From 8426cbe3f055bdd118cbd6949113bf2c35596be5 Mon Sep 17 00:00:00 2001
From: rtlsdrblog <admin@rtl-sdr.com>
Date: Wed, 23 Aug 2023 22:23:58 +1200
Subject: [PATCH] add offset tuning bias tee hack

---
 src/librtlsdr.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/librtlsdr.c b/src/librtlsdr.c
index ee13556..d0a16fc 100644
--- a/src/librtlsdr.c
+++ b/src/librtlsdr.c
@@ -1242,8 +1242,15 @@ int rtlsdr_set_offset_tuning(rtlsdr_dev_t *dev, int on)
 		return -1;
 
 	if ((dev->tuner_type == RTLSDR_TUNER_R820T) ||
-	    (dev->tuner_type == RTLSDR_TUNER_R828D))
+	    (dev->tuner_type == RTLSDR_TUNER_R828D)) {
+		/* RTL-SDR-BLOG Hack, enables us to turn on the bias tee by
+		* clicking on "offset tuning" in software that doesn't have
+		* specified bias tee support. Offset tuning is not used for
+		*R820T devices so it is no problem.
+		*/
+		rtlsdr_set_gpio(dev, 0, on);
 		return -2;
+	}
 
 	if (dev->direct_sampling)
 		return -3;