Re: not receiving inmarsat C L-band data #aero

Paul Gulliver

I don't understand why your receive set up is failing, I'll take some of your points in order:

1) Bias T - have you physically checked the voltage is there - with a meter - it should be around 4 to 5 volts
2) if you added the NooElec  LNA it would have blocked the power to the patch - did you add a 2nd voltage supply to the patch? - a 2nd bias tee between the LNA and Patch
3) I don't understand your worries about a prime focus dish - an offset dish is perfectly ok, assuming you have the correct arm to attach the helix to it should be in focus.
In any case you should be getting some sort of signal without a dish.

As for my own setup, I like to experiment so I've built a patch antenna, and a helix antenna - both work ok without a dish. I've made two helix, one right hand for direct use and the other left hand for use with a dish.

The dongle is a RTL-SDR V3 with bias T (switchable using a simple batch file) if I want to add and amplifier.
Sorry, I have no knowledge on the Funcube - the website says software switchable so perhaps there is a command you can send to switch it on?



On 10/12/2018 at 09:50, Roland Fechter <fly-fechter@...> wrote:
first thank you very much for all your kind suggestions.
Re bias T use - yes my Funcube has use of bias T ticked - it sends I think 5 V ! - does it really ?
Even when used with a short cable and my English patch antenna - pointed towards SE - my SDRsharp does not detect any signals.
1545 and 1575.4 MHz GPS freq tried.- Sawband of Nooelec added no effect to be seen.
 Dutch RFham design LHCP feed not yet received.
I am afraid it will not be possible for me to attach it and center it correctly on my current 80cm Offset dish.
Alternative would be a small Prime Focus dish of up to 120cm where this feed could fit as it is designed for prime Focus dish use.
Helas - unable to find ANY prime Focus dish at all - if you know supplier kindly pass me its online address.
I resume:
Location of Inmarsat satellite processing L-band data not possible for me at all ! How did YOU succeed ?
Which antenna did YOU use ?
For Funcube users ;
Settings for activating Bias T  ?
I look forward to your comments.

Join to automatically receive all group messages.