Antennas for System BLUE - Mini Guide

[LaurentB]

Thanks Richo,

I'll start with a 60cm diameter, 12 turns.

Hope I'll be soon at position 1 in blue queue

Laurent

[BertSP]

Just received my Blue. I just want to verify my understanding of the jumpers for the ferrite antenna. If ferrite, I do NOT solder the jumpers? Solder only if using Loops.

[allsorts]

Correct.

Oh pooh "correct" is too short an answer!

[BertSP]

Correct.

Oh pooh "correct" is too short an answer!

My assembly on a Blue is finished. The (stupid) question I now have is how to properly connect the two ferrites to the amp. Is it +1 and Ground or +1 and -1.  The pattern will be the same for ferrite 2... My signals seem all to have a +0.04v bias to them, both on the E and H signals.  My station is 1691.  I do have the proper shielded cables.

[allsorts]

Loops or ferrites connect to the + and - terminals on the preamp.

A small positive offset of a similar size on all channels is a normal "feature". Mine is +30 mV +/- 10 mV.

Occasionally Ch1A will jump to -190 mV but this isn't reflected on the controller status pages. However I have just noticed that it is included in the strike data uploaded to Blitzortung.

[Alidigitaly]

Is there a maxi guide? :-)

Or a youtube version where all steps are shown to make each individual antenna?

[RichoAnd]

Is there a maxi guide? :-)

Or a youtube version where all steps are shown to make each individual antenna?

No!
I have made room for you to think for yourself
I wrote this explanation over 10 years ago, and nothing has changed
I have not touched my antenna for many years.
REMEMBER!
A long E-Field antenna gives you lots of signal, but also more noise.
The most important thing here is to keep this antenna as far away as possible from power lines, electric fences, lawn mowers with buried control cables, etc..
With a very long antenna you can get signals around the globe, but that is NOT what we want. We want a clean signal.
H-Field Antenna.
I have experimented a lot over the years, and have, among other things, very large loops in the attic. They are now used for ULF and VLF signals instead.
5-6 years ago (maybe more) I did an experiment with loop and E-field connected together. I got busy with other things, and the experiment just went on. Once the plastic bucket fell down, and I put it back up. It still works fine.
H-Antennas are for electromagnetic signals, and by their nature not so sensitive to E-fields. They don't have to be placed high, as long as they are far away from electric motors and old lawnmowers etc.
Ferrite antennas are best when they are shielded - There are some pictures somewhere with ribbon cable or brass or copper foil or any metal tube (slotted)
.... so just do some experiments to see what's best in your case.

/Richo

[Alidigitaly]

Is there a maxi guide? :-)

Or a youtube version where all steps are shown to make each individual antenna?

No!
I have made room for you to think for yourself 
I wrote this explanation over 10 years ago, and nothing has changed
I have not touched my antenna for many years.
REMEMBER!
A long E-Field antenna gives you lots of signal, but also more noise.
The most important thing here is to keep this antenna as far away as possible from power lines, electric fences, lawn mowers with buried control cables, etc..
With a very long antenna you can get signals around the globe, but that is NOT what we want. We want a clean signal.
H-Field Antenna.
I have experimented a lot over the years, and have, among other things, very large loops in the attic. They are now used for ULF and VLF signals instead.
5-6 years ago (maybe more) I did an experiment with loop and E-field connected together. I got busy with other things, and the experiment just went on. Once the plastic bucket fell down, and I put it back up. It still works fine.
H-Antennas are for electromagnetic signals, and by their nature not so sensitive to E-fields. They don't have to be placed high, as long as they are far away from electric motors and old lawnmowers etc.
Ferrite antennas are best when they are shielded - There are some pictures somewhere with ribbon cable or brass or copper foil or any metal tube (slotted)
.... so just do some experiments to see what's best in your case.

/Richo

Thank you! I love your clarity!

So it is basically a case of “figure it out yourself.” :-)

I find that unfortunate, because I am not an antenna expert and genuinely had no idea what I was doing. Experimenting felt risky because I was afraid of damaging the equipment. I prefer to build things correctly and according to the manual—but apparently there is no such manual.

I now understand that there is no one-size-fits-all solution, but some practical instructions would still be very helpful.

Anyway, I took the plunge and, with some help from ChatGPT, built an antenna.

And it works! :-) Wow, my first antenna ever!

For other newbies, here is my little project:

1. I bought 11 m of 2×0.75 mm² copper speaker wire.
2. I separated it into two individual wires.
3. I made a frame from three 80 cm wooden battens, crossing at the centre at 90°—like a Czech hedgehog or “anti-tank cross.”
4. I wound each wire three times around the frame, creating two loops at 90° to each other.
5. I connected one loop to H1+/H1− and the other to H2+/H2− on preamplifier PCB 23.1.
6. I left both solder jumpers open.
7. I connected the preamplifier to my System Blue Mini and left the controller on its automatic settings.

Both channels are working, with an almost identical noise floor of approximately 13–14 mVpp.

It may not be the most elegant antenna ever built, but it was cheap, simple, and it works!

I’m happy to be on board! In the future, I hope to create some practical how-to guides on this subject, because I feel there is a real gap in the available documentation.

[cutty]

So it is basically a case of “figure it out yourself.” :-)

Yeah, some background and competence comes in handy... you've not see the worst yet. 
If you'd give use your station number we could upgrade your forum access...

[Alidigitaly]

So it is basically a case of “figure it out yourself.” :-)

Yeah, some background and competence comes in handy... you've not see the worst yet. 
If you'd give use your station number we could upgrade your forum access...

:-)
It is 3304, but not given the activation yet.