Ham Radio Set Up on a Sailboat

 

Yaesu FT-981 on a 38' Sailboat 

HF Transceiver

FT-891 remote head unit

The HF radio system on Johanna Rose consists of an amatuer radio HF transceiver, a split backstay antenna, an antenna autotuner, and a RF coupled ground system.  The HF transceiver is a Yaesu FT-891 The Yaesu FT-891 is a HF/50MHz all mode mobile transceiver with 100W of transmit power.  Yaesu is one of the world leaders in radio transceivers.  I considered several other radio options, but the FT-891 is a great performing radio with extended capabilities and function  and ended up being the best value in today's market.   The radio is powered via the 12VDC house battery bank via a 25A breaker.   The detachable front panel of the FT-891 was mounted on a bulkhead by the campanionway in the aft cabin area.  The main transceiver was mounted a short distance away high up in the portside quarter berth area. 

FT-891 base unit, Signalink unit,  and Raspberry
Pi4B computer.  Also shown is the DIY remote
control for the SG-239.

Antenna & Ground/CounterPoise System

RF ground coupler
(7@0.1 uF capacitors)

SGC SG-239 auto-tuner mounted
in weatherproof enclosure inside
the transom

The stainless steel backstay is uses as a long random wire antenna.  A Sta-Lok backstay insulator was installed about 45ft up the stainless steel backstay.  The bottom of the backstay connect to a chainplate which is bolted internally to a fiberglass support-knee in the transom.   I considered several autotuner options, but after reading many reviews, I went with the SGC SG-239 auto-tuner as it has a great reputation, great price, but more importantly it can be mounted at the antenna base and monitored/controlled remotely.  The  SG-239 was installed in a weatherproof enclosure mounted in the transom.  A RG-58 cable with PL-259 connectors connect the FT-891 to the SG-239 auto-tuner.   The auto-tuner antenna output is connected to a chainplate bolt using a 5 inch 10AWG wire and ring terminals.  The auto-tuner antenna ground uses a 1-1/2inch tinned copper braid connecting the SG-239 to a bronze seacock through a RF coupler providing a RF pass but DC block.  The RF coupler was made by cutting the copper braid just before the bronze seacock and reconnected the two end via a block with 7 capacitors in parallel (0.7 uF total capacitance).  

RF grounding to seawater via bronze seacock.

Auto-tuner antenna output to backstay.

Backstay with antenna insulator ~4' from top

Sta-Lok insulator installation

Digital Communication Devices

Digital communications, including sending and receiving SSB emails requires either an expensive hardware modem or a computer sound card and software to provide modem functionality.  The latter has come about from rapid advances and community development in the Ham community.  While software equivalent modems do not yet have the same data transfer rates as the latest Pactor 4 modem, the gap is rapidly narrowing.  This is quite remarkable given that a P4 modem coast over $2,000 whereas the software equivalent, the cost of an external USB computer sound card goes from $10 to $100.  For digital communications, I use a Signalink USB SLUSB6PM isolated sound card.  I have also used a $7 external USB sound card purchased from Amazon with a home-made interface cable.  While the cheap sound card works well, the simplicity and the dial controls of the Signalink, make it a simple to set up, adjust, and utilize.

main component list

• Yaesu FT-891 Transceiver  ($510 w/ rebate Gigaparts)
• SGC SG-239  1.8 - 30 MHz 200W PEP  Smartuner ($174 open box R&L Electronics)
• Signalink USB SLUSB6PM ($97 Gigaparts)
• Grounding Counterpoise via 1-1/2" tinned copper braid w/ RF coupler
• Sta-Lok 5/16” 1x19 SS316 wire backstay insulator  ($225 Offshore Spars) 
• Raspberry Pi 4B 4GB ($55 )

Total Cost: ~$1000