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CX-AUTO Switch

CX-AUTO coaxial switch

The CX-AUTO was designed to satisfy the many requests from AT-AUTO owners for additional coaxial outputs. It does that quite well and more! The CX-AUTO is a QRO-capable RF coaxial antenna switch that integrates seamlessly and automatically with the AT-AUTO and expands the AT-AUTO's singular coaxial output to 8 coaxial outputs.

The CX-AUTO operates from 160-6M and will conservatively handle 1500 W CW key-down. Competitors offer multi-port, remotely controlled antenna switches but none of them are capable of automatic integration with the AT-AUTO. Once the CX-AUTO is connected to the AT-AUTO, the user's choice of any one-of-eight coaxial outputs may be automatically selected whenever the user changes bands - all done autonomously - without need for operator intervention.

The AT-AUTO / CX-AUTO combination provides the user with a fully-autonomous antenna selection capability regardless of the make/model of radio used with the AT-AUTO (requires AT-AUTO firmware version 2.13 or later). Automatic antenna selection works with Icom radios by utilizing the radio's CI-V frequency data, and with non CI-V capable radios by counting the transmitted RF frequency.

With AT-AUTO firmware version 2.14 and later, the CX-AUTO may also be used to switch between multiple radios -- permitting the AT-AUTO to work with up to 8 different radios, selected via the AT-AUTO's front panel controls. Using two CX-AUTOs, one for radio selection and one for antenna selection, provides a true 8x8 matrix capability -- any 1-of-8 radios operating into any 1-of-8 antennas, all utilizing the same AT-AUTO. Convenient & cost effective!

Not limited to just the AT-AUTO, although the CX-AUTO was originally intended as a companion product to the AT-AUTO to automatically select from one-of-eight antennas, the CX-AUTO's firmware and flexible switching scheme enable it to simultaneously select multiple output combinations as would be needed to switch antenna arrays or antenna phasing networks - all without needing to change jumpers or wire settings. Merely by sending it simple serial data commands, you may select any of the possible 256 combinations of the eight coaxial outputs. As an added advantage, un-selected coaxial outputs are shunted to ground.

The CX-AUTO uses the simple but effective and robust CI-V protocol implemented by Icom and is fully compatible with any device using the CI-V system & protocol. For rigorous deployments, the CX-AUTO may also be controlled via its RS-422 port for distances up to 3600' from the shack and uses standard networking CAT5 cables and connectors. Nothing to disassemble or solder, and nothing complicated, proprietary, or expensive.

The CX-AUTO employs user-selectable addresses permitting multiple CX-AUTOs to be deployed on the same CI-V/RS-422 bus, eliminating extra control cable runs - something else that the competition can't do.

The CX-AUTO is normally powered via the front panel from the 12 volt "wall-wart" provided or from any convenient 10-15 volt power supply. However, for convenience and flexibility, the CX-AUTO may also be configured to receive DC power via the RF coaxial cable.

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Order the CX-AUTO Today!

Price: $329.00 (New lower price!)


CX Auto antenna switch. Click to view larger image. The CX-AUTO offers the following features:
  • Strong RF shielded enclosure
  • .090" aluminum, anodized and powder-coated chassis and cover/mounting bracket
  • Low loss (< 0.1dB) and excellent isolation (>60 dB)
  • Un-selected ports are shorted to ground
  • Low power operation (10-15VDC, 30mA, no output selected, 120mA w/one output selected)
  • Uses common, readily available, non-proprietary cables and connectors.
Any one of 256 output combinations are possible.
CX Auto antenna switch, internal component view. Click to view larger image. Mount the CX-AUTO in a convenient location, sheltered from rain, snow, or other precipitation. Use the four mounting holes incorporated into the mounting plate/chassis cover.

Supply 12 VDC power via the front-panel receptacle or supply DC power via the "common" coaxial cable.

Connect either a CI-V or RS-422 (CAT5) cable and set the CI-V/RS-422 front-panel switch as appropriate. Note: Multiple CX-AUTOs may be daisy-chained on the same data bus so long as each CX-AUTO is configured for the same data rate, but with unique addresses. Then interconnect via CI-V/RS-422 patch cables.

Configure the serial address and data rate via the front-panel switches. Connect the other end of the CI-V or RS-422 cable to the AT-AUTO or to the PC (via suitable CI-V/RS-422 to RS-232/USB converter as appropriate).

CX Auto antenna switch, internal component view. Click to view larger image. The CX-AUTO employs an embedded microprocessor which receives serial data commands via an Icom style CI-V bus or via an RS-422 interface and then controls 16 relays for selection of any of the 8 coaxial outputs. The serial control data is consistent with the Icom CI-V protocol and the CX-AUTO is capable of selecting any of the possible 256 combinations of the 8 coaxial outputs.

To improve isolation and performance, each coaxial output has a dedicated pair of relays to perform the RF switching. The CX-AUTO configuration yields excellent port-to-port isolation, low loss, and excellent SWR performance over singular-relay antenna switches.

The front-panel includes LED indication for each coaxial output to identify the selected output(s).

  • Power Rating: > 2kW CW key-down (SWR < 3:1)
  • Serial data control line: 5V Open-Collector twisted pair or RG-174 shielded for runs up to approximately 50 feet. CAT5 twisted-pair differential for runs up to 3600 feet.
  • Dimensions: 8.25" wide, 10" deep (11.75" overall with mounting plate), 2.5" height
  • Two-piece hardware construction with mounting holes incorporated into chassis cover plate.

CX Auto antenna switch. Click to view larger image. The CX-AUTO purchase includes the following items:
  • One CX-AUTO remotely controlled coaxial switch
  • One CX-AUTO user's manual
  • One AC/DC Adapter. 100-240VAC, 50/60 Hz input, 12VDC, 1000mA output
  • One 50' CI-V cable
  • Two 3.5mm mono plugs (for construction of additional CI-V cables, as needed)
  • One DC power plug (2.1mm ID, 5.5mm OD) (for assembling additional DC power cables, as needed)

All products manufactured by Kessler Engineering, LLC are either personally built my myself (Don Kessler) or by a select member of the Kessler Engineering staff. All products are tested exclusively by me and I can assure you of the high level of component and build quality as well as strict attention to detail.

Kessler Engineering, LLC products are therefore warranted to be free from defects in material and workmanship for a period of one year from the delivery date to the customer. During this one year warranty period, Kessler Engineering, LLC shall either issue credit, repair, or replace any Kessler Engineering-manufactured product proved to be defective.

Should the original purchaser notify Kessler Engineering of the suspected product defect, Kessler Engineering will supply instructions for returning the product. If the product is indeed determined by Kessler Engineering staff to be defective, the product will be repaired, replaced or a refund provided, at the discretion of Kessler Engineering, LLC.

No products will be accepted for return unless accompanied by a Kessler Engineering-issued Return Merchandise Authorization (RMA).

This warranty shall be void if the product has been tampered with, abused, or used in an inappropriate manner, fashion, or application.

Kessler Engineering, LLC is not responsible for loss or damage to any other equipment and does not make any claim or warranty of product merchantability or fitness. No one is authorized to assume any obligation or responsibility on behalf of Kessler Engineering, LLC.

CX-AUTO Downloads

Kessler Engineering provides the latest versions of the CX-AUTO's manual available for download.

CX-AUTO Switch Manual (updated August, 2011).