There are lots of people here into Grundig and the other popular German sets; and more than a few who think the 210 is the best SW portable ever built.
There might be a few Zenith/TO fans who'll disagree though...
Not sure which one you have, but it's a complicated mutha, regardless. I have no idea of the bulbs (the omni-present Tom Bavis may have a SAMS Photofact) but just a bit of surfing turned up this excellent write-up:
http://www.radiointel.com/nr-satellit6001.htm
And the author's listed email:
jay@radiointel.com
Enjoy the Grundig, and let us know what you find out-