Editing SimTX Guide/Receiving

{{SimTX Guide navigation}}
The '''Receive''' tab starts a receiver on the server and passes its signal to an SDR program on your computer through a '''bridge'''. The setup is on the left; the '''Bridges''' list is on the right.

== Receive a signal ==
[[File:SimTX Guide Receiving receive tab.png|thumb|center|800px|alt=Receive tab with My station selected, Receive at Demo hilltop, the Roof Yagi antenna and its rotator, center frequency 14.2 MHz, sample rate 250000, and a running bridge Hilltop 20 m on 127.0.0.1:1234.|The Receive tab receiving at Demo hilltop, with one bridge running.]]
# Under '''Where you listen''', choose where the receiver is.
# Under '''Tuning''', set the '''Center frequency''' and the '''Sample rate (Hz)'''.
# Press '''Start RX'''.
# In your SDR program, connect an rtl_tcp source to the address shown under '''Bridge''', by default <code>127.0.0.1:1234</code>.

[[How to receive]] shows the settings in SDR++, and [[Guide to setting up sdr console with simtx|the SDR Console guide]] in SDR Console.

== Where you listen ==
{| class="wikitable"
! Choice !! Receiver !! Needs
|-
| '''My station''' || One of your stations: choose it under '''Receive at''', with its '''Antenna''' and '''Radio'''. || Sign-in
|-
| '''Public station''' || Another account's public station. Search under '''Find a public station''' and select it. The session uses the station's main antenna. || Sign-in
|-
| '''Ad-hoc''' || Any location, with a '''Callsign''' and '''Antenna''' of your own. || Nothing
|}

For '''Ad-hoc''', type the '''Latitude''' and '''Longitude''' or press '''Pick location on map'''. '''Antenna details''' sets the antenna's length, '''Height (m)''', '''Azimuth (°)''' and '''Feedline loss (dB)'''.

'''Receive here''' in a station's details in the '''Stations''' tab chooses that station. On your own station, '''Track a satellite''' and the '''Rotator''' work as for transmitting; see [[SimTX Guide/Rotators and tracking|Rotators and tracking]].

== Tuning ==
{| class="wikitable"
! Field !! Meaning
|-
| '''Center frequency''' || The middle of the band you receive.
|-
| '''Sample rate (Hz)''' || The width of the band, in samples per second. 250,000 suits shortwave; FM broadcast needs about 1,024,000 or more.
|}

'''Tune RX''' next to a transmission in a station's details sets the center frequency to it.

== Bridge ==
{| class="wikitable"
! Field !! Meaning
|-
| '''Label''' || A name for the bridge in the '''Bridges''' list.
|-
| '''Listen address''' || Where your SDR program connects. <code>127.0.0.1</code> is this computer only. <code>0.0.0.0</code> lets other computers on your network connect, and anyone there can retune it.
|-
| '''rtl_tcp port''' || The port your SDR program connects to. Default 1234.
|-
| '''Hardware profile''' || The RTL-SDR model the bridge presents to your SDR program. Default Generic R820T.
|-
| '''Timestamped role''' || Adds a timestamp to each block of samples. Your SDR program gets the same samples.
|-
| '''Digital AGC''' || Starts the bridge with digital automatic gain control. On by default.
|}

== Link resilience ==
'''Smooth over network dropouts''' adds a jitter buffer, retries and concealment of short dropouts. It is on by default. '''Advanced tuning''' sets:
{| class="wikitable"
! Field !! Default
|-
| '''Read timeout (ms)''' || 5000
|-
| '''Max retries''' || 3, or -1 for no limit
|-
| '''Retry base delay (ms)''' || 250
|-
| '''Jitter buffer (ms)''' || 150, or -1 for off
|-
| '''Narrow upstream on repeated stalls''' || Lowers the sample rate when the link keeps stalling.
|}

== Bridges ==
[[File:SimTX Guide Receiving bridge.png|thumb|center|792px|alt=Bridges list with one bridge, Hilltop 20 m, Running, 14.2000 MHz, 250.00 kS/s, 127.0.0.1:1234, on Demo hilltop with the Roof Yagi, and a Stop button.|A running bridge in the Bridges list, with the address for the SDR program.]]
Each '''Start RX''' adds a bridge to the list, with its frequency, sample rate, address and state: '''Starting''', '''Running''', or ended. A line of link figures appears after trouble: reconnects, underruns, concealed blocks, narrowing and dropped blocks.
* '''Stop''' ends one bridge, '''Stop all''' every bridge after you confirm.
* '''Clear finished''' removes ended bridges.

== Presets ==
'''Presets''' at the top saves and loads complete receive setups, the same way as on the [[SimTX Guide/Transmitting#Presets|Transmit tab]].

[[Category:SimTX Guide]]