I have explored a lot of ideas about the user interface and finally decided to go back to my tried and tested approach and use a tab in my Stationmaster software for the user interface. It gives me a lot of flexibility.
At a basic level, I can envision buttons for "measure power", "tune", and "bypass". When operation of relays is called for, the tuner might come back and ask power to be reduced. If one of the software controlled radios is in use, the power can be reduced by the software, otherwise, user feedback provided.
If I ever get ambitious, I will display a Smith Chart on the screen and display the path of the tuning on the Smith Chart. I will see.
For testing, I will use a simple Command Line Interface (CLI) like the one I use in the tuner simulator and I described earlier.
Adjusting Amplifier Power Level
I have three radios, a modern Yaesu FTDX10 and an old Ten Tec Omni D from the 1980s (and a Ten Tec Jupiter that is a new acquisition). The case for the Yaesu radio is simple, it has a nice API that I am currently using for the contesting interface so I will not discuss it anymore. For the Ten Tec, it would be good if I don't have to manually reduce the output power (putting 100 watts into a 10:1 SWR would not be great). Below is the schematic of the Ten Tec ALC circuit (I have used the same reference designations in the Ten Tec manual). There are two controls in the radio. The drive which controls the level of the signal (CW or phone) applied to the low level driver and ALC which controls the threshold at which the forward power signal is used to roll back the gain of the low level driver. The ALC signal is single to the base of Q8 is the rectified output of a Brune bridge fed through a 10K resistor.
I will have to experiment with injecting current into the base of Q8 also from a 10K source (maybe with a diode blocker so It does not interfere with normal operation) to see if I can automate the output power adjustment. To implement the idea, I will have to build a new enhancement box for the Ten Tec (
https://ad2cc.blogspot.com/2022/04/ten-tec-transceiver-enhancements.html). This will not be the only enhancement that needs to go in.
In the mean time, I will use the combination of power measurement in the tuner and manual adjustment of the radio to set the desired power level for tuning and for driving the power amp.
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