WR-G35DDCi Multichannel Coherent Application Guide for Extended topology configuration (ETC)
20
For interconnection,
only use the original WiNRADiO 30 cm SMA sampling clock
patch cable
supplied with the ETC Kit, as it is specially matched to be coherent.
Picture 2-18:
The 30 cm SMA sampling clock patch cable
2.3.9 SMA coaxial cables for external connection of the sampling
clock and synchronization
There are two long SMA coaxial cables supplied with the ETC Kit (shown in the Picture 2-19).
Both cables are almost identical, but differ in purpose and connection. The cables are
distinguished by a labelled sticker attached to them.
First cable is called the
CLOCK CABLE
(see Picture 2-19 and 2-20 on the left) and is used to
distribute the sampling clock from the Coherent clock generator board of the Clock Kit to all
WR-G35DDCi receivers which are in the coherent group.
The other cable is called the
SYNC CABLE
(see Picture 2-19 and 2-20 on the right) and is
used to link the receivers in a daisy chain like manner, to synchronize the receivers for
coherent operation. Each SYNC CABLE has the delay value specified on its sticker. The delay
value is marked as “DELAY n CLK” where ‘n’ is an integer number, which specifies the
amount of sampling clock cycles by which the cable delays the signal.
These cables can be manufactured in various lengths; however, the length is not arbitrary.
As mentioned above, the length of the cable is marked on the sticker of the SYNC CABLE in
by the number of sampling clock cycles which it delays the signal. Shortest cable has a delay
of 2 sampling clock cycles and is approx. 0.8 metres long. The longer cable has a delay of 3
sampling clock cycles and is approx. 2.8 metres long. If longer cables are needed, please
contact WiNRADiO.
All cables used for coherent operation of receivers must be the same length and type in the
ETC configuration. Cables of various length and/or types cannot be mixed within one
coherent group of receivers. Also, the user must specify the delay of the SYNC CABLE in the
software, so the software can compensate for the delay.
