[Premium-Rx] Premium RX Strong Signal Performance

[John Reed]

I recently moved to a new location and discovered that there is a meduimwave broadcast station on 1450 KHz about 1/2 mile from my location with 5000 watts of power.  This has given me the opportunity to test various receivers in the strong field of this station.  For an antenna I'm using Dallas Lankford's Ultralinear whip with push-pull second stage.  There is a weak station on 1460 KHz and the test is based on how well this station can be heard.

Here are some results, in order of best to worst:

Racal RA6793A - good readability.  I used USB and manual AGC.  RF gain was turned down to give the best signal.

Racal RA6772E - essentially the same performance as the RA6793A.

WJ DMS-105R - more splatter.  I used 20 dB of input attenuation and the gain controls for best signal.  This receiver is single conversion so there is no roofing filter, also analog tuned so phase noise is minimal.  Still not as good as the Racals.

NRD-525 - more splatter and noise than the above receivers.  This is not a stock 525.  It has the ESKA roofing filter and PLAM board with post IF filters.

Harris RF-550 - Very noisy and splatter was bad.  Just pieces of the received signal could be made out.  USB was used, manual gain and RF and audio gain were adjusted for best reception.

Harris RF-590 - about the same as the 550, but not as much signal made it through.

I am surprised at the wide range in performance between these receivers.  The published specs don't indicate to me that much of a difference should exist.  I'm curious as to what specs would be most important in quantifying this test?

John Reed


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