[R-390] Our website's Reference page 'Web Pages' section update

[Larry H]

At the bottom of our website's 'Reference' page are some links to other
websites in its 'Web Pages' section.  I removed the one to
Miltronics because it does not exist any more.  I added 3 new ones
that have R-390 info in them: Navy-Radio, Radio Boulevard, and Jammin Power.

If there are others that make sense to add there, let me know.

Regards, Larry