Return to TiltPlate page

  Return to FAQs page

     KARLock - Optional Gravity Lock for the TiltPlate


Click to jump to the KARLock  Videos


Click for Installation Instructions

Click for STACKABLE adapter tube picture

Click for Mini-TiltPlate mounting picture




The KARLock is an optional locking device for your TiltPlate.  If you live in a high wind area or just feel more comfortable with a device to prevent the antenna from lifting in high winds, you may want to consider a KARLock for your Tiltplate.   About 60% of our customers order the KARLock.

The lock is "gravity powered" and made up of three components: the pivot block, the catch rod, and the catch plate. 

The pivot block attaches to the moveable TiltPlate.  The pivot block is machined from a single block aluminum and attached with set screws.

The catch rod is shaped to catch the latch and pull tight when the moveable plate lifts due to high wind.   It is cut from 1/2 inch aluminum plate for high strength and low weight. 

The catch plate is 1/2 in thick aluminum plate.  It is secured to the mast using 2 inch (or 2 1/2 inch) U-bolts from DX Engineering.    A heavy duty stainless steel catch bolt is mounted on the plate.

Operation - in the normal operational position the catch rod swings freely about 1/4 inch below the catch bolt.  When tilting the tower over for maintenance the catch rod pivots clear of the catch bolt well in advance of any movement or separation of the Tiltplates.    In the event of high winds, as the moveable plate lifts, the catch rod engages the catch bolt.  The lifting motion is stopped.   See video below. 

Design features

Does not require the user to climb the tower to lock or unlock in normal use

Does not require cables, poles or other attachments to lock or unlock in normal use 

Does not add additional wind load

Is simple, reliable, and weighs less than 5 pounds

Uses top quality parts consistent with the TiltPlate itself 

Prevents antenna lifting in any wind speed up to the maximum 100 mph rating

Can be installed on all TiltPlate models.

Can be installed on an existng TiltPlate in the field by the user. 

Can still be opened in the event of icing

Thanks to Kirk/K6KAR for encouraging me to develop this option and thanks to both Kirk and Jerry/K3BZ for volunteering to test the the prototypes.  During the development of the KARLock, we looked at wind powered locks, magnetic locks, and other ideas sent in by folks.  In the end, we settled on a gravity based lock that would work best for the wind speed rating and all of the antenna configurations supported by the TiltPlate. 

Read the KARLock reviews on eHam click here

Pictures, Video, and Installation instructions

TiltPlate in normal operating position
Lock arm not engaged (swings freely about 1/4 inch below catch)

Tilting the tower
The tower is beginning to be tilted over (only about 5 degrees in this picture)
Catch rod is moving away from catch

Lock engaged - simulated high wind condition
In the normal operating position, if the moveable plate lifts, the lock will engage
and prevent further movement

Pictures below show the KARLock at rest and engaged. 
Monster model TiltPlate with SteppIR DB36
Provided by Rick / NK7I

Top pic - at rest

Bottom pic -- KARLock engaged in windy conditions

Components - close up

Pivot Block with set screws and stainless steel pin for catch rod

Catch Rod

Catch Plate, stainless steel hardware, DX Engineering U-bolts
Accepts either 2 inch or 2 1/2 inch ubolts



In order to use the KARLock on the Stackable model TiltPlates, an adapter consisting of (2) U-Bolts and a short section of Aluminum mast is required.  The mast U-Bolts on the Stackable TiltPlate are located on the other side of the mast plate.  Click here to see the Stackable TiltPlate page for more information.



KARLock CATCH PLATE mounting location for the Mini-TiltPlate

The Mini-TiltPlate supports the KARLock in the STACKABLE and NON-STACKABLE configurations.   The picture above shows the location of the CATCH PLATE using the STACKABLE version of the KARLock. 


KARLock Videos

The video above is about 1 minute long and shows the KARLock in operation.   The file size is about 8 mb.


Here is a YouTube video showing a TiltPlate and DB18 in a storm without the KARLock.  Provided by Kim / K4ATX.   Kim estimated the gusts at about 30 MPH.


Installation Instructions

Click here for Installation instructions


  Return to TiltPlate page

  Return to FAQs page