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information_for_astronomers:user_guide:signalpathsetup [2014/11/21 11:10]
bwinkel
information_for_astronomers:user_guide:signalpathsetup [2017/01/25 20:24] (current)
akraus
Line 1: Line 1:
 ===== Signal paths to the spectroscopic,​ VLBI, and pulsar backends ===== ===== Signal paths to the spectroscopic,​ VLBI, and pulsar backends =====
  
-There are several IF chains going to the Faraday room (where the backends live), most importantly the VLBA and narrow-band (SB) IF. Furthermore,​ the 21-cm 7-feed system has its own IF; and some receivers provide a 2+ GHz IF over optical fibers. All IFs are usually used with different bandwidth setups and need different attenuation to bring the power to a level which is appropriate for the backend ADCs. This is done using the so-called **MultiFiBa**.+There are several IF chains going to the Faraday room (where the backends live), most importantly the VLBA and narrow-band (SB) IF. Furthermore,​ the 21-cm 7-feed system has its own IF; and some receivers provide a 2+ GHz IF over optical fibers. All IFs are usually used with different bandwidth setups and need different attenuation to bring the power to a level which is appropriate for the backend ADCs. This is done using the so-called **MultiFiBa**. ​
  
 The various IFs coming from the receivers are fed into the 16-channel MultiFiBa, which allows to apply several internal bandpass filters and attenuation. Channels 1-7 and 9-15 is almost exclusively used for the 21-cm 7-Beam system. All other receivers are attached to channels 8+16. For each channel the **mode** can be changed with the command The various IFs coming from the receivers are fed into the 16-channel MultiFiBa, which allows to apply several internal bandpass filters and attenuation. Channels 1-7 and 9-15 is almost exclusively used for the 21-cm 7-Beam system. All other receivers are attached to channels 8+16. For each channel the **mode** can be changed with the command
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 ^Mode^Channels^IF name^IF range^Bandwidth^Attenuation^Comments^ ^Mode^Channels^IF name^IF range^Bandwidth^Attenuation^Comments^
 ^ ^ ^ ^[MHz]^[MHz]^enabled^ ^ ^ ^ ^ ^[MHz]^[MHz]^enabled^ ^
-|249|8+16|VLBA IF|700-800|100|yes| |+|216|8+16|VLBA IF|700-800|100|yes| |
 |185|8+16|VLBA IF|500-1000|500|yes| | |185|8+16|VLBA IF|500-1000|500|yes| |
-|128|8+16|Narrowband (SB)|100-200|100|yes| | +|000|8+16|Narrowband (SB)|100-200|100|yes| | 
-|134|8+16|Narrowband (SB)|150-200|50|yes|needs change in .front-files (ULO)|+|006|8+16|Narrowband (SB)|150-200|50|yes|needs change in .front-files (ULO)|
 |128|1-7,​9-15|7-Beam IF|100-200|100|yes|exclusively for 21-cm 7-beam| |128|1-7,​9-15|7-Beam IF|100-200|100|yes|exclusively for 21-cm 7-beam|
 |161|1-7,​9-15|7-Beam IF|0-300|300(*)|yes|exclusively for 21-cm 7-beam| |161|1-7,​9-15|7-Beam IF|0-300|300(*)|yes|exclusively for 21-cm 7-beam|
information_for_astronomers/user_guide/signalpathsetup.1416564624.txt.gz · Last modified: 2014/11/21 11:10 by bwinkel