DIY Inmarsat Antenna

[RFI-EMI-GUY]

Excellent job. I actually bought and installed a tower and UHF & VHF antennas for AMSAT and AO-40 THEN IT CRASHED. Bummer

Well that sucks.

This helical construction technique is pretty rugged and forgiving . I had it range tested and it was within 1/2 dB of the dBd spec for a 12T and the test was down at 1296 MHz not where I designed at about 1550 MHz.

 

[Your_account]

Not for WiFi, AO-40 mode LS

I mean the Freqs.

 

[RFI-EMI-GUY]

Amateur satelllite S band uses the lower portion of the 2.4 GHz band that happens to be shared with WiFi. The white antenna was most definately made for amateur satelllite band, as a dish feed.

 

[ab5r]

RFI-EMI-GUY: FYI Using a Helical Antenna Calculator online, your 12.5 turn antenna had 15 dBi gain and a 16 turn would only have raised it to 16.8 dBi.

Thanks for the help.

 

[Your_account]

So Wifi run on:
2400,000 MHz - 2450,000 MHz

Radio Amateurs:
2304,000 MHz - 2310,000 MHz
2320,000 MHz - 2322,000 MHz
2400,000 MHz - 2450,000 MHz

 

[Lawman51]

Double Crossed Dipole for WX sat reception.

Hey guys was just on looking to see if anyone had a better mouse trap for the Polar sats for Wx monitoring...saw this thread and thought I would put in what seems to be a pretty good and easy build for these birds. Here is a link to the article I found on the one I am going to take a crack at. http://www.qsl.net/py4zbz/DCA.pdf there is a picture of the final product on the article and if you google for double crossed dipole you can find more pics and youtube has 1 or 2 builds by guys in europe mostly that have made them.

 

[rwgast]

I regularly monitor Iridium and inmarsat, using SDRs. I either use an RTL dongle with a few pre-amps or an AirSpy mini (99 bucks 100db noise floor) and one LNA. I use a homemade patch antenna. They are super simple here is a video about making a patch for inmarst, also wide enough to pick up iridium and decode pages.

Building and Testing an L-Band Patch antenna for Inmarsat-C Reception - rtl-sdr.com

here is my very humble set up, patch should give you 6-9db

 

[thewrench002]

here is my build.. and it works very good... made from a slinky... 20 turns with 20db amp.. getting good reception on 54w...

 

[kayn1n32008]

So Wifi run on:
2400,000 MHz - 2450,000 MHz

Radio Amateurs:
2304,000 MHz - 2310,000 MHz
2320,000 MHz - 2322,000 MHz
2400,000 MHz - 2450,000 MHz

Amateur satelllite S band uses the lower portion of the 2.4 GHz band that happens to be shared with WiFi. The white antenna was most definately made for amateur satelllite band, as a dish feed.

Remember guys, You are on different continents, operating in different ITU regions, under different governments that likely have different band plans in use.

 

[Your_account]

Here in Austria (and Europe?!) Radio Amateur operate there own Wifi Network on the normal Wifi Network freq but with an huge output power.

 

[RFI-EMI-GUY]

here is my build.. and it works very good... made from a slinky... 20 turns with 20db amp.. getting good reception on 54w...

What size pipe are you using, do you have a closeup of the attachment of the slinky and the feed point?

Sent from my SM-T350 using Tapatalk

 

[thewrench002]

the pipe is a 2 3/8 OD .pvc.
used a piece of wide window foam 5/8 or 3/4 to help hold the coils in place
slinky 2 3/4 cut to 20 1/4 turns..
Antenas - Helix - Javascript on-line calculator
change the design freq to 1550.
change the number of turns to 20
14" pizza pan
20db tv cable amp blue dongle and jaero and hdsdr software rg6 cable feed from antenna to computer area.....
bulkhead sma connector
SMA female jack chassis panel mount 4 hole solder connector; US stock; fast ship | eBay

1/2 plywood and some scrap 2x4..

I'm building a 26 turn to replace the one i have now due to some snow/ ice damage should be up in the next few weeks..

 

[thewrench002]

here are some of the pics.

 

[thewrench002]

this is what i'm getting this morning... off 54w .

 

[SDRPlayer]

Thanks for posting the extra pics John. This will be my next build so i can compare it with the patch + dish setup i'm running at the moment.

 

[kb4cvn]

<snip>

.... slinky 2 3/4 cut to 20 1/4 turns..

<snip>

Anything special to solder to the Slinky? Or, will standard solder, flux, etc. work?

 

[Your_account]

omg what kind of pipe is this?
In my "local" Store the have just pipes who are ~2mm thick.

 

[krokus]

Hey guys was just on looking to see if anyone had a better mouse trap for the Polar sats for Wx monitoring...

When I lived in Australia, one of the magazines there had a nice Lindenblad design, in an article by Tom Moffat, VK6TM.

Sent via Tapatalk

 

[thewrench002]

Anything special to solder to the Slinky? Or, will standard solder, flux, etc. work?

standard solder/ flux will work. I didn't do a 1/4 match on this one but you will need it.... do about 1/4 -3/8th wide on it.. my new one has a good match.

 

[thewrench002]

omg what kind of pipe is this?
In my "local" Store the have just pipes who are ~2mm thick.

schedule 40 plumbing/ drain