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Reviews Categories | Antennas: HF Mobile & Accessories | AM-COM ATAS-100 Controller Help


Reviews Summary for AM-COM ATAS-100 Controller
AM-COM ATAS-100 Controller Reviews: 1 Average rating: 1.0/5 MSRP: $(missing—add MSRP)
Description: Simple switch controller for Yaesu ATAS-100 antenna
Product is not in production.
More info: http://
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WB0KWJ Rating: 1/5 Jan 2, 2017 07:43 Send this review to a friend
Very poorly constructed  Time owned: 6 to 12 months
This device is designed to directly control a Yaesu ATAS-100 antenna by putting the required DC control voltages on the coaxial cable. The ATAS-100 was designed to work with various Yaesu radios, such as the FT-100 and FT-857. Different voltage ranges extend or retract the antenna, eliminating the need for a ground isolation as would be required if positive and negative voltage were used to run the antenna drive motor in different directions.

My unit cost me $1 at a hamfest, sold by a ham who seemed happy to be rid of it. I believe they cost about $80 originally--not unreasonable. It was in pristine condition, apparently never used much. A brief inspection revealed why. The solder connection to the inner conductor of one of the SO-239/UHF coaxial connectors had never been properly made, leaving the component leads simply pressed into the hole. No real RF or DC connection existed. It is possible the device never worked at all.

Construction is not even up to MFJ standards. The components are not on a circuit board, but wired using what some called "ugly construction." It is obvious that the makers of the device were unconvinced of the value of keeping component leads short in RF circuits. It does not appear that any leads were trimmed at all. Some of the insulated DC leads touched the RF leads, inviting arcing and shorts via wear-through.

The selection of component values is also questionable. The feed-through capacitor in the coax biasing circuit is .0068 uf at about 100 volts, when something like .05 uf or even .1 uf, at a higher voltage would have been more suitable to provide a very low impedance in the RF path at 40 meters. It almost seems as if a component selection error had been made during construction. The blocking choke seems adequate, although I did not test to see if it had any unwelcome resonances at operating frequencies, as sometimes occurs.

A single voltage regulator with no heat sink, soldered directly to a toggle switch, provides the 8 volts needed to retract the antenna. The extension voltage (~12 volts) is simply fed through from the power supply. There are no fuses in the device. The antenna requires only about 180 ma to operate normally, but that does not mean the voltage regulator should be left hanging in the air, as it literally is. The stall current of the ATAS-100 is about 0.6 amp, meaning that the unsunk 8 volt/1 amp regulator is going to overheat quickly at the end of the antenna travel. It is up to the operator to be careful. Additionally, the 8.1 volts measured at the coaxial cable output is just under the maximum retraction voltage specified for the ATAS-100. A six-volt regulator would have been more suitable.

In conclusion, the AM-COM ATAS-100 controller is potentially a very useful device for those with an ATAS-100 (or ATAS-120) antenna but no corresponding Yaesu radio. However, the usefulness of the AM-COM device is severely undermined by the very low quality construction and iffy component selection. If one is found used or at a hamfest, an hour or two of work could put it in good working order.

 


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