Архив за Ноябрь, 2016

Sdr rtl вот такое Г высылают некоторые китайцы. не покупать!…

Sdr rtl вот такое Г высылают некоторые китайцы. не покупать!

Sdr rtl вот такое Г высылают некоторые китайцы. не покупать! (00:00:54)

Sdr rtl вот такое Г высылают некоторые китайцы. не покупать!

New posts: Outernet antenna and LNA at antenna

Nov 24, 2016

Been building antennas for Outernet use over the last couple of days, succeeded to get well over 3dB SNR required for downloads.

Easy homemade Outernet Antenna

A truly portable a cheap - less than $1 total cost - antenna.



Also did some more tests of the Pro Stick Plus - versus other receivers and with different antennas.

Enjoy.

Homebuilt Outernet Antenna 7+ dB SNR [00:01:04]

Building info here:
http://www.radioforeveryone.com/p/easy-antenna-for-outernet-l-band.html

All SDR

Авиационный приемник RadarBox

All SDR

SDRSharp в Linux

Homemade Outernet antenna receiving signals [00:00:52]

Full construction details on radioforeveryone.com.

The wait is over — Thumbnet N3 shipping

I've just got the following email from Wade from Thumbnet:

"Hello Akos.

I got your N3 production unit out yesterday.

(...)

Feel free to review, write and post anything you care to."

I've been drooling over the manufactuer images for a while, final product looks sweet:




I've also received more images:





Can't wait.

ADS-B: Pro Stick Plus vs LNA at antenna

Update Nov 13, 2016: added info to images due to comment.

Common wisdom is to place LNAs at the antenna.
Let's test a FlightAware's Pro Stick Plus against Premium dongles with LNA at the antenna, with long coax cable length.
Which setup gets more reports?

Test details



- Pro Stick Plus as the highest performance pure ADS-B receiver for $21, review here,
- rtl-sdr.com blog v.3 and Nooelec SMArt as top premium dongles available now, had same ADS-B performance in a previous test,
- Janilab LNA with external power, gain set to 19 dB, for $25 incl. worldwide shipping,
- two 45 feet / 15m RG 59 Mil-STD coax into splitter, Nooelec pigtails and adapters,
- two Raspberry Pi 3 from a ModMyPi Starter Kit, so identical back-end computing, system variance less than 2%.
Antenna is a half-wave telescopic commonly available with dongle bundles, on a metal tin. Normally, I get around 20,000 position reports with this antenna and short coax lengths.
No user involvement, and no gain adjustment in PiAware.

Results

rtl-sdr.com v.3 used on Day 1, Nooelec SMArt on Day 2. Totals indicated.







Polar Plots:




Frankly, I'm just as surprised as you are, as I've only seen the results when double-checked which IP address belongs to which receiver combo.
15.17% percent more position reports with a Pro Stick Plus, which costs half as much as a premium dongle and preamp. Granted, it will be pretty much unusable for general use due to filtering, but the same 1090 MHz filter also does wonders for ADS-B reception.
Significantly less position reports than usual; other FA feeders in my area did not experience such a downturn, so the only explanation is long coax length. Minimize coax length for best signal, or completely eliminate it with direct connections.

It's only one test


Your location, preamp, antenna, cable and retina is different from mine. The "LNA at the antenna" mantra comes up so often that I wanted to see what happens for ADS-B use. That's all.
The fact is that a receiver built for a specific task with a preamp and filter, costing $21, beat a combo built for general use costing $46. Adding a filter for $20 might narrow the performance gap, but spending $66 when the same job can be done for $21 seems a bit stupid. If you can run coax to a remote location and mount an antenna there, you should be able to run Ethernet cable and mount Pi3 with PoE at the antenna. Ethernet cable is so much cheaper than coax.

Unavoidable

I'm writing posts at the moment, and concurrently testing lots of equipment.
This blog is supported by the following manufacturers:
- Nooelec,
- rtl-sdr.com,
- Adam,
- FlightAware,
- Outernet,
- Thumbnet,
- ebay seller novakx,
- ebay seller Janilab.

Some of the makers above offer similar products, so comparisons are unavoidable. And necessary. And the purpose of this blog.
I can't help it, so I'll tread on quite a few toes in the near future.

As a teaser:


- Outernet kit is great fun, unbelievably easy to use,
- rtl-sdr.com broadcast FM filter works quite well,
- Pro Stick Plus is astonishing, but only for ADS-B,
- LNA4ALL has a competitor from novakx, 
- FlightAware antenna still beats everything else, at a cost and size,
- homemade ADS-B antennas are great.

Plus many more, I'll try to catch up with posting, doing justice takes time. Watch this space, follow on twitter @rtlsdr4everyone for news.

Stay tuned, 

Akos


Обновлен File Player.

Исправлен для совместимости с последней версией SDR# 1489.

Скачать...

Обсудить
Перевод
Рубрики
Ноябрь 2016
Пн Вт Ср Чт Пт Сб Вс
« Окт   Дек »
 123456
78910111213
14151617181920
21222324252627
282930