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VSAT technology and installation >> iDirect Forum: hubs and terminals >> RF over Fiber Optic
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Message started by saiahmed on May 31st, 2010 at 5:49am

Title: RF over Fiber Optic
Post by saiahmed on May 31st, 2010 at 5:49am
Any one using RF to FO conversion for a VSAT hub (specially iDirect). Please share the experience.

Which product is being using for conversion? What issues have been faced..??

Title: Re: RF over Fiber Optic
Post by dot on May 31st, 2010 at 8:41am
Have a look at this post from a short while back https://www.satsig.net/cgi-bin/yabb/YaBB.pl?board=idirect;action=display;num=1267071429;start=4#4

Title: Re: RF over Fiber Optic
Post by saiahmed on May 31st, 2010 at 9:01am
I have read that discussion. Different people have suggested different products.

Actually, I want to know if someone is using any of these products. I want to know about the experience and issues (if any).


Title: Re: RF over Fiber Optic
Post by wbailey on Jun 1st, 2010 at 9:34pm
We're using RF over Fiber right now. It works fine.. balance your levels wisely though, as that's the hardest part. And do L-Band over Fiber .. not native C/Ku/Ka/X..

Title: Re: RF over Fiber Optic
Post by Oasis Networks on Jun 2nd, 2010 at 8:58am
I agree with the above.

Again - I have limited experience - just installed couple of foxcom systems.

The main issue to to calibrate the power at the beginning, but then it works fine.

As Eric explained in the original post, the converter is analogue, therefore, like any analogue device, calibrating of input and output levels demands some patiance and care, thats all.
You will have to calibrate first the input signal (from the LNB to the ODU converter for downlink; from the modem to the IDU converter for the uplink). Check the level of the input signal using a voltmeter and follow the manufacturere recomendations.
Then you will have to calibrate the output level of the converter (converter ODU for uplink and converter IDU for downlink). You may need to repeat those stages several times untill you will get good signal, which is strong enough but not saturated.

Another hint: Temporaly put your modem next to the dish, and check the level of signal you get and note it down. Do the same with the transmittion: Transmit when the modem is connected locally and ask how the other side receive the signal (or check it yourself if you can), and then introduce the fibre converter to the system. The previous test will allow you to have some reference about the performance you should target when calibrating the system.

And again..lot of patiance.

Title: Re: RF over Fiber Optic
Post by saiahmed on Jun 7th, 2010 at 6:35am
Thanks everybody for their replies. I will update when the system is installed.

Title: Re: RF over Fiber Optic
Post by yazzdan on Jun 11th, 2010 at 2:03pm
Thanks Dot for such a nice sharing

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