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The Array Solutions QSK-MASTER is a 160-6 meter 2500 watt external QSK switch.  Internal strapping options include amplifier polarity keying sense, 120/240VAC powering, and turn-off time delay to ensure that the QSK-MASTER is compatible with any transceiver/amplifier combination.  And the QSK-MASTER’s low current keying interface means that it can be directly keyed by your transceiver without requiring a separate external transceiver/amplifier interface.  For maximum reliability the QSK-MASTER is relay-based, using a high-speed signal relay for transceiver and bias switching, and a sealed high current/high speed  relay for amplifier output switching.  This means that the QSK MASTER is essentially lossless, so no optional fan is needed for high duty-cycle operation.  And the QSK-MASTER cannot be damaged by any sudden high SWR event even when operating at maximum power.  As demonstrated in the figure below, the relays switch in less than 5ms (typically less than 3ms) ensuring relay operation is faster than the “amp-enable-to-RF output” delay of your transceiver. 

Upper trace:     Amplifier output relay            Lower trace:     Transceiver/bias relay

Trigger: Transceiver amp-enable output         Keying speed:  80WPM 

QSK-MASTER Specifications:

RF Power capability:    2500 Watts CW/SSB/Data Modes

Frequency Range:         1.8-54 MHz

Residual SWR: Typically <1.1:1 from 1.8-54 MHz

Insertion Loss:              < 0.1 dB  

Keying Input:                Selectable:  Closure to ground (default), or +12V amp enable output.  Less than 3ma sink (ground) or source (+12V). 

Enable Delay:               Less than 5ms, typically less than 3ms from amp enable control.

Disable Delay:              Less than 5ms, typically less than 3ms from amp disable control.  Strappable for 10ms turn-off delay.

Power Required:           120/240VAC strappable, 120VAC default

Relay Lifetime:             New Version using High Speed Signal Relay: >100 million operations

Dimensions:                  3”H x 6”W x 3.5”D

Weight:                        1-1/2 pounds

Optional Cables:           IC7 for IC-706 and IC-7000 (solid-state amp key and ALC)

                                    K480 for TS-480 (solid-state amp key and ALC)

                                    K2K for TS-2000 (solid-state amp key and ALC)

                                    FT1K for FT-1000D/MP/MKV/2000/9000 (solid-state amp key)

                                    Other cables available on request

The QSK-MASTER and amplifier are connected as shown in the figure below.  Note that the amplifier keying input is always shorted so the amplifier is enabled whenever it is in the OPERATE condition. 

Transceiver

XCVR

To AMP

From AMP

ANT

Key

Bias Cntrl

AMP

QSK-MASTER

AMP key

ALC

Figure 1:  QSK-MASTER Interconnect Block Diagram

RF In

RF Out

AMP Key  Inp.

The amp-enable output of typical transceivers is provided through a RCA (phono) connector output, so a standard RCA mono cable is all that is necessary for these transceivers.  Best QSK operation results when using your transceiver’s solid-state amp-enable output, not a relay-based amp-enable output.  For transceivers without a solid-state RCA amp-enable output (Yaesu FT-1000/MP2000/9000, IC-706/7000, Kenwood TS-480/2000, etc) you can construct your own solid-state interface cable or purchase a pre-made cable from Array Solutions. 

The QSK-MASTER is extremely flexible.  Besides internal straps that set the amplifier keying polarity and 120/240VAC operation, the QSK-MASTER includes a strap to add additional turn-off delay.  While most transceivers disable the amplifier only after the transceiver’s RF output has decayed to zero, some transceivers disable the amplifier before the RF has decayed to zero (notably the IC-706MKIIG, IC-7000, some older ICOM transceivers, TenTec Omni V and possibly other transceivers).  This usually shows up as key-clicks.  If you have reports of key clicks on your signal or notice them on a separate receiver, strapping the QSK-MASTER for the additional turn-off delay will resolve this.

The QSK-MASTER can also control your amplifier’s bias current if desired.  However, amplifier bias control is optional as you can elect to tolerate the extra power dissipation of the amplifier when the amplifier function switch is in the OPERATE position.  To control your amplifier bias with the QSK-MASTER, you must break the bias control voltage inside the amplifier and feed it to the 3.5mm stereo BIAS jack on the QSK-MASTER. 

The QSK MASTER is also a perfect QSK T/R Switch for Boat-Anchor Stations!

If you are into nostalgia and have a classic boat-anchor station consisting of a separate transmitter and receiver, the QSK MASTER can also serve as the perfect T/R switch for your set-up.  Connect your receiver to the QSK MASTER’s TRANSCEIVER port, connect your transmitter to the QSK MASTER’s FROM AMP port, and connect a keying line between the QSK MASTER’s BIAS port and your transmitter’s key input.  Finally, connect a shorting PL-259 to the QSK MASTER’s TO AMP port.  Your key/bug/keyer keys the QSK MASTER directly.  Refer to Figure 2 below:

QSK-Master Manual - Older Vacuum Relay Style

QSK-Master Manual - Newer Signal Relay Style (this is the unit were shipping as of Sept 10, 2009)

QSK-Master FAQ - answers to questions

Easy to hook up. Easy to control the bias. Great QSK controller. I am now using the QSK Master on Henry 3KA, BTI, and an original Alpha 76. All modified to allow easy bias keying by QSK Master to keep the tubes cool. No moving parts in the amps anymore. 

W5KU