diff --git a/include/tuner_r82xx.h b/include/tuner_r82xx.h
index f6c206a..c9a7a03 100644
--- a/include/tuner_r82xx.h
+++ b/include/tuner_r82xx.h
@@ -116,5 +116,6 @@ int r82xx_init(struct r82xx_priv *priv);
 int r82xx_set_freq(struct r82xx_priv *priv, uint32_t freq);
 int r82xx_set_gain(struct r82xx_priv *priv, int set_manual_gain, int gain);
 int r82xx_set_bandwidth(struct r82xx_priv *priv, int bandwidth,  uint32_t rate);
+int r82xx_toggle_test(struct r82xx_priv *priv, int toggle);
 
 #endif
diff --git a/src/librtlsdr.c b/src/librtlsdr.c
index 5b33310..9162d67 100644
--- a/src/librtlsdr.c
+++ b/src/librtlsdr.c
@@ -1177,6 +1177,16 @@ int rtlsdr_set_agc_mode(rtlsdr_dev_t *dev, int on)
 	if (!dev)
 		return -1;
 
+	/* FOR TESTING ONLY. Uncomment to enable repurposing the RTL AGC button
+	* for switching registers on/off. Uses to test functions of registers easily. */
+
+	/*
+	rtlsdr_set_i2c_repeater(dev, 1);
+	r82xx_toggle_test(&dev->r82xx_p, on);
+	rtlsdr_set_i2c_repeater(dev, 0);
+	return 0;
+	*/
+
 	return rtlsdr_demod_write_reg(dev, 0, 0x19, on ? 0x25 : 0x05, 1);
 }
 
diff --git a/src/tuner_r82xx.c b/src/tuner_r82xx.c
index dbdf4e9..d42241a 100644
--- a/src/tuner_r82xx.c
+++ b/src/tuner_r82xx.c
@@ -1105,6 +1105,25 @@ int r82xx_set_bandwidth(struct r82xx_priv *priv, int bw, uint32_t rate)
 
 	return priv->int_freq;
 }
+
+int r82xx_toggle_test(struct r82xx_priv *priv, int toggle)
+{
+	int rc;
+
+	if (toggle)
+	{
+		fprintf(stderr, "TOGGLE ON \n");
+		rc = r82xx_write_reg_mask(priv, 0x17, 0x08, 0x08); /* open_d notch on */
+	}
+	else
+	{
+		fprintf(stderr, "TOGGLE OFF \n");
+		rc = r82xx_write_reg_mask(priv, 0x17, 0x00, 0x08); /* open_d notch off */
+	}
+
+	return rc;
+}
+
 #undef FILT_HP_BW1
 #undef FILT_HP_BW2