TM 1-1520-238-10 3-18.8 Change 3 c. HaveQuick (HQ) Operation. The HQ mode of op- eration provides a jam resistant capability by means of a frequency hopping technique that changes frequency many times per second. Automatic frequency changing in an apparently random manner provides the jam resist- ance of the radio. The HQ radios permit communication in radio-jamming environments. Three elements are re- quired for uninterrupted, successful communication. Ra- dios must use the word-of-day (WOD), be time-synchro- nized with each other with a time-of-day (TOD), and share a common net. (1) Word Of Day (WOD). The WOD programs the frequency hopping rate and frequency hopping pattern. The radio cannot function in the anti– jamming mode without a valid WOD. The WOD does not take up preset memory, but the WOD memory is accessed through preset locations 20 through 15. The seventh location, accessed through channel 14, stores the Day of the Month information. This date code works in conjunction with the TOD and specifies the day a specific WOD is to be utilized when Multiple Word of Day (MWOD) are entered. At midnight (GMT) transi- tions, the radio automatically generates a new frequency hopping pattern based on the new days WOD. Up to six WODs may be entered at one time, allowing for multiple day use of the ra- dio set without installing another WOD. (2) Time Of Day (TOD). Time synchronization is necessary for communicating in the anti–jam- ming mode to allow frequency hopping at the same instant in time. TOD information is ob- tained from the UHF radios that have been mod- ified to receive the Universal Time Coordinated (UTC) signal. UTC is a worldwide standard and is available from a variety of sources, such as the Command Post, Global Positioning System (GPS), and AWACS. A valid TOD signal will be heard as a two–beat frequency tone. Once all radios are operating on UTC, uninterrupted voice communications are insured. The radio automatically accepts the first TOD signal after power up. The first reception must occur in the normal mode. Updates of the TOD may be per- formed in the anti–jamming or normal mode. Subsequent TOD transmissions are ignored un- less the operator enables the radio to receive a new TOD. If communications during anti–jam- ming operations become slightly garbled it is an indication of drift in TOD synchronization... d. HaveQuick II Command Codes. There are four separate Command Code functions associated with load- ing the HaveQuick II radio. The operator enters a six digit command code into preset 20 to begin the unique initiali- zation procedure. The Command Codes, their function and Frequency/Status indication are shown in table 3-7. Table 3-7. HAVEQUICK II Command Codes Command Code Function Frequency/ Status Indication 220.000 Verify/Operate VER/OP 220.025 MWOD Load M–LOAD 220.050 MWOD Erase ERASE 220.075 FMT.CHG Fre- quency FMT.CHG 3.7B.4 Manual Single Word Of Day (SWOD) Loading. NOTE The below procedures step through enter- ing the Training/Maintenance WOD for per- forming checks and maintenance. An actual WOD may be entered as a substitute in the below steps. 1. Function Selector switch – PRESET. 2. CHAN switch – Set to Channel 20. 3. Frequency switches – Set to 220.000 MHz. 4. LOAD button – Lift preset frequency label cover and push LOAD button. To check that radio is in the VER/OP mode, press the STATUS button and the frequency/status LCD should display VER/OP for five seconds. 5. Frequency switches – Set to the first WOD seg- ment frequency (300.050) of the Training/Main- tenance WOD listed in table 3-8. Table 3-8. Training/Maintenance WOD and Common Net Preset Channel WOD Segment Common Net 20 300.050 300.000 19 376.000 300.000 18 359.100 300.000 17 314.300 300.000 16 297.600 300.000 15 287.400 300.000