Difference between revisions of "Scanner Crystals"

Revision as of 16:17, 6 January 2016

77 means it was made for a Radio Shack Pro-77 and uses a 10.7 IF.

@@ Line 1: / Line 1: @@
-==Crystal Formulas==
+==Bearcat Crystal Formulas==
-Bearcat scanners use a 10.8Mhz Intermediate Frequency.
-The formula is Channel Frequency minus 10.8Mhz divided by 3.
-Radio Shack & Regency scanners use a 10.7Mhz Intermediate Frequency.
+===Bearcat Low-band===
-The formula is Channel Frequency minus 10.7Mhz divided by 3.
+*Third Overtone
+*Receive frequency + 10.8 MHz = crystal frequency
+*HC25/u holder
+===Bearcat High-band===
+*Third Overtone
+*Receive frequency - 10.8 MHz / 3 = crystal frequency
+*HC25/u holder
+===Bearcat UHF-band===
+*Third Overtone
+*Channel frequency - 10.8 MHz / 9 = crystal frequency
+*HC25/u holder
+==Regency/Radio Shack (Realistic) Crystal Formulas==
+===Regency & Radio Shack (10.7 MHz IF) Low Band===
+*Third overtone
+*Receive frequency + 10.7 MHz = crystal frequency
+*Series resonance - 450Hz
+*HC25/u holder
+===Regency & Radio Shack (10.7 MHz IF) High Band===
+*Third overtone
+*Receive frequency - 10.7 MHz / 3 = crystal frequency
+*Series resonance - 450Hz
+*HC25/u holder
+===Regency UHF-band===
+*Third Overtone
+*Receive frequency - 10.7 MHz / 9 = crystal frequency
+*Load capacitance 18pf
+*HC25/u holder
+===Radio Shack (Realistic) UHF===
+*Triple conversion
+*Receive frequency - 44 MHz / 9  = crystal frequency
 ==Crystal Markings==