the Mike Mercury Ham Radio Page

Yaesu FTM-350 / Yaesu FT-90R / THD-72A / DR-535 / IC-7100 / Main



APRS Setup Page

Vehicle Installation Page

FTM-400 Yaesu notes:


The external speaker jack is a STEREO 3.5mm jack. There are two audio amplifiers feeding that jack, phased into one mono output. This mono output is of the "balanced" type... neigher side of an external speaker voicecoil goes to DC ground.

If you connect an external speaker that is not the factory offering - purchase a stereo 3.5mm plug and connect the "+" and "-" leads from your external speaker to the stereo plugs "tip" and "ring" locations. NOTHING is connected to the ground terminal of the plug. DO NOT USE A MONO PLUG for a single speaker setup when directly connecting an external speaker into the radios external speaker jack - as it will short one of the audio amplifiers output to ground and could cause the radio to overheat.


FYI; the optional factory external speaker (MLS-200-M10) is the same way... with a stereo plug on the end of the cable; wired to use the tip & ring only (the ground connection goes to a braided shield that is wrapped around the entire cable.... and is connected only at one end).


Hand Microphone
The supplied DTMF mic has a sensitive PTT switch. I took out the two screws and opened the case (clamshell style) and filed down a little bit of plastic from the plastic PTT levers "tang" that makes contact with the actual switch. It didn't require hardly any filing to make a difference; now requiring 50% travel before the TX is activated.

GPS Performance
The internal GPS receiver is quite sensitive. I get a GPS lock even though the control head is installed in a location where it does not see the sky directly.

For hints on setting up your FTM-400 to transmit your location, see this page:APRS page

RT Systems Programing Software
Makes this complicated & feature rich radio a lot easier to manage; I strongly suggest purchasing it.

After Yaesu updated the radios firmware to 2.0... it can now use the SCU-20 USB cable to program the channel and settings info. The SCU-20 is the cable Yaesu included with the radio; and was originally intened to be used for firmware updates only. But after upgrading the radio to Yaesu firmware 2.0 ... you can use either the SCU-20 cable for channel & settings upload/download... or the original memory card method.

Yaesu themselves has recently written their own programming software, which is a free download from their webpage. With radio firmware 2.0, you now have choice of:
* programming software (RT or Yaesu offering)
* transfer methods (USB using Yaesus provided cable, or the original memory card method. Both these methods work on the RT software and Yaesus new offering).

* you need firmware 2.0 in order to use the new (free) Yaesu ADMS program.

* you need firmware 2.0 in order to use the SCU-20 USB cable for programming transfer.

APRS Setup Page

Vehicle Installation Page 

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