DRM Software Radio Forums

DRM Software Radio Forums (http://www.drmrx.org/forum/index.php)
-   Reception Results - Recent Posts (http://www.drmrx.org/forum/forumdisplay.php?f=22)
-   -   HCJB on 11625 kHz/ 15360 kHz/ 15350 kHz from Pifo to Europe (http://www.drmrx.org/forum/showthread.php?t=1932)

mitajohn 15-06-2008 22:29

June 15
2 Attachment(s)
Hi all,

An unattended log. Not bad.

maxpower 16-06-2008 11:15

2 Attachment(s)
Some weak parts here at the first half hour and later (10 minutes at 21.25 UTC) . the rest was ok, best signal at the end with about 20 dB SNR.

Digger 16-06-2008 14:33

15th June
1 Attachment(s)
Almost one hour with much more audio than I have been used to for a long time.

Digger 16-06-2008 21:10

1 Attachment(s)
Things seem to improve a lot after a 30 minutes long weak start. I had to stop the log around 2110 UTC.

maxpower 17-06-2008 09:28

1 Attachment(s)
I played a little bit arround with the SDR in order to find out some overloading problems. So my log starts (late) at 20.23.
Some problems here and there but overall a good result with SNR from 10 to 18 dB.


mitajohn 17-06-2008 13:11

June 16
2 Attachment(s)
Hi all,

An almost perfect result (SQ: > 99%), SNR max ~18 dB, but decoding possible even around 12 dB.

mitajohn 17-06-2008 23:29

June 17
2 Attachment(s)
Hi all,

Until 21:30 was an almost perfect result then conditions changed with severe decoding problems.

maxpower 18-06-2008 16:09

1 Attachment(s)
I think I'll have to narrow the possible bandwidth from >200 to about 100 kHz (which should be enough for most of the soundcards available), because reception suffered a little bit from overloading due to a TX at 15425(?) kHz yesterday.

But, however, good reception at least from 21.00 UTC to 22.00 UTC.


simone 18-06-2008 20:17

1 Attachment(s)
Quite good results in the second hour last night.

maxpower 19-06-2008 08:51

1 Attachment(s)
Propagation window opened late yesterday evening. But when signal gets up, it gets up fast. :D


mitajohn 19-06-2008 22:16

June 19
1 Attachment(s)
Hi all,

Until 20:40 the result was good then turn to very bad.

Digger 20-06-2008 05:42

19th June
1 Attachment(s)
Here it looked different: The first hour was more or less a total loss, but the last 60 minutes resulted in 99.5% CDA.

maxpower 20-06-2008 09:33

2 Attachment(s)
My reception has been more like Diggers, too. But times were a little bit different.


20.00 - 20.30: almost no audio
20.30 - 20.40: Fade in
20.40 - 22.03: very good reception with 99.57% correct decoded audio

Btw: While looking at the spectrum-display: Is it possible that reception changes from a 3 hop to a 2 hop reception due the transmission at my location because F-Layer gets higher towards the night?

I read at the "Woofferton to Ascension"- Thread that this TX needs 3 hops to get to Ascension Island (at 16m).

I watched the DRM Waterfall of the HCJB DRM Transmission (with one eye while watching the soccer game yesterday evening with the other).
Usually fading it is completly "wild" at the beginning of reception and SNR gets up to max 14-16 dB (most times only 12 - 14 dB). (3 hops?)
Towards the end of transmission the waterfall is much more clearly (and SNR is much higher). (2 hops?)

Apart from that I can see a SNR-"valley" somewhere in the middle of good reception quite often (at some days it's very heavy). After that SNR gets up to the best values of the evening at most days.

Hmm, if this is right does the "SNR over time" chart show that the loss of one hop (the third one) is about 3 - 8 dB?
This could also explain why reception has been better (=stronger) at the early morning (-> F layer is higher after night and two hops are enough to get across the distance) :confused:


Digger 21-06-2008 08:15

20th June
1 Attachment(s)
Questionmark... :confused:

Digger 21-06-2008 22:52

1 Attachment(s)
Back to "normal" again. The second hour was almost perfect.

All times are GMT. The time now is 14:20.

Powered by vBulletin Version 3.5.3
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.