same rig, same antenna, but yesterday you 
missed again my sigs after the sunrise, today at 11AM (0900 UTC) you 
are still copying me although a small hole from 0444 and 0626 UTC.
The TX output is about 30W (I have to measure better....) The antenna 
is a 10m wire vertical (2m on the side of my metal mast) with 100m of 
tophat (10 sloping wires 10m each) with a topcoil resonating on 470kHz 
(not yet tuned I have to take away some turns in the coil) and a base 
coil resonating at 137 kHz. Yesterday afternoon we had a couple of 
hours of rain, but small retuning with the variometer were enough to 
keep the antenna at resonance) :-)
I'll keep on the transmission being very curious to see how long you 
can decode even if the SNR is not impressive..

73 de Marco IK1HSS