[R-390] receiver sensitivity testing

[rbethman]

Amen!

My HP-3336B is still in calibration as so tagged by the USAF.

Frequency is accurate +/- 10Kc.

While its output is 75 ohm, I can either take 50 ohm off the attenuator 
internally, or go nuts and spend an additional $150 to obtain the HP 
Option Board to add it for the external WECO jacks.

Have the requisite silver plated copper expanded mesh to close the whole 
mess in, or could get copper screen to do same.

Bob - N0DGN

On 3/1/2012 12:44 PM, Tisha Hayes wrote:
> If you are looking to test down in the -130's and -140's you would
> really need to do it in a Faraday cage with a lab-grade signal
> generator, precision RF connections and attenuators. There are just
> too many variables and outside sources of noise to make any numbers
> you get down there to be meaningful.
>
> Everything would need to be buttoned up tight, every cover in place,
> all the screws and modules completely in place, the best tube
> line-up's in the right positions and pulling your monitored signal off
> of the diode load connection to minimize distortion from the audio
> deck.
>
> One thing the R-390A does not suffer from is a lack of sensitivity. If
> anything was to be done to enhance certain receiver characteristics it
> might be to improve the selectivity and IP3 points. Roofing filters,
> changes in the way the IF's are staggered tuned, etc... could all help
> you with selectivity but at the trade off of any high fidelity
> performance with the 16 khz filter position.
>
>