[Premium-Rx] RA6793A Sensitivity?

[fintronicsusa]

Howdy folks.... I just acquired a Racal RA6793A with the optional pre-amp.I've yet to do any actual measurements but it seems like the sensitivity is very low (full size outdoor wire antenna).
Even on what are normally strong local broadcast stations, the RF meter won't even reach half scale. Approximately what level should i see on the Rf meter vs a given input signal level?. I'd like to try some tests with a sig gen. I'm wondering if the pre-amp might be defective or possibly something else in the front end.
Thanks.
Glenn KJ2R