[quote=chic]It would be close to the compass but don't think that has any effect on the GPS [/quote]

Chic. I think the concern is the reverse --- the effect of the GPS on the compass.  See this thread and links therein, starting at comment 3:
https://www.catalina36.org/forum/technical-discussion/wiring-gps-edson-pedestal?t=1777

Chic, the issue - if any - is the effect the electronics would have on the compass, not vice versa, the microphone itself being the most magnetic item of the package. On my Mk II I had the factory pod on the slanted portion of the 1" dia s/s tubing. (See my Below Deck Autopilot article in the Upgrades archive for a photo of the helm.) I have not noticed any difficulty with the compass, although I am not a stickler for an absolutely accurate compass swing.

I just removed the old navpods because of a major electronics upgrade. The new NavPods cost me about $800 bucks, which was a real shock because in my planning I had assumed the old chartplotter pod would work for the new large format Raymarine plotter. I am/was going to put the removed pods on eBay, but we could discuss them; however, I don't think they would work that well on a Mk I due to different diameter of tubing. In any event everything boat-wise for me is on hold until late Jan at the earliest. (The boat's on the back burner because we're headed to Kitz for the holidays. I know you're an old skier and you may be familiar with the Streif, the run down from the Hannenkahm.) 

Prost!
 

I have the angled guard and noticed that when I upgraded from the original C80 to a e127 the compass performed much better.