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Low voltage output.
¿ªÔÆÌåÓýYes, I said low voltage. In order to use the ATAS ?antenna the rig should put out 8 volts. Mine only puts out 4 volts. Any ideas? wd9ghk |
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Where are you measuring this voltage? Depends which way you are driving the antenna, Voltages the radio applies to the ATAS antenna are 8.36 volts to move down, and 9.76 volts to move up. There is an interface board inside the base which senses this voltage from the radio and determines the direction of the motor. It all relies on an SWR sensor to deteine when the motor stops <2:1. If its the first time you have used it with the radio it will go through initialisation stage which drives it to one end of its travel and sits there with the motor turning but there is a slipping clutch to stop damage to the gears. After the initialisation it will drive the opposite direction and should stop when the SWR is <2:1 If it drives to the other end the SWR is too high and further investigation is required, poor earth being a main factor. Otherwise it could be a poor connection on the base or the coax plugs.? 73's On 7 Feb 2022 15:54, Bruce <wd9ghk@...> wrote:
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VSWR Adjustment 1. Connect a 100-Ohm dummy load to the HF/50 MHz antenna jack. 2. Tune the transceiver to the 14 MHz band in the CW mode, and set the output power to 10 Watts. 3. Select menu item ¡°69: SWR2.¡± Key the transceiver and press the [A] key to set this parameter. 4. Connect a 150-Ohm dummy load to the HF/50 MHz antenna jack, and set the output power to 10 Watts. 5. Select menu item ¡°70: SWR3¡±. Key the transceiver and press the [A] key to set this parameter. ATAS control voltage confirmation 1. Connect the DC voltmeter to the HF/50 MHz antenna jack. 2. Select menu item ¡°71: ATAS.¡± 3. Press the [A] key, and confirm that the voltage is 9.0 to 10.1 Volts. 4. Press the [B] key, and confirm that the voltage is 7.5 to 8.5 Volts. 5. Press the [C] key, and confirm that the voltage is more than 10.5 Volts.
You might check the protection diode on the tap from the antenna jack. The ANCV and ANNG are from the CPU (I think I did not trace them back, but probably a good guess). Q3004, 3006, 3013, 3029, and 3031 are involved with sending the correct voltage through L3074 and L3075 as the ANT signal. |
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Hi Bruce. When you say you measured the voltage at the connector, can you clarify which connector? I also assume the radio is working perfectly otherwise and when you select TUNE on the menu the antenna does not move but the display stays bright. In other words the 12v supply to the radio is capable of supplying the additional current to drive the antenna? Have you tried connecting the power supply direct to the radio with short leads and see if the ATAS 120 works correctly then? What I am suggesting is there could be a poor connection in the supply on a fuse holder which is not allowing sufficient power to supply the radio and drive the antenna, as it does transmit low power to detect the SWR of the antenna during tuning and stops at minimum <2:1 swr. As you have tried two different antennas on a separate power supply, can you confirm both the antennas behave in a similar manner driving up at approx 9.8v and driving down at 8.4v (assuming the Output of the power supply is variable). I have an FT857 which is now 14 years old, I have overhauled the ATAS 120 so both work perfectly. Whether you have damaged any components internally has yet to be determined. 73 Bob On 10 Feb 2022 18:08, Bruce <wd9ghk@...> wrote: Robert, |
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