After you have made and tried various antennas and have comparaed their performance, do one more project: add an inline amplifier.
The amplifier greatly enhances range of every antenna.
To make inline amplifier work, you will also need a dc power supply (dc adaptor) and power inserter,
The amplifier, dc power supply & dc inserter each will cost from $5 to $15 depending on make and the seller.
Thanks for detailed info about your project.Its definately on the list
I already have an amp from my sat TV days, a couple of splitters laying around that I can repurpose for the injector & a few misc laptop PSUs which should be around the 15-18v mark.
I'm all set for things to do this long weekend
I'm looking at connecting the antenna & splitter directly to the r820t receiver with no coax feeder. Have you noticed any issues with frontend overload/the need for a saw filter in this configuration?
I'm running my receiver from a raspberry pi using dump1090 with default gain settings (not sure what they are)
So I've been meaning to upload some pictures but I've been lazy!
I've built both the dipole & pepsi-can antenna and had them running on the amp. So far it seems the dipole has a better range than the cantenna.
I'm waiting on a few more parts from ebay, then I'll be putting my raspberry pi, rtlsdr dongle and amp power injector into a waterproof box at the top of my tower (photos down the page). Hopefully this will yield a better maximum range.
Unsure yet how the rpi & dongle will go with temperatures at the top of the tower, especially in our 40'C summers.
My aim is to be able to receive ADSB aircraft from west of Port Lincoln on the Eyre Peninsula, which requires a 300km receive range. Currently the best I'm doing is about 200km which is just shy of the east of Port Lincoln.
Baseline range plot - e4000 tuner with magmount antenna, approx 2.5m above ground sitting on the gutter. Range is approx 160km.
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Baseline range plot with r820t tuner & magmount. Range increased slightly to.
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Construction of dipole & resulting range plot. Dipole elements in picture hadn't been cut to size yet.
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Construction of pepsi-can antenna (using a beer can) & resulting range plot.
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Receiver & injector - Using a old laptop power supply
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Antenna location - on the back of the house in a plastic bag, taped to a piece of bamboo.
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A picture of all my other antennas and radio tower. Tower has Amateur 2m & 70cm yagi. Chimney pole has 4x antennas for 2.4&5ghz WiFi-long distance community wireless network. Also a airband J-pole and a 2m/70cm J-pole.
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Thanks for looking
.....I've built both the dipole & pepsi-can antenna and had them running on the amp......
Your range is less than it should be with an amplifier and not very long coaxial cable.
The first & foremost limitation comes from the terrain. Even the best equipment cannot increase range beyond the limit set by terrain. Only antenna height can increase the range limit to some extent.
I have pltted the maximum range achieveable at your location with antenna height 20 feet above ground, Two range curves are plotted, the blue one for planes flying at 40,000 feet & orange one for planes flying at 20,000 feet,
You should be able to achieve this range. Your home is blocking signal in some directions with antenna at current height/location. When you will mount your antenna on the tower, above roof line of your home, range should increase to some extent.
Please see your Maximum achieveable Range plot based on your terrain & 20 ft antenna height.
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I have been lurking here for awhile, but tonight I assembled the parts I purchased on eBay to built my amplifier. Despite my horrible soldering skills, everything went together without a hitch. And, the moment of truth as I plugged in my wall wart didn't result in any blown fuses.
The result has been pleasant. My RTL1090 has gone from an average of 2-3 lights on the packet rate to an average of 4-5.
I have a DIY omni antenna around 25-feet in the air (it's the green one shown in the photos people post), but I do have a 5/8 vertical wave that seems to "pull in" more packets, but not the seemingly wider footprint of my current antenna. I will double-check it again tomorrow, as I switch them.
Overall, very pleased.
Nice work, very neat & crafty. Thanks for sharing the photos.Well, here they are... in all their glory.
Notice how I screwed the splitters to a piece of wood. It cleans up the project a bit, and it sits nicely on the window ledge.
The map shows how my antenna is pulling in signals from across the region. I understand my geography is VERY flat, so this may aid my attempts. I may swap out my current antenna for my 5/8 tomorrow, depending on the weather. Hope you like the photos...