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An Elecraft K2 anchors this portable station that covers all HF bands plus 144, 222, 432, 903, and 1296MHz bands.  Operational simplicity is the rule - performance and portability are the objectives.

 

Updated White Paper (May 2006) on the construction of this station, including schematic drawings.

Original White Paper (April 2004) on the construction of this station, including schematic drawings.

Presentation given at the October 2004 PNW VHF Society Conference

 

An oak box with aluminum shelving make a rugged enclosure for a complete self contained pre-wired system that works in the home and travels quickly to the Rover vehicle for contests or Field Day.
 
Pictured on the left side are an Elecraft K2, Elecraft XV144 144MHz, XV222 222MHz, and XV432 432MHz transverters, a 1296MHz DEM transverter, and 903MHZ DEM transverter.   

Not shown here sitting on the top of the box are a 100W 903MHz surplus amplifier and a 60W surplus 1296MHz amplifier.   Behind and to the left of the front speaker is a 16W 1296MHz amplifier set up for 0.5W input, 6W output to drive the large amplifier.   T/T relays are inside the back connector panel.

The Mirage B108 is an 80W 2M amp, and the small grey box next to the amp is the Elecraft KRC2 band decoder.

 
The antenna bulkhead connector panel brings out common RF for all VHF+ bands.  For 1296 and 903MHz band antenna connectors I use split TX and RX.

RCA connectors on the left are for amplifier PTT and external home antenna tower T/R switch/sequencer control.  The 1296 PTT circuit is broke out to 2 connectors so that a sequencer can be inserted in between the KRC2 and 1296 transverter.  the transverter aux relay drives the T/R switch.  The switch has 2 aux contacts that enable the 16W driver amp bias and 60W 1296 amp PTT. The 1296 connector is actually part of a 12V N type T/R relay. The 16W 1296 driver amp is not visible since it is behind the panel.

The XV144 does double duty as the 144MHz IF.  I will sometimes use this setup to drive external 300W or 150W amplifiers on 2M, and a 120W amplifier on 222MHz.  Not visible is a RIGRunner 5 position DC power panel.

For the 903 amp I use 24VDC with uniquely mated Power Poles so I do not mix 12 and 24VDC accidentally.  The 903 TX/RX relay is the top connector mounted behind the and on the panel. It is controlled by the DEM 903 transverter aux relay wired to 13.8VDC.   Same as for the 1296, except .  The 903 amp is not PTT switched.

The 144MHz common IF for 903 and 1296 and 2M is switched by a 12VDC TTL logic level SMA SP4T switch and is controlled by the KRC2. SMA connectors are used to reduce size.  Quality cabling and RF switches maintain high isolation. Quality Teflon cable is used for interference reduction in high RF environments and eaking out those weak signals.

 I use RG-316/U for flexibility, and RG-142/U where more power and extra RF shielding is involved.  All antenna connectors are easily accessible on the back panel.   

Not pictured: A 900MHz isolator is used on the output of the 903 100W amplifier.

The K2 slips out easily for regular HF QRP duty.


I am using the Elecraft K60XV 60M and Transverter Interface option to bring out a low level 28MHz IF signal (about 1mW) from the K2. The interface is automatically enabled (thus disabling the PA in the K2) when one of the 5 transverters are selected. RG-316/U cabling with BNC and SMA connectors is cut to fit to daisy chain the split 28MHz IF and RF ports.
 
The Elecraft KRC2 is modified slightly to enable automatic switching for the 144MHz common IF path and PTT routing. The K2 gives easy band control with direct calibrated frequency display and 1 button band change capability with stored max power level for each transverter removing the need for external attenuators to be switched in and out. HF switching is preserved though the internal K2 ATU ports.