We have seen a lot of heat in TX7 the past two days. We were a bit concerned when a hole was burned into a circuit board of the TIGRE. The TIGRE is not a tiger; it's a major part of the control system for the transmitter. We had been having trouble with it for several weeks. Once we smoked the board, we had to remove the unit and repair connections that had been severed. Once we put the whole thing back together, we were relieved that the TIGRE was back to the way it had been operating.
Then two other problems got our attention. One power supply failed. It was replaced with a spare unit. Then we worked on the original data link problem that had plagued us for weeks. We finally figured out that the circuit board shown to the left was defective. We replaced this one with a good spare board. The data link went away! TX7 was then able to respond to operator command.
We turned on the cooling system and found that we had some faults to clear. It took some climbing and poking various connections to get those problems worked out. We could not proceed to the next stage without those faults being cleared.
The next stage was to get heating to work. The power amplifier (PA) tube had been simmering in the preheating stage for weeks. Now it was time to get it fully heated. The transmitter took the command as if it were not a big a deal. It was definitely a big deal when we saw this display with no faults related to this stage! Now we can heat the tube as part of its break-in period before the transmitter puts out an RF signal.
Now we can work on the RF section. We need to check out the RF driver and then the PA. We need the antenna connected for the PA test, so worked out well that the RF duct is now done.