All posts for the month July, 2016


Mast head mount of the rtl-dongle gives low transmission line loss


Weather proofing of the receiver. Small plastic bag inside, bag open towards the lower side so any condensation can escape, secured with duct tape. This is going to survive heavy winter storms, no problem. The problem is the radiation of the Sun killing the plastics, so there will be some duct tape maintenance.



Raspberry pi 3


5dBi Antenna erected on the roof where I work.


Receiver range: receiver has not been running for many days yet, but so far It show coverage about expected. Light area: new receiver @ work. Dark area is my first receiver @ home. Rings @ 20 nautical mile.

Receivers are feeding the flightradar24 and planefinder networks. If you know about anyone else interesting in a data feed, please let me know.


After the antenna work I did in my previous post, my GPSDO MKII had stopped working.
Reason was that I had been a little too rough with the small coax going to the rooftop GPS antenna.
The coax had shorted and this being an active antenna the RF-choke on the Jupiter GPS board feeding the antenna with 5VDC was fried. Having no idea on what value the original inductor has I had to substitute it with something, I chose a 33nH inductor with a self-resonate frequency around 1.7GHz.

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Jupiter TU30-D140 GPS board


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GPSDO working again.


Couple of months ago high wind gusts bent a support tube in my tower.
Well, yesterday was repair day. Here are some photos.

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Photo taken earlier showing a bent support tube.


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Winch in place, getting ready to lower.


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Antenna on its way down.


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Faulty support tube removed.


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Not straight.


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On its way up again.


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improvements: Support tube is now made of steel, before it was of aluminum. Also, notice the second support bearing in the middle. Hopefully this improvements will make it hold.