Back to working on the strobe problem. When I turned the power on to the system the position light worked fine, but the tail strobe was dead. The two wing strobes worked OK. At the suggestion of a fellow builder I switched the wires at the power supply between the tail strobe and the right wing strobe. It did not help, the tail strobe still didn't work, so I switched back to the original configuration and now the right wing started acting up also. It was intermittent with as much as 20 second delay between flashes. To find out if the power supply or the tubes are at fault I used outlet #2 (left wing) that worked consistently to test the tail and right wing strobes. The result was negative for both. Then I used the left wing strobe (this always worked) to test all three power supply outlets. They all worked OK. Then I measured all the power supply voltages. They were all correct: Red to Black (ANODE): 500V White to Black (TRIGGER): 0.05 V Oscillating It looks the power supply is OK, but the strobes at the tail and right wing are defective. Will order these tomorrow.
