[Premium-Rx] Racal RF preamp

[Carcia, Frank A. HS]

    I would think adding an amplifier will cause the second mixer to
overload
    at a lower level. I found the Racal first mixer is good up to minus 30
dBM
    before third order spurs come out of the noise floor.       fc

-----Original Message-----
From: GandalfG8 at aol.com [mailto:GandalfG8 at aol.com]
Sent: Sunday, February 16, 2003 3:57 PM
To: 103360.2133 at compuserve.com
Cc: premium-rx at ml.skirrow.org
Subject: Re: [Premium-Rx] Racal RF preamp


Hi Tom 
You raise some interesting issues on this one. 
I found an online reference a while ago to the "rare" 6790 RF amp. 
The external and internal photos, and schematic, looked to be identical to
the amp fitted to the 1792. 
I have a spare amp and was planning to fit that to my 6790/GM but was
advised that the 6790 overloads with the amp fitted so I left well alone. 
Although fitted as standard to the 1792 there are internal links which will
bypass the amp but I've not heard of anyone doing that. 
Certainly my 6790 seems just as sensitive without the amp as the 1792 does
with it but I must admit that I haven't done any measurements to confirm
that. 
I don't know that the 1792 front end was dodgy but do wonder, despite other
similarities, if the gain distribution in these two receivers is different. 
regards 
Nigel Clarke 
G8PZR 



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