[RTTY] Mark V power level

[DESLOOVERE DIRK]

Dear Jim

I am running a markV since june 2002.
I have been running several  + 24 hours contests.   The cq ww and wpx  rtty in LP  is allowing 150 W level and then the  cooling system is at max.  but the radio does handle it for hours and hours.

e.g. in the last cq ww rtty  I have been operating 41 hours at this powerlevel : running and S & P .

Even at 50 w the cooling fins becomes warm and the fans start to roll  at 40°C.

It has also do with the idling current of the finals the finals draw  current even without a single watt rf output.

e;g.   in class A  the finals are drawing 10 A  at idle   thats  300 W dissipation wtihout any watt rf output !!!  Then the heat sink becomes hot without output. 

The mark V handles  100 W at 100 % duty cycle , 200 W at 50 % duty cylcle   (manual specifications)
it is a solid performer  no doubt !!      The finals are  two BLF147   with each 220 W dissipation , rated at 150 W output each,  so the Yeasu engineering dept. has well built the finals with good IMD and long term use in mind. 
The power supply is rated a 450 W.

Only Yeasu has not found a solution for quiting the fan in the 1000 series.

Before this mark V  I used a ts850 s   a solid performer  in rtty.  Only my power supply could not handle the heavy duty rtty, so I added a external cooling fan on the ps. 




DIRK
ON4ADZ