Drake R4 Receiver

Drake R4 Receiver Performance Test

Drake R4


Band	MDS	Blocking	Two-tone D.R.
		(20 kHz)	(20 kHz)

80 meters	-139 dBm	111 dB	81 dB
40 meters	-139 dBm	112 dB	81 dB
20 meters	-140 dBm	113 dB	82 dB

AM Audio S/N: 47 dB

AM Audio Frequency Response:

100 Hz

200 Hz

400 Hz

600 Hz

800 Hz

1 kHz

2 kHz

3 kHz

4 kHz

5 kHz

6 kHz

-28 dB

-20 dB

-6 dB

-2 dB

0 dB

-3 dB

-16 dB

-27 dB

-32 dB

-42 dB

AM Audio Distortion:



Mod%	100 Hz	200 Hz	400 Hz	600 Hz	800 Hz	1 kHz	2 kHz

30%	-	-	3.2%	1.8%	1.3%	1.1%	1.6%
50%	-	-	3.2%	1.8%	1.3%	1.2%	2.2%
70%	-	-	3.2	2.0%	1.4	1.4%	2.8%
90%	-	-	4.5%	2.5%	2.0%	2.0%	3.2%
100%	-	-	8.9%	4.5%	3.2%	2.8%	3.2%

Notes: AM frequency response was fairly restricted due to the 4.8 kHz maximum i-f bandwidth. AM distortion numbers show the somewhat typical increase at lower audio frequencies - most often caused by the low audio frequencies riding on the AGC line. The audio response rolls off rather quickly on the low end. A frequency response test was run on just the audio output stage which confirmed the tiny audio output transformer to be responsible for the poor low frequency audio performance.