Difference between revisions of "Forty-9er"

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Latest revision as of 10:27, 10 December 2016

The forty-9er is an improved design over the Pixie2. It has two crystals, one for the rx and one for the tx frequency.

RX power consumption is around 23mA @ 12V

Output power is around 2 to 3 Watts.

Forty-9er-topview.jpg


Forty-9er pcb top.jpg


Forty-9er pcb bottom.jpg


Forty-9er Schematic


Description of the original Norcal Forty 9er File:49erOrigMnl.pdf


The Final Power Amplifier that is shipped with this kit is the NEC D882 NPN Transistor.

datasheet: File:NEC-2SD882-datasheet.pdf

Apparently, the datasheet lists this part as suitable for a 3W audio amplifier but it has an Ft of 90MHz.

An initial check revealed that the power output was only 600mW so I decided to replace it with a BD139 which has an Ft of 190MHz. It also has the same footprint and pinout so it is a drop-in replacement for the D882.

BD139.jpg


After fitting this transistor the power output was about 1W.