Ten Tec Titan ll and 4CX1600B tube

[wa2mzx2]

I have owned a Titan ll for less than 2 years with no problems whatsoever. Recently I found need to sell some radio gear due to low funds and when I listed the Titan I received alot of feedback about no availability of the Svetlana 4CX1600 tube. I started researching this info on the net and even put a call in to Ten Tec. It seems there are no '1600's to be found and the only other tube that will work in this amp, GU91B, is hard to find and very expensive!!!!! I don't know about any of you other Titan ll owners but I hate to think that as soon as this tube fails I will have $3000. worth of parts sitting here! I started checking into having someone re-do the amp to use a pair of 3CX800's. Has anyone else checked into this alternative or done anything like this? Any help would be appreciated. If and when I find something out I will post it here or share it with anyone who asks. Thanks es 73, Ray WA2MZX