Overview

SSB Electronic DCW 2004 B Sequence Controllers

SSB Electronic DCW 2004 B Sequence Controllers provide properly timed power to remote mast-mount preamplifiers, as well as timed keying for RF amplifiers and transverters. Designed for convenient remote powering of SP and MHP series preamplifiers via the coaxial cable, the integrated sequential control reliably prevents sensitive preamplifiers from being damaged by RF peaks during switching operations. For the control of external devices, the DCW 2004 B provides three switching outputs with increasing delay times, so other components can be activated in a defined sequence.

Features of the DCW 2004 B Sequence Controller:
• Remote power (bias tee) via the coaxial cable for SP and MHP series Preamplifiers.
• Delayed switching of RF linear amplifiers.
• Three sequentially controlled switching outputs.
• PTT input for switching to ground or +5 to +12 VDC.
• Independent switching of preamplifier and power amplifier.
• Low insertion loss of only 0.1 dB and high shielding effectiveness.
• Automatic short-circuit test of the preamplifier feedline.
• Last-State Function stores the previously selected operating mode.

Please note: Extended Connections diagram must be used for proper keying delayed sequencing (see the diagram in the Documentation link).
Advance keying is required for SSB mode with a footswitch, or for CW mode an external keyer with a PTT output, which must be connected to the sequencer (via pin 3 in and pin 1 Ground).
With these initial Ground on Transmit PTT signals, each output is delayed by 200ms, 250ms and 300ms respectively:
First, the sequencer removes bias tee coax DC power to the mast-mounted preamplifier;
Second, it keys the amplifier (via pin 5 out);
Third, it keys the transceiver (pin 6 out) or transverter.
Fourth, the extra relay output on pin 7 for the transceiver if a transverter is used.
Upon release of PTT input, all outputs release immediately, except for an additional 200ms delay before power is restored to the receive preamplifier.
Due to timing delay of transmitter keying, CW mode keying of the transceiver cannot use VOX.

Technical Specification of the DCW 2004 B:

- Operating Power: 12 – 14 VDC, 2.1mm center positive
- Band Coverage: 6 m, 4 m, 2 m, 1.25 m, 70 cm, 33 cm, 23 cm
- Power Handling (Digital, CW & Phone):
- 6 m / 1500 W
- 2 m / 1500 W
- 70 cm / 800 W
- 23 cm / 400 W

- Insertion Loss: 0.1 dB
- Preamplifier Power (bias tee): 13.8 V max 500mA load
- PTT switching output: 30 V at 500 mA max.
- Relay switching outputs: 30 V at 500 mA max.
- Ground On Transmit Voltage PTT Input Threshold: < +2 V
- Positive Voltage PTT Input Threshold: > +5 V
- Dimensions (WDH): 5.512 x 4.724 x 2.087 in. (140 x 120 x 53 mm)

Documentation