Title: OCR Document
Author: Readiris
Last saved by: Larry Labb
Company: I.R.I.S.

CRYSTALS

70-835

The transceiver has 7 channels, transmit and receive, or a total of 14 crystal locations. The channel selector switch selects one transmit and one receive ~el in each of its 7 positions. Additional crystals are available from Midland Dealers. Should you desire to order additional crystals from a specialty crystal manufacturer, the following correlation data is provided.

CRYSTAL SPECIFICATIONS

NOTE: CRYSTAL PARAMETERS ARE SPECIFIED AT 55 DEG C OPERATING TEMPERATURE

TRANSMITTER CRYSTAL

Holder type
Oscillation mode 
Electrostatic Capacitance
                            Load capacitance
Drive level
Equivalent resistance 
Frequency tolerance 
Crystal frequency 
Frequency stability 
Aging

HC-42/U
Fundamental
Less than 7 pF
27 pF
1 mW
Less than 15 ohms
+10 PPM at 55 Deg C
Desired operating frequency/9 
+4.5 PPM (+40 to +70 Deg C) 
Less than ~3 PPM per year

.

RECEIVER CRYSTAL

Holder type
Oscillation mode
 Electrostatic capacitance 
Drive level
Load capacitance 
Equivalent resistance 
Frequency tolerance 
Frequency stability 
Aging
Crystal frequency

HC-42/U
5th overtone
Less than 7 pF
1 mW
Series Resonance
45 ohms max
+ -10 PPM at 55 Deg C
+~4.5 PPM (+40 to +70 Deg C) 
Less than ~3 PPM per year
= f + d PPM * (f)
(Calculate f and d as below)

f = (desired operating frequency - 21.4 MHz)/2

7

-R