StackMatch for Verticals User's Guide

Thank you for your purchase of a WX0B StackMatch.

Users Guide

This WX0B StackMatch can be used for stacking two or three monoband verticals. It will give the user the ability to feed two or three verticals in phase giving a broadside pattern when spaced properly, and a end-fire pattern in two or three directions when each antenna is selected by itself.

Also Three verticals may be hooked up and used to achieve similar results in three directions. The procedure below is for two antennas but also can be expanded for three antennas by using the third antenna port. The three antennas are set up in a delta pattern or triangular pattern, equidistant from each other.

Set Up

The control box cover should be removed. A grommet is provided in the back to push the control cable through.

Wire the switch as described in the StackMatch user's guide by terminating the wires on the terminal strip.

Terminate this cable with a plug such as a Cinch Jones Plug a foot or so after it leaves the box to make it easy to disconnect the box from the cable.

Remove the cover of the StackMatch and push the cable through the rubber grommet in the chassis and up through the hole in the circuit board. Strip the 4 wires and terminate them in the matching terminal strip. Again make a matching plug and jack combination pigtail a foot or so long to make connecting and disconnecting the StackMatch easy.

Use the TY-WRAP™ supplied to secure the wires from pulling out of the boxes. Replace the covers and screws.

Weatherproofing

A word about weatherproofing the cable connectors and box. There are many viable techniques to weatherproof your connectors, please use your favorite one to keep your outside connectors protected. If you live in a very harsh and wet environment you may wish to add a bead of silicon rubber, to the top cover edges if the paint on the box didn't fill in the small gap in the overlapping metal of the StackMatch itself. Do not seal the bottom since the ability of having the box breathe will keep it dry from condensation which normally builds up in outdoor boxes. It will also allow water to weep out of the box if you do have a leak. The board is coated and suspended above the box, and all hardware is stainless steel. All relays are sealed. This unit should give you very long service.

Power Cord Assembly and Testing the StackMatch

Build a two wire power cord which comes from you 12V DC supply in the radio shack. Inside the control switch is a 1 amp fuse in line to protect the supply from shorts. There is a 5x20mm 1Amp fuse in line with the 12V line on all new StackMatch switch boxes.

You can test the system in the shack to make sure you have the proper connections by plugging in the 12V connector into the back panel power jack and running through the combinations while using an ohm meter to test for continuity from the feedline port to the proper antenna ports ( See description in next paragraph). You could also use dummy loads and your transceiver to verify the system. Please verify that all relays are switching correctly. If not, review your wiring and trouble shoot by testing that the 12Vrelay coil voltages are getting to the proper StackMatch terminals on the terminal strip.

Test the unit before you install it to verify that when it is off or if "ALL " is selected that the feedline port is connected to antenna 1,antenna 2 and antenna 3 connectors. Now select each antenna separately and verify that only the selected antenna is connected to the feedline port.

Strain relief your cables with the Ty-wrapsä included and close up the boxes with the screws and hardware provided.

Erect the two verticals so that the broadside patterns and end-fire patterns are oriented in the desired direction. Space the verticals from ¼ wave apart to ½ wave apart. If you are using three verticals erect them in a triangular pattern with .145 to .25 separation. Model your antennas to verify the pattern you are seeking is correct.

Connect two feed lines which are .375 to .41 wavelengths long at the desired band of operation. Remember to take the feed line velocity factor (VF) in mind when constructing them.

Place the StackMatch for Verticals in the center of the array, and ground it to a ground rod. This can be done by using a U-bolt to clamp it to the ground rod. This will provide a good place to mount the box and keep it off the ground. Scrape the paint off the cover where it comes in contact with the ground rod if you wish to assure a good connection to ground.

Connect each antenna to the StackMatch with the .41 Wavelength feed lines.

Connect the radio to the feedline port with any length of 50 ohm coaxial cable.

