Antenna thread

[Vipersan]

Completely ignoring the permittivity of polycarbonate............

http://www.m-ep.co.jp/en/pdf/product/iupi_nova/physicality_05.pdf

Not ignored CH ...just difficult to choose an alternative ..
Something has to support the Helix ..and polycarbonate seemed a good compromise...and since I'm using a cross config shouldn't mask too much element ..
A large portion of this project has to be guesswork...at least for me it does.
;)

 

[Vipersan]

Got the 60cm dish mounted outside my playroom window ....and have Ged (Digi247) popping by to get it as close to 15.6W as possible hopefully this afternoon ..
60cm ..may well be too small ...but since I already had it ..figured to worth giving a go ..
I am prepared to substitute a TD88 if need be ..but I can't keep adding dishes and p!ssing neighbours off ...so ...fingers crossed.

 

[Vipersan]

So ...had to at least try it ..even though it's not on a dish ...and the wrong polarity..
pointed roughly in the direction of Inmarsat at 15.6W ..
Indoors and behind glass ..
Of course this _could_ just be random PC noise ...?
but what I can tell you is ..
No LNA involved ..
It is directional ...
It does disappear when the antenna is disconnected from Airspy ..
It is roughly in the 1.5ghz range
So ...I'm assuming that the helical is at least 'tuned' to the right band..
here is a pic of the antenna balanced on the telescope angled upwards ....
..and a screen grab of ...errr ...some signal spike in the right region which is about 5db above the noise..
rgds
VS

 

[Vipersan]

Hmm ...LVDH ...
anyone ?
Ant Idea what the tick tick tick signal with perfect spscing that comes and goes at 1.415 ghz approx is ??
certainly is err regular ..like clockwork when present ...but then disappears for a few minutes before returning ...
Certainly is man made and not just a phantom noise signal ..
I thought GPS perhaps ??...but I assume that would be constant...
this isn't...?
here is a screen cap..
Seems to come in packets of 7 ticks ..then one miss ..then repeats..

 

[Analoguesat]

I am prepared to substitute a TD88 if need be ..but I can't keep adding dishes and p!ssing neighbours off ...so ...fingers crossed.

Why not? I do

 

[hvdh]

Hmm ...LVDH ...
anyone ?
Ant Idea what the tick tick tick signal with perfect spscing that comes and goes at 1.415 ghz approx is ??

That signal shouldn't be there, it is in the radio astronomy band 1400...1427 MHz where all man-made emissions are prohibited...
Hydrogen line is at 1420.4 MHz.

 

[Lazarus]

That signal shouldn't be there, it is in the radio astronomy band 1400...1427 MHz where all man-made emissions are prohibited...
Hydrogen line is at 1420.4 MHz.

Maybe VS has discovered a new Planet?

 

[PaulR]

Ant Idea what the tick tick tick signal with perfect spscing that comes and goes at 1.415 ghz approx is ??
certainly is err regular ..like clockwork when present ...but then disappears for a few minutes before returning ...
Certainly is man made and not just a phantom noise signal ..
I thought GPS perhaps ??...but I assume that would be constant...
this isn't...?
...
Seems to come in packets of 7 ticks ..then one miss ..then repeats..

You say it's man-made but can you be sure?

This is very reminiscent of the way that Penzias and Wilson were tasked with getting rid of the background hiss in the microwave band. They looked at all sorts of things, local emissions, faulty receivers, bird poo in the receiver horn until eventually they realised that it was coming from the sky - in fact it was extra terrestrial. They had discovered the background microwave radiation from the start of the universe in the big bang.

Could be a Nobel prize coming your way VS!

 

[Vipersan]

You say it's man-made but can you be sure?

This is very reminiscent of the way that Penzias and Wilson were tasked with getting rid of the background hiss in the microwave band. They looked at all sorts of things, local emissions, faulty receivers, bird poo in the receiver horn until eventually they realised that it was coming from the sky - in fact it was extra terrestrial. They had discovered the background microwave radiation from the start of the universe in the big bang.

Could be a Nobel prize coming your way VS!

Sadly I cannot find it again ...
DoH!! ...there goes my Nobel Prize ...
lol

Tried to decode the Primer ..
No compressed images of Hitler either ...
and Vega wasn't in ascendancy ...
Crap...

 

[Channel Hopper]

Sadly I cannot find it again ...
DoH!! ...there goes my Nobel Prize ...
lol

Tried to decode the Primer ..
No compressed images of Hitler either ...
and Vega wasn't in ascendancy ...
Crap...

Have you checked the cat's collar ?

 

[Vipersan]

Have you checked the cat's collar ?

bog standard leather collar ...no lectrics buddy ..
Peppa has been chipped though ..
Hmm..
the thick plottens ..

 

[Lazarus]

I've got your number.

You have a cat because of some mad notion its whiskers might have a role in your reception projects.

Innit.

 

[Vipersan]

I've got your number.

You have a cat because of some mad notion its whiskers might have a role in your reception projects.

Innit.

There is some truth in that G ...but not the main reason ..
I'm often to be found with my fingers up the cats A hole ...
When times are hard ...often it's worth checking if there is still money in the kitty ...???
I'll get me coat ..>>>>

 

[Vipersan]

Still waiting for various nuts n bolts etc ...but have now sufficient to mount the dish bracket to the backplate..
this is what it looks like so far ..
rgds
VS
...time for my friday soak in the tub..
;)

'scuse the mess ...I'll tidy up tomorrow..

 

[Lazarus]

Reminds me of one of those things you used to see at fetes, fairs and galas where you had to traverse a copper wire using a wire lollipop and every time contact was made a buzzer went off.

 

[Analoguesat]

Reminds me of one of those things you used to see at fetes, fairs and galas where you had to traverse a cooper wire using a wire lollipop and every time contact was made a buzzer went off.

If VS wires it up wrong it may well do that

 

[Vipersan]

Not a lot to aim for at 15W with a 60cm dish ...but am sure I'm damned close having locked ASDA FM @ 7.4db 11492 H ..
I'm guessing there isn't a lot more can be squeezed out of a 60cm ..
unless you know otherwise..
It isn't easy for me up ladders any longer ...and Ged hasn't paid me a visit as yet ..
..at least the sun is shining and nice weather for it ..lol

 

[Vipersan]

Itching to test the helix on the dish ..now pointing roughly at 15W ...
So ..since it wasn't too windy ..I braved the ladder again ..
There are impedance issues as I am conecting from 50 ohms to 75 ohms and back to 50 indoors ...and no LNA in citcuit as yet ..
But there is definately errr ...something on the waterfall ..
see for yourself ...
rgds
VS

 

[Vipersan]

Disappointing so far ...
There are definately data bursts in the right region ...but theoretically should be seeing at least 3 continuous 10.5k streams ...
Not bursts ...and certainly not a single burst stream ...
Adam manages to get all the Aero H channels ...using a 90cm PF indoors behind glass ..so I assume I should have a chance at least outdoors with a 60cm offset..
First problem is being sure I am actually pointing at Inmarsat 15.6W ..
Any ideas how I might achieve this ?
Getting 15W in Ku ...and nudging a little to the west may not be a sufficiently good method ..
rgds
...and gawd knows what that burst data is then ..but 'tis certainly strong but wont activate Jaero ..thats for sure..
Receiving AERO-H on L-Band with an RTL-SDR - rtl-sdr.com

 

[hvdh]

Never mind being 0.5° off, with a few tens degrees beamwidth!
Instead, no room left on your bigger dishes?