[Moon-net] Mirage D1010 Amp advice

[Bert, VE2ZAZ]

Hello everyone,

I own a Mirage D1010 UHF amplifier, the white and brown face version. It looks like I transmitted without antenna (!!!) for too long. The unit now puts out only around 40W. It looks like one of the two MRF648 transistors is dead. Only one warms up when I key down. I have the expertise and the tools to replace it. But should I waste money and time?

The P.A. configuration seems to be a simple parallel splitter and combiner between the two transistors, not a push-pull design. But does it still call for a matched-pair? What is the likelyhood of blowing up considering that the transistors would be from different batches. The bias current is set to 200mA and is assumed to split equally between the two transistors. How bad could it be if they are not a matched pair?

So is it woth spending ~$40 on one  transistor or $80 on a pair, or much more on a matched pair? Or should I simply buy a new amp? Some past experience with such situation is sollicited.

Thanks and 73,

Bert, VE2ZAZ
FN25
http://ve2zaz.net


      __________________________________________________________________
Yahoo! Canada Toolbar: Search from anywhere on the web, and bookmark your favourite sites. Download it now at
http://ca.toolbar.yahoo.com.