Antenna Disconnect


Paradan Radio Presents the Antenna Disconnect

Reduce the chance of station damage from lightning. 

The Antenna Disconnect automatically disconnects the antenna from your radio and grounds the antenna. It prevents static-discharge, surges, and lightning-strike effects from damaging your radio and associated equipment.  

The Antenna Disconnect Actuator is installed at the output from your transceiver, power amplifier, or antenna tuner in line with the antenna’s feedline.  When the transceiver is turned OFF, the antenna’s coax signal wire and shield are shorted together and grounded, and both the coax center and coax shield are disconnected from the radio.  When the transceiver is powered ON, the Actuator re-connects the antenna for normal operating. It is intended for HF operation, 160 through 6 meters, and can handle 1.5  kW.  A good earth ground connection is required for maximum surge protection.  The Antenna Disconnect is ideal for remote station lightning and static protection. 

The Antenna Disconnect Actuator comes with SO-239 coaxial sockets.  It is also available with 5-way binding posts for use with twin lead (ladder line) feed lines, such as 450 ohm lines.  To purchase, please select this option above 

12 Volt power for the Actuator comes from the transceiver.  For modern Yaesu transceivers, simply plug the control cable into the transceiver’s auxiliary power RCA socket. For modern Icom transceivers, connect the control wire to the auxiliary socket's pigtails using the crimp barrels.  Or connect the control cable to your power supply directly or through a power strip.  Powerpoles are included..  Simply turn on your radio or power supply to operate.  If you wish to leave the power supply on, then a separate unit, the optional Radio ON Detector unit is used to sense if the radio is turned on.  The On-Detector is placed in series with radio’s 12 volt power wire.

Specifications on this unit are below.


Antenna Disconnect Actuator:

1.  Operating Voltage:    10-18 Volts dc

2.  Insertion loss: less than 0.05 dB up to 29 MHz.  0.3 dB at 54 MHz, 1.0 dB at 148 MHz 

3.  Current:  60 mA when turned ON to connect antenna

4.  LED:  Illuminates green when relays connect the antenna

5.  Relays:  Two relays with 15 Amp contacts, protected for reverse spikes

6. Case: Grounded to antenna’s and Isolated from radio’s coaxial connector

7.  Control Wire: Two-conductor #18 AWG with an RCA plug.  Powerpoles and barrel connectors are included.

8.  Control Input:  Diode protected against reverse polarity.  RF filtered. 

9.  Active Lightning Protection:  Gas Discharge Tube on antenna coax input 

10.  Case Ground Stud:  One-quarter inch with washers, lock washer and nut

11. Case: Die-cast aluminum, black paint, white print, water resistant

12.  Size: 4.8 x 2.6 x 1.6 in., mtg. tabs w/4 holes @ 5.25 and 1.5 in. centers

13. Weight:  13 oz., 390 grams 

User Manual: Download PDF

Radio ON Sensor

The ON Sensor determines if the transceiver has been turned ON and, if so, it provides power to switch the Antenna Disconnect Actuator.  The ON Sensor is needed if the associated transceiver does not have a 12 volt power output terminal or socket, and you wish to keep your transceiver's power supply turned on.  
The ON Sensor is placed in series with the transceiver’s power wire. The connectors allow easy hook up to most power supplies and radio power cables.  The Sensor comes with 3-way banana binding posts, ¼ inch ring terminals, and a jumper with Powerpoles.
Current sensing is accomplished by its unique method of using a fuse for the sense element.  Different value fuses allow the ON-Sensor to work with all radio’s, QRP to QRO.  

Antenna Disconnect Current Sensor:

1.  Operating Voltage:  10 to 16 Volts dc
2.  Current:  10 mA Quiescent, 60 mA when Activator is powered ON
3.  Current Sensing Resistor:  Fuse, 40, 25 or 10 Amp ATCO fuse
4.  Maximum Pass Current:  30 Amperes
5.  Input Connector:   #12 AWG Wire with Powerpoles or ¼ inch ring terms 6.  Output Connector: 4-way 30 A binding Posts (wires, banana, ring, spade)
 Includes a  6-inch jumper #12 AWG wire w/Powerpoles.
7. Actuator Connector:  RCA Phono socket
8. LED:  Illuminates green when supplying power for switching Actuator.
9.  Case:  Aluminum, painted black, white screen printing
10. Size: 4 x 3 x 1 in., four mounting holes @ 4.5 and 2.5 centers
11. Weight: 6.5 oz., 200 grams