Maintenance Notes on StackMatches
20 Meters
Installed indoors September 2001, still in service.
15 Meters
Board burned, apparently from lightning, discovered September 2003. Replaced with newly-purchased StackMatch board October 2003, Spare controller placed in maintenance kit oh shelf above radio closet.
10 Meters
Discovered in September 2005 that the combination of Antennas 2 and 3 (Europe and US/JA Top) would not work -- high SWR and no received signals. All other five combinations are OK. Swapped in new board and took the bad one to US for repair.
Spare Board (formerly from 10 meters)
13 November 2005
Used newly fabricated Specialized Experts dummy loads and test cable kit to diagnose problem. Discovered that relay 1 (which is supposed to pull in and take Antenna 1 out of the toroid load) was showing partial continuity to BOTH the NO (as it should) and the NC (which should be infinite) poles. Replaced Relay 1 but still have the same problem. Conclusion: There is a burned domain on the board that can't be repaired. thus this board is good for all but antenna 2/3 combination.
11 September 2013
K8LEE was going to take one controller board and two antenna relay boards, all three labeled "bad" to Ohio for repair, but then decided to leave them here. Darn.
9 March 2014
Bad SWR on 10 meters when other ran a single antenna was selected. Swapped in a good StackMatch box labeled December 2005. All ports work fine in all combinations. Installed this box permanently at 10 meter position indoors. Also, on 20 March I found a StackMatch outside relay board in the "Foot Switches" box. I added this and the set of StackMatch spare parts to the package to take to Idaho and then send on to K6AM. Returned the bad box to Idaho, marked "Bad Old 10." Sent to K6AM for repair.
4 April 2015
The above box was repaired by K6AM, shipped to Idaho, and then taken to Curacao in November by W0CG. In stock now in West Bedroom, left closet, left shelves, painted tan.
22 October 2015
This box was placed in temporary service by W0CG on 10 meters, verified to be working correctly, and returned to the shelf in the West bedroom.
StackMatch Specialized Expert's Maintenance Kit Contents (W0CG):
* Three dummy loads, 50 ohms
* Good controller box, tested 100% good Nov 2005
* Test cable to connect controller to StackMatch board under test and to RigRunner for DC
* Old controller box with broken parts -- spare parts source
* Old burned board from 15 meters -- may be operable, but best treated as spare parts
source. Has no SO-239s on the board, nor bo metal body
* Blue body box for board on tower
* Kit of spare new diodes and relays
* Schematics and troubleshooting guide
Theory:
With No DC applied, the IN relay is open and RF goes through the toroid to all antenna ports. Removing an antenna from that mix requires that the control box key the appropriate of the 1, 2, 3, relays on. That will drop that antenna out.
When just one antenna is selected, the IN relay is keyed on as is 1, or 2, or 3 according to the desired antenna.
W0CG Procedure:
Connect all three 50 ohm dummy
loads to the antenna ports
Connect box to the test cable with the switch on the other end.
Connect switch to DC power with PowerPole connector.
Diagnose.
Look for bad diodes, relay, or toroid, based on the above theory of
operation.
The IN, 1,2, and 3 relays have 270 +/- 10% ohms. Measure the coils from either your cable end if the StackMatch is up on the tower, or take it down to measure.
You should measure from each wire or terminal to the ground wire or terminal. Remember to figure the amount of resistance in your cable.
The relays will pull in at 9 VDC. They will draw 40 ma each. But try to use cable that will deliver 11-13.8 VDC to each relay.
Set the control to pull in a single antenna at a time. This will apply 12V to the IN relay and one of the antenna relays (1,2,or 3) This will take the torroidal transformer out of line.
You can measure a DC continuity resistance to each antenna. For instance antenna 1 position should have 0 ohms from its SO239 port to the feedline port. The other antennas will be at DC ground through the torroidal transformer.
Measure each antenna port for continuity while connected.
You may also use a dummy load to test each antenna port for 1:1 or close to it SWR.
Power off is means you have RF to the full stack. Three dummy loads in each antenna port should deliver a SWR of less than 1.2:1 at the user frequency.
Test each combination for SWR to be below 1.2:1 at each combination of antennas.
With a 12V DC power supply and some jumper wires. Test the StackMatch relay box for proper operation without the controller. Use three dummy loads.
Test single antennas by placing 12V on the IN relay to ground and any one of the 1,2, or 3 antenna relays. You should see an approx. 1:1 SWR
Test multiple antennas selection by no voltage on any relay, or full stack, You may now place 12V on any antenna relay 1,2,or 3 to pull it out of the stack. SWR should remain good.
If not the controller may be defective. Test the controller output voltages to correspond to the above single and multiple antenna function. Use your schematic to derive which diode may be bad.