Hi Markus,
Thank-you for your efforts. The pilot was generated using a raspi/ad9851
but there have been troubles with instability. Bypassing, shielding, etc
over the past few days yeielded no satisfaction and, sadly, a fried pi/SD
card! The arduino still works but the high precision math has to
be done on another machine as work continues on getting a replacement
pilot.
73 Joe VO1NA
PS Stefan's coil is very compact. 0,4 mm wire? Hope it can take the kV!
PPS Paul's article greatly apprectiated. Thanks!
PPPS All the best to all in 2017
On Sun, 25 Dec 2016, Markus Vester wrote:
Hi Joe,
today I found the time to look into your files from Dec 19/20 (1220xx08.txt
etc.). The pilot level is just right now. Assuming an accurate 10 MHz
DDS-clock, the theoretical pilot frequency would be 137499.999255 Hz,
consistent with the -0.8 mHz offset that I had found last time. This allows us
to determine the course of your RX center frequency, which apparently drifted
about 10 mHz upwards during that night (137499.8988 to 137499.9088 Hz).
Some of the files (e.g. 0708 and 0608, see png) showed phase jumps, which are
presumably due to occasional short audio dropouts in the soundcard processing.
In principle it should be possible to correct these glitches a-posteriori but I
have not attempted to do so. The 0308, 0408 and 0508 files looked good so I
calculated the expected offsets for Ric's transmit frequency and attempted
decodes. Unfortunately no useful result appeared yet.
LF DX conditions haven't been too good lately. But I'm sure that once they
improve, you will be able to pick up more than one European EbNaut station.
Best 73,
Markus
-----Ursprüngliche Mitteilung-----
Re: LF: EbNaut beaconing from JN64
Von: jcraig <[email protected]>
An: LF Group <[email protected]>
Datum: Mi, 21 Dez 2016 5:17 pm
Hi Ric,
The files are uploaded. Good luck to you and the other EbNaut experts
in your efforts to extricate your message!
73
Joe
-----Ursprüngliche Mitteilung-----
Von: jcraig <[email protected]>
An: rsgb_lf_group <[email protected]>
Verschickt: Di, 20 Dez 2016 7:11 pm
Betreff: Re: LF: EbNaut beaconing from JN64
Hi Ric, EbNauters,
SL txt files are available from last night. 12200008.txt 1200018.txt, etc.
rsNTP and a reduced amplitude pilot on 137.5 kHz were used. Files
will be uploaded on request.
73
Joe VO1NA
|
