[Premium-Rx] mixer fets

[Dan Rae]

On 1/6/2013 1:52 AM, engineroom wrote:
> Hi Folks,I need to change mixer fets on a Racal RA1792 it has bsv81 
> type on the circuit drawing but i noticed some posts on here before 
> mentioning the sd215de's being used the receiver picks up only 
> strongish broadcasts stations but passes bite ok i suspect the mixer, 
> it's the later 85830 radio with score.I was wondering if there is a 
> superior fet replacement or should i stick with the drawing type?
> Regards
> Steve in Rugby England
Steve, since you are in the UK, I would expect the European type to be 
easier to source, apart from being probably the best choice anyway.  You 
would need a matched quad.

But there are several other things that could cause your problems. The 
RF amp box has a fuse; check that.  The RF amp transistors can die.  I 
could go on...

I did once fit an SD5000 quad FET to an RA1772 since that was easier for 
me to source at the time, and found a slight and maybe not significant 
improvement in the IP3 number.  It was also fitted to a lot of the later 
US made receivers.

73 - Dan

ac6ao / g3ncr