Adriatic Sea Reception Report

Good news to report. At 1730 UTC 2 Oct at 44 deg 4.67’ N - - 15 deg 15.04’ E off the coast of Zadar, Croatia, on a course of 127 deg (true) at 9.5 knots, strong SNRs of 2-3 db with packets downloading and Sig State of 3 were achieved on Alphasat 25 deg E under an overcast sky. Sea state was calm.

As the coarse of the ship changed, I had to readjust the antenna. With the antenna’s 40 degree beam width, adjustments were not supper critical, and were easy to manage. Ken

What happens when you lay the Lantern down flat and the antenna is pointing straight up?

Laying antenna flat results in no signal:

Aimed at Alphasat 25 deg E, I have a low elevation of 39 deg and magnetic bearing of 168 deg in Split Harbor, Croatia, at Lat 48 deg 30 min N, Long 16 deg 26.5 min E. Getting good strong signals with SNRs no higher than 3 dB: During rain, I get no signals (and have to pull the Lantern inside as I have no waterproof cover). During periods of heavy overcast signal levels dip below SNR of 1 dB, so I can’t close the link.

We travel in late evening, so keeping an eye on the Lantern is not practical for long periods as I like to sleep. Ken

Marine Reception

Some other interesting event related to marine reception have occurred. Since we are farther North than usual off the Croatian coast, I have to set the Lantern at a pretty steep angle. As a result of the heavy winds sometime occurring, the Lantern blows over in mid reception really killing the download :kissing:

Also, while at anchor with anchor swing, the Lantern requires more attention to keep pointed than during a straight course passage. I suspect at lower latitudes, Syed is right about the Lantern being able to close the link when laying flat (but not here).

Has anyone tried this in the Caribbean yet? Ken

Ken well done on your experiments.

I think a Helical L-Band antenna of the type supplied by Inmarsat to ships would solve your problem.

If you have a chance to get near a machine or electronics shop, or even better a keen HAM radio guy, make a “right hand polarized” Helical wire coil and put it on some foil or tin base and connect it to some 50 Ohm Coax and into your rtl dongle.

It should have a 180 degree semi hemispherical coverage. (ps. I am pretty sure Outernet Signal is RHP)

Here in the tropics laying flat I get 4db SNR and directional pointed at the satelite 9-10 sdr.

@zoltan Can you upload some pictures and directions for your RHCP helical?

Fractal Antenna

I’m going to try Seasalt’s suggestion when I get back home to my work bench.

I also think use of fractal technology may have something to offer.

I have an amplified omni directional UHF fractal antenna I use in Maryland to receive off the air TV stations. It works just as well as an amplified directional UHF yagi, so I’m thinking taking it a step up to L-band. Ken

rxos 3.0 Reception

No signal for the day on Alphsat 25 deg E at Dubrovnik, Croatia, at anchor Lat 42 d 38.5’ N Long 18 d 7.2’E.

At 1334 UTC 8 Oct skies are clear, but no signal:

Are there any other confirmations on Alphasat 25 d E using rxos 3.0? Ken

Yes, we have two confirmed receivers on 25E.

@Syed uploading some old pictures from a really basic helical design, used this on Inmarsat safety reception successfully. No time yet to test it on Outernet but should work for sure.
I’ve used this calculator that time:
For the wire used a spray can with the very similar diameter to bend the copper wire properly

For proper use some plastic holder tube would mandatory as you can see the wire cannot self support itself…

Zoltan, your look angle appears to put you pretty far North (or South). How does your antenna perform laying flat at your latitude? Ken

Ken, that’s an old picture, that time using for Inmarsat recepetion from EU, Hungary. To be honest not played with this too much, more with the patch antenna as that’s more compact.