Differences

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--- vsg25_mod [2024/05/22 09:53] – admin
+++ vsg25_mod [2024/05/22 16:46] (current) – admin
@@ Line 1: / Line 1: @@
 ====== Signal Hound VSG25 - Modification for better frequency stability ======
 {{:projects:signalhound_vsg25:20240513-121755.jpg?direct|Signal Hound VSG25 - Disassembled}}
-{{:projects:signalhound_vsg25:20240513-121921.jpg|Signal Hound VSG25 - Modification Closeup}}
+{{:projects:signalhound_vsg25:20240513-121921.jpg?direct|Signal Hound VSG25 - Modification Closeup}}
 {{:projects:signalhound_vsg25:20240513-122256.png?direct|Signal Hound VSG25 - Mod Schematic}}
 {{:projects:signalhound_vsg25:20240513-124435.png?direct|Signal Hound VSG25 - Mod Layout}}
+===== Tests =====
+  * Tests run at 162MHz nominal with 0dBm output power. Ambient Temp: 24C Deg
+  * VCTCXO Freq is measured by Racal 2202R Universal Counter/Timer (it has a rubidium reference so it is reliable!)
+  * Frequency drifting before modifications were over 500Hz
+  * Frequency drifting after VCTCXO modification was 19Hz
+    * Initial freq: 162.000006MHz
+    * After 2.5hrs: 162.000025MHz and kept drifting
+  * Frequency drifting after VCTCXO and heatsink added was 10Hz and stabilized relatively quickly
+    * Initial freq: 161.999983MHz
+    * After an hour frequency stabilised on 161.999993MHz