We broke 2 of them also this year and are looking for replacements.  Tried searching Tessco.com as suggested and could not find them.  Found an older AgTalk thread with a link to Tessco for the antenna and it appears that maybe they don't sell them anymore?  Looked on eBay and they list them, but they ship from either China or HongKong...probably on a slow boat....

Are these 900Mhz or 450Mhz?  They list them for both.

How about the magnetic mount?  The second one that we broke was the coax that went in to the base of the mag mount.