ALIGNMENT OF THE TEN TEC TRITON IV TIMEBASE SERIES

Unfortunately, the Omni Series B front-panel selectivity ' control does not allow the use of the 500-Hz cw crystal filter without also utilizing the internal audio filter. _ Standard 2125-Hz Hark and 2295-Hz Space RTTY high' tones used to operate most common radioteletype modems (terminal units) can be received in this manner. Operation in this manner will provide excellent lsb RTTY operation on the 14- through 28-MHz bands - provided the cw audio filtering centered on 750 Hz is not used. the carrier oscillator frequency is such thai the audio output passband will be about 1900- to 2400-Hz. Luckily, when the 5Q0-Hz crystal is in use on reverse sideband mode (SB-R). Remove H24, a 680-k.ohm resistor, and use low leakage tantalum capacitors to lessen the load on the age amplifier and detector to reduce the attack time.

The 'slow' capacitor is soldered to the board on the positive end and to the switch for a ground.

Choose the capacitor values according to your taste. The circuit is changed as shown to de-creasen the attack time thereby eliminating the pops.' The capacitor values shown provide age decay times that: were half (on fast) and double (on slow) the time constant originally provided. I broke the connection between the switch and the Audio/Sidetone board (#80447) and rewired the QSK switch to the i-fВ»-agc board (#80448) to give fast and slow age choices. I used the Fast/Slow QSK switch for this' purpose since I always used fast QSK. A change of component values and the addition of a switch will cure both problems. Or in a net with strong and weak signals, the slow decay of the age prevents hearing weak signals for several seconds after a strong signal has ceased transmitting. When a strong signal appears, the slow attack of the age causes a loud pop, particularly on cw with headsets. I was disappointed with the age system response for two reasons. A linear 10-kij sub-miniature bushing mounted control with a long shaft and a spst rotary switch is recommended. The zero-beat push switch may be unmounted, insulated and taped inside the radio to allow mounting the new squelch control. An operative squelch system requires only a control and switch.

ALIGNMENT OF THE TEN TEC TRITON IV TIMEBASE MANUALS

The later manuals do not show the schematics to these parts though they are installed.

In all Omnis, except the latest Omni-Cs, the components for the squelch circuit are on the audio board (#8044?) and the i-f/agc board (#80448). Each modification is independent and need not be done with another.

ALIGNMENT OF THE TEN TEC TRITON IV TIMEBASE FULL

The modifications provide squelch, selectable receiver age decay times, 500-Hz crystal filtering for RTTY reception, accurate frequency spotting during cw operation, full break-in cw with a companion kW aniplifiers automatic frequency control afc) to eliminate VFO drift, power supply over voltage protection and QRP operation with ale control. The improvements are 'removable' in that no holes are drilled and irreversible changes are used.

These changes are applicable to moat models of the Omni and some of the Triton 540s and 544s. Being an incurable experimenter, I have made numerous modifications to my Ten-Tec Omni-D Series 6.

Alignment of the ten tec triton iv timebase