Antenna thread

[Vipersan]

So ..I'm starting a new thread about Antennas (various)...which can cover a multitude of possibilities but am hoping that info relating to antenna designs like the 137mhz QFH etc will find it's way here ..
So build designs ...plans...and just general info and discussion..

Here is a patch antenna I have already built for 2.4ghz ...circular polarised ..
It works very well but not really what I was after ..as I want to now build a patch antenna for L band ..
I have listened to Adam Alicajic ...as best I could ..and hopefully I now have the correct dimensions from his description ..
This will be RHCP but can be made LHCP if need be ..

This guy obviously knows his stuff ..
I'm waiting for some brass sheet for the build ..but will post photos when built..
in the meantime here is the smaller 2.4ghz patch..
rgds
VS

also upped the rough dimensions of the L band patch..

 

[Lazarus]

Ku Band antenna for strong Satellites

 

[Channel Hopper]

All antenna designs used for S-band, 13cm or 23 cm bands can be adapted without difficulty for use on 2.4 GHz.

 

[Vipersan]

So ..this afternoon I have been mostly Making a simple 3 element Vertically polarised ..omni directional collinear antenna for 1090 mhz
Not tried it yet as I have only just completed it ..
The ground plane being cut from galvanized steel 13cm diameter ...

..the loops are just right at 4cm length if wrapped around an AAA battery.
Here is the plan ..and a photo .
rgds
VS

 

[Vipersan]

So ..this afternoon I have been mostly Making a simple 3 element Vertically polarised ..omni directional collinear antenna for 1090 mhz
Not tried it yet as I have only just completed it ..
The ground plane being cut from galvanized steel 13cm diameter ...

..the loops are just right at 4cm length if wrapped around an AAA battery.
Here is the plan ..and a photoView attachment 92368 View attachment 92369 .
rgds
VS

Gonna have to make another antenna to test ...
I had misunderstood ..the loop size should be 40mm.....diameter..
I wrongly assumed 40mm length of wire for the loops..
More work to do..
;)
fun this aint it..
lol

 

[Vipersan]

No proof as yet ..but this looks like what I'm after..

 

[Vipersan]

So ...the antenna is working well but you wanna put it outside ??
At the mercy of the wind and rain ..
Weather proofing ...but how ...on the cheap..
Well ..I had a good think about this one ...but couldn't find any plumbing that was suitable ...so what to use ?
Thin walled plastic and the right length and diameter..
Then I realised why I dont throw anything that might be repurposed away..
Used sealant tubes ..
Perfik ...but not long enough...
Diameter wise ..a gift..
but what about 2 end to end ?
that would do it ..
but they would need joining ..
Doh ..
silly me the plastic plunger inside is a perfect fit ...and only one is needed ..
The other can remain fully depressed and sealing the open nozzle end..
The other can be removed as you have to hacksaw it open anyway to get a tube..
just make sure you dont cut into it..
Pop it out ...remove the middle of the plunger ..and you have a jointing collar..
Nice ..
Here is one I prepared earlier ...and yes ..one of those tubes has already been rubbed clean of it's content advertizing...
the other will be done presently..
So ..there it is ..the wickes weather sealant antenna ..
nice..


...Now to make a start on Tracey Island ...
..where did I put my B P Badge ?????

 

[Vipersan]

I'm Impatient as hell ...and hate waiting for stuff that has to cure ..
Here are some pics of the weatherproofing in progress ..
The bottom ring or container forming a sealed socket for the tubes is a Hartleys Jelly pot ..cut to size and epoxied to the roughed up galvanized ground plane ..
The bottom tube temporarily fitted and latex rubber poured in to make the seal...
Sadly I have at least an hour to wait for the curing ..
doh!

btw ..to increase the gain of this antenna ..simply add more 130mm sections and loops..
I guess there is a practical limit to this beyond which there is little gain advantage ..but worth keeping in mind..
I'll start saving more sealant tubes ..lol

 

[Vipersan]

Scuse the mess ...but thats it really ..
rgds
VS

 

[Vipersan]