Controls

The StackMatch control switch box has a rotary switch and three LEDs which display the antennas selected.

Operation

By rotating the selector switch to ( lower two LED on), you will feed equal power to the two verticals and achieve a broadside pattern.

By selecting either antenna 1, antenna 2 or antenna 3( if in a three element array) you will have created an end-fire pattern in the direction of that antenna. The un-selected antenna(s) become a reflectors due to the effects of the feedline stub.

You may find it interesting to model this array with your antenna software to determine the gain and pattern for the spacing you have chosen. Just use +J 65 to +J100 ohms as your "load" placed at the feedpoint of the verticals. Your antenna software manual should have a discussion of how to create "loads" for the antenna feedpoint. The 65-100 ohms of +j impedance is what you will see from the stub when that antenna becomes a reflector. This is like adding a coil to the feedpoint to lower the resonant frequency of the vertical by 4-6 %. This is typical of what the feedline will produce over the entire amateur band. You will also see the pattern is very forgiving and will provide useful gain over the entire range.

In a two element array select both antennas for Broadside Gain. You will see 4.0 dB gain over a single vertical if the spacing is ½ wavelength between verticals. For 3/8 wave spacing the gain will be 2.4 dB over a single vertical.

For The End-Fire mode you will see from 3dB to 6 dB gain depending on spacing.

Example of a 3 element array: To make a simple 3 element triangular array. build and three vertical dipoles and mount them from the same tower. Pull the middle sections away from the tower and fold the bottom ends back into the tower. Space the dipoles as you would your guy lines, 120 degrees apart. Feed as dipoles from the StackMatch mounted half way up to the tops of the dipoles. This makes a very effective array. Some hams have made their dipoles out of the guy wires. This is what we do at WX0B. We can see from 15-20db Front to back off this antenna on 80 Meters.

As you use the system you will find that listening to signals will give you an idea of its performance over a variation of receiving angles. Verticals have a low take off angle and will respond to low angles better as well. This makes them an excellent DX antenna.

BIP-BOP Operation for a Two Vertical Array

For two monoband verticals it is possible to accomplish and in phase braoadside pattern and an out of phase endfire pattern.  Also by using the feeline stub technique as outlined above your verticals can have the parasitic reflector when one element is driven alone.

The StackMatch may be cabled to give BIP-Bop functions to two mono-band verticals. The configuration of the StackMatch would be to have the two vertical feedlines connected to the 3 and 1 ports of the StackMatch. Place a T connector in line at the lower antenna port 1 and connect a 180° delay line from one end of the T to the middle (port 2) antenna port. The delay line is accomplished by making a 1/2 wavelength transmission line from 50 ohm coax and connecting it to the middle (2) antenna port of the StackMatch. Don't forget to figure in the velocity factor of the coax you use to make the delay line. Connect the port 1vertical to the T connector as well. Follow the instructions of your antenna SWR analyzer if you use one to make this delay line cable as accurately as possible.

Modify the control switch and relay board per the instructions found in the BIP BOP applications note found in the applications notes section of the web site under "Products".

POWER HANDLING, MAINTENANCE, HOT-SWITCHING, ETC.

Under normal conditions the StackMatch would not be hot switched. But as contesters know, it is inevitable that at some time either a wrong antenna will be selected or a hot switch will be made in the heat of the battle. The StackMatch has been designed with this in mind. You will not harm the unit with an occasional mistake.

Actually, to keep the contacts from silver oxide build-up, the manufacturer of the relays recommends that these units be hot-switched occasionally. So once a month or so, apply 100-200 watts of power to the unit and run through the positions to keep them clean.

We hope you enjoy your WX0B StackMatch. If you have any question whatsoever, please phone or email us. We are glad to assist you in whatever way we can.

Array Solutions
350 Gloria Rd. Sunnyvale, TX. 75182
Phone 972.203.8810 Fax 972.203.8811

E-mail wx0b@arraysolutions.com

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