What is this?

This is a website were I will publish my ham radio experiments in order to make all my results readily available to anyone. Currently I'm testing some antennas for various HF bands and a power amplifier for my Yaesu FT 817 ND. I hope you will enjoy reading my future posts.
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A small power amplifier

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I want to make clear that I am not a big power fan boy, but sometimes to make a QSO the 5 W of the 817 are not sufficient. I did not want to buy one, so I went for one of those Chinese kit you can find on various sites and that are really cheap. I bought mine from Bangood for  about 30 €. The seller declared it could deliver 70 W with 5 W drive @ 13.8 V. When the kit arrived it was in a rather small package, the PCB was 10 mm x 5 mm, and no component was missing. It is labeled MINIPA 70. Unfortunately no building instructions nor schematic were given so, after a bit of googling i found this site . The following schematic was from that site. I was indeed very happy to find out the MOSFETs are some very cheap IRF530N you can easily get for 1 € each. To assemble the kit you need to do some SMD soldering, some good thin tin, flux and a decent soldering iron are needed. You should start mounting the smaller components first, then the bigger ones. The connectors shipped are...
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A small power amplifier (part 2)

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After building the amplifier we get to two critical point: interfacing the amplifier to the radio setting the bias correctly Step 1 In my case the first one was not a big deal. I took a look at the FT 817 Operating Manual, it showed that the pin labeled "TX GND" is put to ground every time you key the PTT.  Now all I had to do was to buy a 8-pin mini-DIN jack and solder two wires, one to "TX GND" and the other to "GND", and then connect them as shown in the following picture. Remember to use a decent length of wire, in my case I used ~ 1 m, to move the amp at the wanted distance from the rig. Step 2 For this step it is better to have a dummy load capable of sustaining about ~ 80 W of power. If you do not own one probably you can find another ham at the local club who will borrow his own. Remember that it is not considered good ham radio practice tuning your amplifier on the air (HI). Then you will need a power supply, in my case I ...
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My poor man CW interface

When I got involved in ham radio I was soon fascinated by CW, so I learnt Morse code and started making contacts. A few days ago I participated as a station in an award and decided to try out working some station in CW instead of my usual SSB operation. I soon got tired of sending CQ and reports by hand so I started thinking of making a CW interface with what I had at the moment. The logging program I use is CQRLOG under Ubuntu 16.04. Because I did not want to risk burning my rig I decided to use the interface I usually work digital modes with because it was insulated. This is basically a couple of insulation transformers for audio in/out and an optocoupler for the PTT signal. The latter is keyed via RTS of an RS-232 port connected to the USB of my laptop trough a converter. What I did was simply to connect the PTT of the interface to the KEY port of my FT 817. Now the software part: modulating CW trough RTS and not TX as usually done. After a bit of searching I found that cwdaemon ...
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