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authorAndreas Eversberg <jolly@eversberg.eu>2017-12-04 14:12:11 +0100
committerAndreas Eversberg <jolly@eversberg.eu>2017-12-09 20:46:14 +0100
commit9f901384deda96a7dd021923841885ec1e4f2d67 (patch)
treea6bd7a6c611796369f0c1a7f9ddfd7bfe90da08a /docs
parentc49ee3b2a8c545ce6582b414b55ed9f610bd4b94 (diff)
SDR: Add option to set local oscillator (LO) offset
By default it is set to -1 MHz.
Diffstat (limited to 'docs')
-rw-r--r--docs/sdr.html10
1 files changed, 3 insertions, 7 deletions
diff --git a/docs/sdr.html b/docs/sdr.html
index 03bf8e1..687a10e 100644
--- a/docs/sdr.html
+++ b/docs/sdr.html
@@ -77,9 +77,7 @@ In case of B-Netz, I use the following parameters:
# bnetz --sdr-soapy \
--sdr-tx-gain 50 \
--sdr-rx-gain 30 \
- --sdr-bandwidth 5000000 \
--sdr-samplerate 5000000 \
- --sdr-tune-args "OFFSET=1000000" \
-s 100000 \
-k 17
@@ -89,10 +87,10 @@ In case of B-Netz, I use the following parameters:
In order to change from analog sound card to SDR, you need <b>--sdr-soapy</b> option.
In my setup I use antennas directly connected to the SDR.
Being about 1-10 meters away, I use the <b>gain</b> as defined above.
-The IF filter requires a minimum <b>bandwidth</b> of 5 MHz.
The <b>sample rate</b> must be 5 MHz minimum.
+The default <b>bandwidth</b> follows the sample rate, if not specified using <b>--sdr-bandwidth</b>.
Higher sample rate causes more CPU, RAM and USB load.
-The local oscillator frequency causes the transmitted signal to be noisy, so I shift it 1 MHz away, using an <b>offset</b>.
+The local oscillator frequency causes the transmitted signal to be noisy, so I shift it 1 MHz away, using the default <b>--sdr-lo-offset</b>.
The audio processing rate of 100 KHz (<b>-s 100000</b>) is used to generate two channels: <b>17</b> and 19.
Note that channel 19 is not given here, but will be used automatically.
With B-Netz, the transmitter switches from any voice channel to the paging channel (19) whenever the phone gets paged.
@@ -174,9 +172,7 @@ Because C-Netz uses only odd channel numbers for 10 KHz spacing, we use channel
# cnetz --sdr-soapy \
--sdr-rx-gain 50 \
--sdr-tx-gain 30 \
- --sdr-bandwidth 5000000 \
--sdr-samplerate 5000000 \
- --sdr-tune-args "OFFSET=1000000" \
-s 100000 \
-k 131 -k 135 \
-C 0,0
@@ -192,7 +188,7 @@ Give PAL 'FUBK' test image on TV channel 21.
# osmotv --sdr-soapy \
--sdr-tx-gain 60 \
- --sdr-tune-args "OFFSET=-3000000" \
+ --sdr-bandwidth 60000000 \
-r 13750000 \
-c 21 \
tx-fubk