Integration testing
So, finally I can put the three main boards together. Capacitors, Inductors and controller board. Also I connected the communication board and made the connection with the PC via USB cable. Power up the complete setup and start the application software on the PC. We see now a working tuner ! which is not tuning yet, but we can click on all buttons, we can upload new application software, and we can play with loading channels with C/L-settings.
Before we are going to put power on the input with a dummy load connected to the output, we are going to test a few things to be sure we are not going to blow thing up,.....
Test program:
- Test the capacity of the C-train by activating all the C's one by one, and test also the total C-train by adding C's one by one
Measure at the output pins, and shut all the C's and L's off. Put the tuner in the CL mode.
Measure the C at the output. All the relays are working, and there is a bit of overlap in the values at a change of the higher bit.
- Do the same test with the inductors. I did it also with the inductors, but my testing device was not so accurate, that it could see
microHenries. So it is measured, and by adding more inductors, the total inductance increased. I leave it for now.
- Test the beep, it was put in the system for creating a constant input for the microphone for generating a constant HF signal for
testing the tuner. But used my keyer for this purpose. But it beeps,....in the PC
- Test the store and read function of the EEPROM memory, did for the whole 7MHz band and it works fine.
- Test the clear channel and clear all functions. Also tested and it works fine.
- The tuner is not finding a good tune on his own, by running a algorithm, you have to do that yourself and store it in the chose
channel. It works OK. Basically the algorithm is not that difficult to add this software in the micro controller, but probably Norbert
had his reasons not to do it.
After that do the following:
- Connect a transmitter to the input and a balun to the output. I use a big 800W balun. This balun transforms a balanced signal into
an unbalanced signal.
- Connect the unbalanced signal of the balun to a dummy load. I use my 1kW dummy load.
- Give a little bit of power to the input and check whether the frequency is read correctly by the tuner
The frequency is read by the tuner over all the bands and 5W is enough to trigger the measurement. I could tune easily, because
the dummy load is really 50 ohms over the complete HF amateur band.
- Now I connected my 20m inverted V to the tuner. Set the transmitter on 14.100 MHz and on 5Watt. The antenna was a little bit of
SWR 1-1.0. With a few changes of the L/C-setting, I could get it 1:1. Storing was also easy. Just STORE. This way I set all the channels
(14.0125 to 14.3385 are the centers of the channels) to a practically 1:1.0x.
- Now I connected my dipole antenna. This is a dipole on 6-7 meters high, horizontal, fed with 17meters coax, followed by a balun
and 5 meters chicken ladder of 300 ohms. Not exactly the best configuration, but it was optimized for 40 meters and 80 meters
(with two coils about 5m from the center dipole, followed by 2.5 meter additional wire at each side).
Now I could see that the tuner really has something to tune, to get it 1:1. The good news is that I could tune the 80 meter band
completely to 1:1. The bad news is that I had problems with incoming radiation, which crashed the tuner software if I increased
the power. I am not sure whether the tuner has been crashed, or the USB software in the PC stopped working properly. After
some tests, it was clear that the USB channel software crashed. Some ferrites helped a bit but I can not go further than 300W.
I want to wait until I completely finished the tuner in the box, and place the tuner away from the PC and the communication
board until I am going to take measures against the unwanted radiation.
But at low power I want to tune the 10m band. And that is possible with in 1:1.5 and efficiency of 96.5%.
In general we see sometimes a chash of the USB pot in the PC and sometimes wrong commands sent to the PC.
Conclusion is that the tuner works fine, but the radiation is something to work on. Maybe I have to do something about earthing ??
Anyway, enough until now. Wait for the box to build in the tuner.
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