VK Logger Ham Radio Forum Archive

Just wondering if your relays are actually made for 24V. A 12V relay normally switches easily with 10 or 11V.

This is an extremely good question and I think something overlooked in a lot of antennas. I have seen sparks leaping a couple of inches from a the disconnected end of a long wire antenna under certain wind conditions. The effect is not just limited to HF, I have also seen sparks jumping from the inn...

I would suggest that rather than flat strip you consider a section of angle or U-channel. The angle or channel webs could be removed for a short length around the bends, or alternatively just notched depending on how pretty you what the bends to look. You could make the angle section by folding a th...

Here is my opinion. Step 1 is not to use pl259/so239 connectors instead use good quality N connectors which provide a watertight connection to start with. Step 2 is to heatshrink a sleeve over the back of each connector where it is not usually waterproof. Many connectors now come with a suitable pie...

Yes I agree the standard message structure of JT65 (and FSK441) gives what is required for a minimal QSO and shrinking this down in any way would seem to make the QSO invalid. However if you look at many DXpedition or HF contest QSOs these rules are broken. I tend to think that technically to exchan...

Terry ZL4XX and myself will be heading to the Knights point RE46og. Will have 6m, 2m, 70cm, and 23cm equipment. We will certainly be looking out for any propagation across the Tasman.

Regards
David ZL4DK

I don't believe that a little QRP station has any less rights to call on the calling frequency than a QRO station, and indeed I believe the majority of QRO station operators believe this also. I don't believe multiple calling frequencies are a good idea. The whole idea of a calling frequency is to h...

Occasionally I have noticed some weird anomolies on the Marinetraffic.com website. In the form of ships that seem to be in rediculous places with no obvious way of being received. Usually this spot also involves some corruption in the data and I am wondering what could be going wrong. Possibilities ...

I've just recently got AIS receiver from MT and have installed it on a small southwards pointing Yagi (not yet up the tower but sitting on verranda). The station number is 1441 but my callsign is currently incorrect in the station id. No great DX yet. Partly due to lack of ships in the direction I c...

I have been testing and tuning this amp over the last couple of weeks. Initially I had trouble getting much power out. Looking closer at the output tuning with the help of Peters (zl4lv) VNA and also consulting Mats himself, we came to the conclusion that the cavity was just a little too low in freq...

I might have to pull the pin on my plans. Heavy rain on the West Coast has caused slips closing the road. Its likely to be opened again by the weekend but more heavy rain is forecast. I doesn't look very promising. It may be best if I just operate from home.

David ZL4DK

I'm planning on driving through to the West Coast and setting up at Knights point again. The weather looks like it won't be great but lets hope for some DX across the Tasman. Will have 6m 2m 70cm and 23cm. Probably be joined by Terry ZL4TAE.

Regards
David ZL4DK

And one more photo showing the GS15b tetrode itself. The one on the left unmodified and the one on the right with a cooling jacket fitted. IMG_0036.JPG We used a slightly different method of putting this together than reccommended. First we braised the compenents of the jacket together. Then after m...

Yes Roger, You are correct with the Cambridge knobs. Some of them clean up quite nicely. The amp is suppossed to put out 300-400Watts depending on how hard you want to push it. The picture below shows all the bits of brass and copper(for both amplifiers) before we assembled them. Peter ZL4LV did mos...

Hugh ZL4HL and myself have been building 1296 amplifiers using the GS15b Tetrode from the design by KD5FZX http://www.nd2x.net/kd5fzx-gs15s.html with the help and lathe work of Peter ZL4LV. Hugh has his running now and is having great success with it on EME. I have completed mine but have yet to pow...

I would strongly reccommend running a second coax up the mast for a recieve line. Since this will be on the output of your preamp it doesn't have to be super low loss. If you don't you will need two high-power/high-isolation relay which as you have found is difficult to achieve at 1296 and it is com...

I use Eagle which may not be ideal for what you want to do, but I have successfully used the manual track drawing tools to lay down specific width tracks for 50 ohm striplines etc. I have also used microsoft paint (mainly for touching up scanned images). I found using paint that you must save the fi...

How about "Electricity will always take the least resistance path to ground". This is so almost true that many people say it without thinking too closely about it. The real truth is of course that electricity flows according to ohms law, so that where there are two paths to ground of diffe...

Yes one of the best Es openning I have heard. In the morning I found that 6metres was full of huge signals from North Island stations many working VKs (which were only faint here, possibly backscatter). I worked one VK station via the Auckland 6metre repeater. In the early afternoon I noticed I coul...

Thanks Mark, 100mm of tubing sounds fairly short, considering that there is 2kV across the water in this length (1650V on TX when the screen supply is energized). I read a note somewhere where someone was having trouble with leakage current and the green tinge forming and replaced this tubing with a...