Sunday, 20 August 2017

LOFAR antennas

Remember this post from 2009? Probabely not! But of course I remembered my old post as I wrote it myself ;-). Something I wanted to do for a long time is to visit and investigate this LOFAR remote site myself. I think not many people here do know about this receive station site in their village Roodeschool. With the help of google maps though it is easy to find (if you know were to look for). And so this morning I went on my bicycle to make my "tourist" sightseeing. This LOFAR RS509 site is one of many to make a array of antennas forming a radio telescope. My main interest is not what they can do with it but what the construction of the antennas is made of. I found detailed information in this PDF document.

More info about LOFAR can be found on:

LBA Low Band Antenna contains a LNA Low Noise Amplifier in the top cap. Dipole arms are from 1,38m long thin insulated copperwire as far as I could observe. Resonance frequency is 52 MHz. The groundplate is made from simple concrete mesh you can also buy at he DIY.

HBA High Band Antenna are made from alu. It consists of 4x4 dual lineair polarization dipoles housed in a polystyrene structure covered by polypropylene sheets also known as agricultural plastic sheet. Of course I could not take a look under the sheet so exact construction will remain a secret to me.

I observed another antenna at top of the first server housing. It is pointed to the nearby road. I guess it is a WiFi antenna so any maintance read out can be done from the road? Not shure why it is done like this as the whole site is connected to high speed internet via a optical fibre cable.

The whole site is situated about a kilometer from my home. And although the antennas are mainly pointed upwards I would still have doubts about interference from nearby amateur radio stations like me. Although I'm not transmitting signals 24/7 on the 6m band of course.

Saturday, 19 August 2017

Summertime updating

I realize I haven't been updating my blog for a while. I've so many ideas and so many projects I want to share. I really should get it out of my mind spending time for this radiohobby in summer. Too many things that happen in and around the house and familywise this time of the year. So instead I publish some nice summer photos from our garden to look at...

Garden July-August 2017

Tuesday, 8 August 2017

Worlds within worlds

Many of us not realizing that the amateur radio hobby and this blog (other radioamateur related blogs as well) are part of a world within a world. A kind of parallel world besides the "normal" days of life. I realized it while discussing this with my dad. Others outside this world do see this world but most of the time do not know what is really going on.  In todays "modern" world full of communication technology people share their hobbies much easier and you have many ways to find people worldwide that share your interests and hobbies. The amount of blogs, websites and forums are countless about all kind of subjects from a obscure sport to a collection of rare poststamps. We radio amateurs already had a way to contact other people with the same hobby long before others could. Logically I think we as radio amateurs are living in one of the oldest parallel worlds which we created through communication.