So ..I've had another ...possibly silly idea ..
Was cruising Ebay ...and spotted a solar chargeable battery pack for £3.50 delivered ..
Well I had to have one at that price ...
This may or may not work ...but since the LNA needs to be as close as possible to the antenna ..and the LNA needs a localised 5 volt supply ...and I want the Antenna located outside at gutter height ...
I figured this may well be a suitable power supply for the LNA ..
..and will keep itself topped up in daylight hours ...and spew out 5 volts at about 500 ma ..
The unit is waterproof ..so may well be the answer..
..and a helluva cheaper than a Bias Tee ...which would allow DC injection into the coax indoors.
I'll keep you posted .
rgds
VS

 

[s-band]

..and a helluva cheaper than a Bias Tee ...which woukd allow DC injection into the coax indoors.

Antenna looks good. Cheap 1090 bias tee. See pic - left to right:
100p DC block, RF out on thin semi-rigid, 120R (probably because that was amongst the bench detritus) with leads used as inductors, 220p chip to ground, 1000p feedthrough on tin box, 0.1u to ground. Ignore the sloppy construction technique!

 

[Vipersan]

Thanks for the Bias Tee design S-Band ..
As for my antenna ..
More Tweaking ...
How can I make it stand up ...yet have room to fit the LNA etc ...and still be sealable against the weather ..
Enter ..another item from the scrap plastics bin ..
An empty CD spindle case with twist lock ..
Perfil diameter ..and once the spindle was cut out ...provided a nice access point to the BNC connector ..
here are a couple of photos..

 

[Channel Hopper]

Used sealant tubes ..
Perfik ...but not long enough...
Diameter wise ..a gift..

...Now to make a start on Tracey Island ...
..where did I put my B P Badge ?????

Except the type of plastic has a hi permittivity so you may find some odd effects on signals that are supposed to be coming in linearly polarised.

 

[Vipersan]

Except the type of plastic has a hi permittivity so you may find some odd effects on signals that are supposed to be coming in linearly polarised.

Well it appears to be working ok -ish atm ...even without an LNA I'm able to track planes up as far as the lake district and over wales and down as far as Peterborough ..
Antenna just hung out of my playroom window currently..
I guess better plastics could be used ...
any suggestions CH ...about the same diameter ?

I do seem to draw a blank to the East ..
Guess the penines are in the way ..
lol
..any one fancy shifting 'em ?
rgds
VS

 

[Channel Hopper]

I guess better plastics could be used ...
any suggestions CH ...about the same diameter ?

I'm not the one that should comment on your girth......

 

[Vipersan]

Popped the Antenna outside on an old mop stale ..
Yes I even keep those ..lol
Bit of a lash up ..but working just fine .
I have replaced the plastic CD spindle cover with a shorter one for now ...as I dont need the extra space for the LNA as yet ...
The deeper one is easily swapped back when I fit the LNA.
rgds
VS

 

[Llew]

The deeper one is easily swapped back when I fit the LNA.
rgds
VSView attachment 92474

If you can VS, can you give us a comparison on performance between LNA and No LNA when you fit it?

 

[Vipersan]

Managed to get some 50 mm ABS plasic pipe today to complement the 40mm length I got a week agao ..
Hopefully got all I need now to build the 1090 mkII ...which will be a 12 element version of the short antenna I already made
Due to the nature of the copper wire build (not coax) ...it will need to be structurally supported ..so will be wound on an inner 40mm core sleeve ..and inserted inside a 50 mm outer sleeve for weatherproofing ..
Photos to follow later ..
rgds
VS

 

[Llew]

Mine had four extra elements added, now a 12-element coax collinear. An LNA is on its way, so I can test with it in and out of circuit.

 

[Vipersan]

So ..I wuz robbed ...
This antenna is made ..not from wire ..but 2.5mm capillary copper tube ..but the 12 element came up a couple of cm short ...
I ordered enough tube to do the job ..but they short changed me ..
Not to worry I'll just sweat a little copper wire stump in the end of the last element..
So ..still needs a bit of teasing into shape then taping to stop movement ..
but here are 3 photos ..
a ) the collinear wound around the 40mm centre pipe ..
b) partially inserted into it's outer 50mm sleeve ..
..and C) just to show the nice end stop weatherproofing cap I got ..
It's a start..
lol