Instruction manual

ACU-1000 Operations Manual
7-4
7.4.3 PTT Circuit
The PTT circuit is now active low. This means that many popular types of headsets can be
used without having to modify the headset circuit as was previously required.
7.4.4 HSP-2A DB-15 Connector Interface
The DB-15 on the rear panel for the HSP-2A can be configured to have the same pinout as a
DSP module.
• Jumper JP10 changes DB-15 pin 6 from either being speaker output as it was before, or
GND (TX B) so that the HSP will work with a radio or more likely an NXU-2A.
• The old HSP-2 was wired such that pin 9 could be used for an active high COR; it is
now Active low in HSP-2A.
COR input can now go to pin 13 (which is the same as the DSP modules), or it can go
to pin 9 for any legacy HSP issues.
COR on the HSP-2A is supplied standard with active low input on Pin 13 which is the
same as a DSP connector.
For legacy applications, COR input can be connected to Pin 9 by installing a zero Ohm
jumper R146. In addition, pin 13 on the old HSP was /AUXI3, so jumper options are
available to give the user an option to make pin 13 be either COR or /AUXI3 as shown
in the chart below.
Pin #
Function
R144
R145
R146
13
COR
IN
OUT
OUT
13
/AUXI3
OUT
IN
NO EFFECT
9
COR
IN
OUT
IN
9
COR
OUT
IN
IN(For Pin 13 to be /AUXI3
concurrently
Table 7-3 COR Jumpers
From the factory, R145 and R146 are not installed in the HSP-2A
7.4.5 External Speaker
The HSP-2A is supplied standard with a large, high efficiency, outboard speaker.