From: MICHAEL WILLIAMS
To: Mineo Wakita
Date: Wed, 29 Nov 2017 22:42:14 -0500 (EST)
Mineo,
Attached is today's pass. I am also trying to determine frequency error
of converter, error of SDR, and error of my calibrator. Not an easy job.
In first attachment, SatPC-32 is running in the lower left corner.
SatPC-32 is controlling SDR. Red line is SATPC-32's computed Doppler
frequency. It looks like DTUsat-2 is coming in about 6 KHz lower than
SatPC-32 predicts using equipment here. I need to determine errors.
My down converter is at the antenna and converts 2401 to 145 MHz.
I found outside temperature changes the crystal oscillator's frequency
thus the converted frequency. The second attachment is my efforts for
predicting the Doppler.sqf. Normal steps was to check outside temperature,
use formula to calculate Doppler.sqf frequency, put calculated frequency
into Doppler.sqf file. This was successful with the FT-847. I was always
very close to DTUSat-2's signal at AOS. The graph's X axis is temp in F,
and Y axis is last two digits of frequency (2401.835 would be 35).
Is DTUSat-2 sending signals during eclipse?
If it is, I will start listening at night.
Good luck on your calculations.
73, Mike (K9QHO)
> On November 23, 2017 at 7:19 AM Mineo Wakita wrote:
>
> Hello Mike,
>
> I confirmed 2.4GHz signal from DTUsat-2 for the first time
> in a while since May. During that time I was repairing both
> the broken amplifier and the converter. It seems that there
> is no eclipse, so I heard a weak 2.4 GHz signal of DTUsat-2.
> The converter seems to be converted to about 16 kHz higher
> than before, so I will observe how much this difference is
> while repeating the experiment.
>
> 02:39-02:51 UTC, 23 Nov 2017, Ele 23 SW-W-WN, 2401.843MHz
> http://dl.dropbox.com/s/nvboxmudbvu2a0e/71123dt2.wav
> http://dl.dropbox.com/s/yo5b3qmgqncevf3/71123dt2.png
> http://www.ne.jp/asahi/hamradio/je9pel/dt2hory4.htm
>
> JE9PEL, Mineo Wakita