norm2 wrote:

<<

I was all set to proceed with no vacuum until I discovered there is no
electric powered DG with a heading bug output for my S-Tec autopilot

(other

than very expensive HSI).  But, not for this, I would eliminate the engine
driven vacuum system as a 'no-gainer'.

Al>>

Use the GPS Smart Coupler from http://www.porcine.com/.  Lets you follow a
programmed course or act as a heading bug from the GPS output signal.  This
is built into the Navaid unit that I have on order.  Looks like a slick way
of getting a heading bug as well as a wing leveler autopilot. The switch
lets you select heading bug or route tracking, and by bumping the switch you
can adjust the heading 1 degree at a time.  Seems to be well thought out.  I
know several indivduals that are flying them, and they sem to be pleased
with the system.

A lot simpler than a vacuum system.  When you are counting on an electrical
system for fuel injection pumps and ignition systems, I don't see what you
gain from having a vacuum system.  The price is better on DGs and Artificial
horizons, but you pay for ti with complexity and maintenance.  I am not sure
why you would need a DG (except it is required for IFR) given how the GPS
works.

If you plan on going anywhere it is very wise to have an attitude gyro or
artificial horizon in there. You never know when you might really need it.
It has saved my butt more than once.

Paul Lamar

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