[Elecraft] Macro to turn an external amplifier on and off

[Vic K2VCO]

I wanted to create a K3 macro to turn an external amplifier on and off. It turns out that 
with firmware 3.60, which is now in field test and will shortly be in beta, it's possible. 
The technique probably has other applications, like controlling filters or preamps, etc.

A new MP command allows you to set the DIGOUT1 control line (pin 11 of the K3 accessory 
connector) to go to ground. This line is per-band and per antenna. This line can sink only 
15 ma, so I used a simple PNP transistor switch to operate a relay which enables my amplifier.

My AMP IN macro sets the power to 65 watts and activates (grounds) DIGOUT1 when its 
associated button is pushed. There's a companion AMP OUT macro which increases power to 
100 watts and ungrounds DIGOUT1.

Since DIGOUT1 is per-band, it's necessary to set CONFIG:PWR SET to PER BAND also. Then you 
can set the amplifier to be on for 20 meters, say, but off for 40. Changing bands will 
automatically turn the amp on or off and set the proper power level.

Here are the macros:

AMP IN:  MN019;MP001;MN255;PC065;
AMP OUT: MN019;MP000;MN255;PC110;

The MN019 command selects the DIGOUT1 menu option, the MP command turns the line on or off 
on the band that you are on, and the PC command sets the power level. My SB-1000 likes 
about 65 watts, so that's what I select when the amp is on.

Wayne has made the MP command work for DIGOUT1 in 3.60, so you'll need at least that version.

-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco