SCS PTC-IIex, Manual

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14 Circuit Description
14.4 The Indicator Unit
The LED indicators are built up using modern SMD combined with lightguide
technology. A additional display board as used within the PTC-IIpro could be eleminated
this way. The lighting console consists of 8 2-colored LED´s and a 15 LED tuning
indicator. A multicolored frontpanel printing eases the assignment of the LED´s to the
various functions of the PTC-IIex.
14.5 The Construction
The PTC-IIex is made up of a single printed board of 100*160 mm. This board is a six
level multi-layer construction, and contains internal ground and supply voltage areas. On
the back is the DC input, an ON/OFF switch, an 8 pin DIN socket for the transceiver
conection, as well as a 9 pin SUB-D socket for the terminal connector. The construction
is largely SMD.
Every single pin of every socket has its own T-filter, in order to improve the HF rejection
in strong RF fields, as well as to prevent unwanted radiation of electromagnetic energy.
This method is not only used to meet the restrictions of the government, but it is used in
practice as well. The PTCplus, decoupled with the same method has furnished proof to
bear up under the electromagnetic pulse of a nuclear explosion (tested by 50kV/m field
strength in a NEMP simulation plant of the German armed forces). The whole is enclosed
in an aluminium profile case. Both front and rear of the case are multicolored printed.
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