1. GPS is a receive only service, two units should not ever interfere
with one another even if very close.
2. Yes, some Military jamming is done on GPS signals as a part of
Electronic Warfare, flying near MOAs could give problems, but NOTAMs
should alert you of it.
3. I believe as long as the pressure altitute is running and the
outage is a reasonable length, OLC and Contest rules allow you to
ignore the time of no GPS signal.

Since I'm just a normal IS & RF background type, is the above a
correct set of observations and responses? Dan_the_wri?

4. I've had several outages in the White Mts of Ca, but usually due to
poor antenna orientation on a G76s unit that wants to lay flat to best
receive signals.

5. Does anyone know for sure how long an outage OLC allows?

Thanks,

Wayne