radio

Two things wrong with the Samlex SEC-1235M

The Samlex SEC-1235M is a well priced and performing switchmode power supply. Two things have been bugging me though - the lack of Anderson Powerpole output and the loud fan.

AD5X wrote a comprehensive review of the power supply[1], in which he addressed the fan issue by including a 100 ohm resistor in the fan circuit. I performed the same modification and now the fan is not audible over the ambient noise. A bit of time with a multitool to cut out an opening for a panel mount Powerpole housing and it’s good to go.

Now I can’t really think of anything wrong with the SEC-1235M.

[1] http://www.ad5x.com/images/Presentations/SEC1235M%20Review.pdf

Update - Using APRSdroid with the Kenwood TM-D710 via Bluetooth

Somehow I managed to kill the Bluetooth module I was using (reverse polarity maybe?) and of course couldn’t find another - I’m surprised there isn’t demand for such a module, maybe a project for another time.

Anyway, took a slightly different approach this time. Used a standard HC-05 type module and mounted it in the head. Wired up to some +5v I found and connected to the input side of the RS-232 driver included in the radio head (connected to the 2.5mm socket).

Works well, only downside that comes to mind is that the Bluetooth module is powered on all of the time as the supply to regulator appears to be unswitched.

Location of TX tap to Bluetooth module (TTL levels) Some (attempted) strain reflief with tape Installation complete with module kept in place with double sided tape

Using APRSdroid with the Kenwood TM-D710 via Bluetooth

Quick afternoon project to hook the TM-D710 up to a Galaxy Tab 2 8.0 I recently mounted in the car. APRSdroid can consume and display waypoints using the Kenwood proprietary format outputted by the radio, all that was needed was to get the data to the tablet.

For this, a small Bluetooth - serial adaptor was mounted in a project box. It’s a variation of the popular “HC-05” module as was labelled “BTM-05”. It includes both a MAX232 and a voltage regulator, so nothing further was required for power and data.

Mounted in the project box with connectors for quick removal if required.

Output from radio displayed in APRSdroid.