Thursday, October 12, 2017

Failed projects and experiments

If you read most of the blogs about amateur radio it's always about successful projects and experiments. I don't believe that every experiment can be successfull, or I might be the only experimenter that is most of the time unsuccessfull. I can't tell you the numerous times I setup a antenna and it didn't work at all. Electronics that don't work. Software or hardware that isn't capable of something you need for a experiment. Failing test equipment and failing equipment. I always have many ideas but most of the time it just is in my mind and sometimes things are impossible or is just too pricey. Most important is that you don't give up! In the end you will succeed or come up with another solution for the same challenge. Since a failed project is not a problem but a challenge!

Some of the projects that (partly) failed:

Well, I'm a believer of making things. But sometimes you really get crazy when you spend a lot of time on a project and it isn't working the way you want. Remember my USBlink digital modes modem? When I saw G4ILO made one I made my own design in 2010, it wasn't working at all. After some quetions in a hamradio forum we finally found the fault a year later. I finally used this modem for the first time in Denmark this year and it functioned without any problems. Back home I want to make a setup battery powered and portable. The modem functioned on PSK with FLdigi but doesn't TX with WSJT-X on JT65/JT9/FT8/WSPR. Strange? After some tests it seems it doesn't work when the radio is not on a power supply. It has nothing to do with low voltage, even a external 12V battery doesn't solve the problem. Till now I can't find why this occurs so probabely go for another solution, building another interface.

In 2012 I wanted to make a simple endfed that would be reproducable with simple hardware that everyone could get at any DIY store. However the theory and experiments you find on the internet didn't work for me. I did a experiment and in the end I had a working antenna but it wasn't as simple as I thought. For me this was actually a unsuccessful experiment but I learned a lot from it. Not that I plan to make another endfed as PE1BVQ Hans made a well working 3 band endfed for me that served me well on several /P activations.

The radio shack ground myth. Well I made something working I thought. I made a lot of effort to study RF ground but it still is a pitfall. I think the system I use is working well though I have to choose between safety earth and RF ground with a switch. When I had problems with interference on my VDSL modem things got worse when I used the safety earth (switch closed, earth from radio equipment to earth electrode). When I opened the switch and used just the counterpoise it was a little better (but still there). So, the switch thing is not really a need after all. Is it a failed experiment, not really but my thinking was just wrong. You don't really need a earth at your equipment and if so you could try a counterpoise. I added a 1:1 balun just after the tuner to the vertical and added a ferrite ring between earth from main earth point at the powersupply to the counterpoise. Might be I'm thinking wrong again but in practice it works for me. This way the counterpoise is probabely not working but it doesn't harm as well.

Last year I experimented with a S-Match antenna tuner setup after I purchased a homemade QRO endfed tuner. But things went wrong and I blew the MFJ-259 analyzer. A classic example of failing equipment. And it was my own fault. However I was impressed the S-Match still got a 1:1 SWR with just a meter of ladderline on 30m. Did some experiments after this disaster and it was successful but need to do some more experiments to get what I want.

In 2014 I played electronics engineer. Shouldn't do that, not really capable of it. I destroyed the TX/RX relay with my big soldering iron and blew the finals. Never wrote about that, it was my own stupid fault. At that moment I had it with electronics and sent the amp to PE1BVQ Hans to play with it. However he repaired the thing and gave it back. So a big thanks to him although I never had the intention to play QRO. It might be interesting for a portable experiment in the future.


PA2RF said...

Onze hobby bestaat vnl. uit 'trial and error'. Als je niets probeert maak je ook geen fouten. Goed dat je deze info deelt !

Hans said...

Hallo Bas, inderdaad de meeste verhalen op de blogs zijn positief. Bijna nooit geeft men toe dat ze bijvoorbeeld iets al 2 keer verknald hebben door een stomme fout.
Ik sluit mij volledig aan bij mijn voorganger PA2RF.
73 Hans, PE1BVQ

PE4BAS, Bas said...

Dat is het mooie aan onze hobby. Alleen is het wel vervelend als er iets kapot gaat wat je zelf niet kan maken. Dan gaat het weer geld kosten en dat is natuurlijk weer niet de bedoeling. 73, Bas

PE4BAS, Bas said...

Hallo Hans, nou ik geef het dus wel toe dat ik veel fouten maak. Vroeger in het begin van de 27MC rage had ik ook wel de bijnaam "sloper" omdat ik in zo'n bakkie moest en zou kijken en liefst overal aan draaien om te kijken waar het voor was. Zo heb ik heel wat om zeep geholpen maar ook wel weer wat van geleerd. Zo ook met antenne's maar mechanische dingen zijn vaak wel weer op andere manieren te verhelpen. Het is bij mij ook vaak tijdgebrek, dat gaat het te haastig. Zo ook bijv. bij de ombouw van de FT817 waar ik de flatkabel raakte met de soldeerbout, dat was fout maar gelukkig deed ie het nog. 73, Bas