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Reviews For: AM-COM ATAS-100 Controller

Category: Antennas: HF Mobile & Accessories

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Review Summary For : AM-COM ATAS-100 Controller
Reviews: 1MSRP:
Description:
Simple switch controller for Yaesu ATAS-100 antenna
Product is not in production
More Info: http://
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
0011
WB0KWJ Rating: 2020-11-23
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 an unreasonable price. The unit I bought 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. The component lead was simply pressed into the hole of the connector. No real RF or DC connection existed. It is possible this particular unit never worked.

Construction is point-to-point, with longer lead lengths that is advisable in RF circuits. 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. Something like .05 uf (or even .1 uf) at a higher voltage would have been more suitable to provide a low impedance RF path at 40 meters. It almost seems as if a component selection error was made during construction. The blocking choke seems adequate.

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 (approximately 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. The stall current of the ATAS-100 is about 0.6 amp, meaning that the unsunk 8 volt/1 amp regulator could overheat 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.