[Wolf]

Has anyone mounted an Comant marker beacon antenna less than 3 feet from their DME antenna and had good results? My placement will be at about 24 inches and if that will be a problem then I will have to go to plan B.

Jay, RV-7A finishing, UT47

 

[ccrawford]

Not sure why this is in classifieds, but most folks put the DME and Transponder right near the firewall on the bottom of the fuse (on opposite sides, way more than 3') and then the MB goes in a wingtip.

 

[fmarino1976]

Should be fine

The MB and the DME operate in completely different frequency bands that they won't interfere at all at 24 inches appart.

 

[TCONROY]

While the DME and MB operate on very different frequency ranges, that doesn't mean one won't interfere with the other. The DME transmits and receives while the MB only receives. The DME transmiting could cause interference issues with the MB. Are the chances of that happening very great? Probably not. However, most install manuals for certificated aircraft/equipment recommend a minimum of 18" between antennas.
My .02

-EDIT- Didn't see your spacing was 24". That is PLENTY of space between the two.