SMTCL – Stack match control and universal control

(by S56WIX and S55O)

 

MANUALS and DOCUMENTATION

PICTURES

 

Doesn’t everyone hate it when, while using a turn-knob antenna switch you get the wrong antenna or wrong stack position? I do!

So thanks to Matej S56WIX and Aleš S59MA we succeeded in finishing this simple controller project, which I hope will help some hams get rid of the same problem and improve the antenna switching process. Seldom hams improve their operating posts and IMHO most of the hams have a 10-20% margin of improvement there. This is a simple controller that was made to satisfy our needs at the S53APR or S51A station.

 

Users that bought or are using this controller: S51A, S50K, S50XX, IV3TMV, EC2DX, S53F, S57L, S51ZJ, S52X, S50LD, S51DS, S58AF, S50B, S51F, ….

 

My thanks for the redaction of the English manual and the layout goes to Collin GM0RLZ.

 

 

 

SMTCL is an universal controller for controlling stackmatches (SJ2W and 4O3A stackmatches), antenna switches, rx antennas (k9ay, DHDL, beveriges,…), and other 12V hamradio gadgets.

 

The circuit contains 8 power outputs for controlling 12 volt ​​relays with one common point. Outputs can be controlled positively by using a UDN2981A (or TD62783) with a common ground, or with a negative control, using a ULN2803A with common +12 V. The circuit lets you connect 6 push button switches and a PTT interlock (active when grounded). Pressing one of the push buttons will select the active outputs. When the PTT is grounded an interlock circuit prevents the user from switching between outputs when in transmit mode (PTT interlock / hot switch protection).

 

The circuit logic is controlled by an ATtiny26 AVR microcontroller. The circuitry and software are designed to control the SJ2W stackmatch, however the microcontroller contains three additional programs which enables the controller to be used for other switching purposes, such as a 6x1 antenna switch.

 

Software version 1.2 has now 4 different programs.

 

  1. SJ2W stackmatch program:
    1. Control of up to 3 antennas with the SJ2W stackmatch.
    2. Pressing shortly one button activates the antenna and if others are active, adds it to the stack.
    3. Holding one button for more as 200ms selects only that antenna (if antenna 1 and 2 are active and you press for example antenna 2 and hold it for 200ms, now only antenna 2 is active).
    4. Since the logic for the control of the SJ2W stackmatch is different as the logic for the LED diodes, different!!! outputs are used to lit the LED’s as the outputs used to drive the relays. (using 4 outputs for the antennas and 4 outputs for the led’s – 3 antenna LED + 1 Stack LED)

 

 

Ant combination (SJ2W)

A (K2)

B (K3)

C (K1)

K4/K5

A

1

0

0

1

B

0

1

0

1

C

0

0

1

1

A+B

0

0

1

0

A+C

0

1

0

0

B+C

1

0

0

0

A+B+C

0

0

0

0

 

 

  1. 4O3A stackmatch program:
    1. Same as the SJ2W program, but with a different logic

 

Ant combination (4O3A)

A (K2)

B (K3)

C (K1)

K4/K5

A

1

0

0

0

B

0

1

0

0

C

0

0

1

0

A+B

1

1

0

1

A+C

1

0

1

1

B+C

0

1

1

1

A+B+C

1

1

1

1

 

  1. Antenna switches

Up to 6 push button switches can be used (up to an antenna switch 1x6). Pressing the appropriate button, switches on an individual antenna, the other antennas are off.

 

  1. Independent ON/OFF control for up to 6 outputs

The independent on/off control program is selected by holding down buttons 3 and 6 during power up of the controller. Electrically identical to the previous program, only the buttons function as an on/off switch for each output, where channels do not affect, one another

 

 

 

 

If you want to make it yourself, drop me an email, I can make some more PCB’s for the SMTCL or SJ2W Stackmatches.

 

Have fun with the projects!

 

Boštjan – Ian S55O