[ / / / / / / / / ] [ b / n / boards ] [ operate / meta ] [ ]

/hamradio/ - Electronics

For the discussion of electronics, tinkering, radio, amateur radio, and related electromagnetic phenomena and communications.

Catalog

8chan Bitcoin address: 1NpQaXqmCBji6gfX8UgaQEmEstvVY7U32C
Click here to find out if your antivirus software sucks!
Name
Email
Subject
Comment *
File
* = required field[▶ Show post options & limits]
Confused? See the FAQ.
Embed
(replaces files and can be used instead)
Options
Password (For file and post deletion.)

Allowed file types:jpg, jpeg, gif, png, webm, mp4, pdf
Max filesize is 8 MB.
Max image dimensions are 10000 x 10000.
You may upload 5 per post.


File: 1429802910549.jpg (252.03 KB, 1200x1600, 3:4, ant_ham-radio_n7eo_klm-kt3….jpg)

 No.270

I've heard you can use HAM Radio in combination with certain software in order to send files between computers. What sort of software/hardware, and what kind of bandwidth are we talking about? Can it work for streaming video? Would the microwave bands provide high enough data transfer speeds?

 No.271

YouTube embed. Click thumbnail to play.

>Can it work for streaming video?

No, but there is Slow Scan TV.


 No.272

>>270

Idea 1:You could encode a file into audio data, use a normal 3.5mm headphone jack to a radio, tune in on both sides, transmit/record, then decode your data.

Idea 2: Break file into parts like a torrent does then checksum each part to make sure they aren't corrupt. Bittorentsync should be able to do this but I don't know how to tunnel LAN through radio.


 No.273

>>272

SLIP and CSLIP should allow you to tunnel internet trough a KISS TNC, or soundmodem (which looks like a TNC in KISS mode for the computer anyway).

Just be aware that running TCP/IP over AX.25 has tons of protocol overhead, so 1200baud or 9600baud are painfully slow.


 No.278

>>270

Not counting x.25 overhead your image would take 28minuts to transfer at 1200baud on packet.

http://www.calctool.org/CALC/prof/computing/transfer_time

Microwave would be better for streaming and such but your talking line of sight point to point with 2 dishes pointing at each other.


 No.281

File: 1430275497717.jpg (39.87 KB, 483x175, 69:25, 0337.jpg)

Data rate is determined by bandwidth, which is largely determined by frequency, and frequency determines range.

Long range = (relatively) low frequency = low bandwidth = low data rate.

High data rate = high bandwidth = (relatively) high frequency = short range.

This is why your WiFi runs at 2 or 5 gigahertz, transmits tens or hundreds of megabits per second, and barely leaves the house, while amateur packet radio can run at a few megahertz, transmits at a few tens or hundreds of baud and can cover the entire globe with the same power level.

Theoretically you could achieve almost any speed you wanted via amateur radio, you would just be constrained to line-of-site as speeds increased due to the required directivity of the antenna.

The Icom ID-1 has an ethernet port built in for up to 128 kilobit/s data, but it's designed for use with their proprietary DSTAR system so I'm not sure anybody is really using it at the moment.


 No.301


 No.314

>>281

With model rocketry getting cheaper each year, I'd wonder if some HAM's will try putting their own repeaters into orbit.

If so, that'd be another way to extend packet radio ranges.

>>301

Interdasting……


 No.315

>>314

Not going to happen. Very hard to do orbital insertion with solid fuel rockets. The japanese did it with their first satellites. But it is very hard for the hobbyist.

Balloons are the thing you want if you want to hoist up repeaters. But hams have few functional orbiting FM repeaters currently. and IIRC few whit different styled transponders.

Two geosynchronous transponders are under way. one for europe/africa/middle east region and one for usa.

This will be launched in 2016 http://www.amsat.org/?p=2523

Then there is a proposed "advanced microwave transponder" payload going up in 2017 on some USA satellite.

Some functioning satellites listed here:

http://oscar.dcarr.org/

SO-50 is at least working,




[Return][Go to top][Catalog][Post a Reply]
Delete Post [ ]
[]
[ / / / / / / / / ] [ b / n / boards ] [ operate / meta ] [ ]