Messages

1

FPV / FPV in IRL

« on: May 19, 2011, 21:34:28 PM »

There was a teletext encoder available for hobbiests but the company that sold it no longer does it.

With digital transmission, which I am working on, it is theoretically possible, but the off the shelf units just allow setting of station name etc.

There is some guys in the UK working on PC based transmissions where every aspect can be varied, and they hope to use it for one way data transmission.

Your best best would be to use a seperate 433.92Mhz serial modem to send the data. These are dirt cheap and easy to interface with. Some have built in error correction and are fast and good. It's what I would use.

Dan

2

FPV / Radio and video sending

« on: May 16, 2011, 18:44:49 PM »

Hi,

I have read with interest the messages so far. I have an amateur radio licence and I have been involved in sending TV pictures for 10 years.

From a techical point of view

1249Mhz transmitters are illegal in Ireland and we use 1240 -1300 (and received up to 1320) in Ireland so you will interfere with us! We report interference and can track down messers. We have already has to report and remove illegal commercial security cameras from our allocation.

MPT1349 (probably comreg typo) is actually on 1394Mhz and it seems to be exempt up to 500mW (this is a lot of power for a model aircraft)

See:
http://www.sourcesecurity.com/docs/fullspec/ACFA94.pdf

and
http://www.icecom.is/gogn/18931003.pdf


Generally I would not really advise it for your use as there may be high power users in every city which could cause interference. Generally the 5.8GHz stuff is better but is more expensive. A good camera is very important also.

We have a website with info (not 100% up to date)
http://www.iatc.ie

and there are people involved in Dublin, Cavan, Waterford and Cork. We mainly have equipment at the top of mountains which listens for a TV signal, then re-broadcasts this on a different channel.

For your use I would also suggest using directional receive aerials on the ground end as these are perfectly legal and can help the signal. The down side is someone needs to point the thing.

I am available to offer advice, give help and demo gear if needed. There is lots of good and bad gear out there so ask somone for advice. I aI (along with others) are working on text overlay on the video so you can ddiaply things like altidue, position (from GPS) and time/date etx. We are also conidering auutomous flight in the future (pilotless) I live in Bray Co Wicklow, so we can meet.

We have very high power transmitters and very, very sensitive receivers. I am also working on digital TV transmitters. These would be more useful for semi professional use or from a full size glider to ground. We can use them "aeronautical mobile" and you will hear a hot air balloon on our frequencies from time to time. The legal aspect is to stop interference with other users and your own aircrafts equipment.

Regarding cost we normally build our own stuff, or modify off the shelf gear. It's only a hobby after all.

Dan 087-7731120
Bray, Co Wicklow