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  #16  
Old 09-01-2016, 07:52 PM
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Will be interesting, but I suspect that the channel width will be a serious problem on a standard set... wonder what you will see.

I would suggest getting on a busy repeater and asking around... likely you will find somebody that knows all about these transmissions.

jr

Last edited by jr_tech; 09-01-2016 at 07:56 PM.
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  #17  
Old 09-01-2016, 08:35 PM
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Quote:
Originally Posted by jr_tech View Post
Will be interesting, but I suspect that the channel width will be a serious problem on a standard set... wonder what you will see.

I would suggest getting on a busy repeater and asking around... likely you will find somebody that knows all about these transmissions.

jr
I'll do that tomorrow when I'm not buzzed from beer. I have a sailors mouth when I drink, best I not get on the air.
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  #18  
Old 09-02-2016, 04:28 PM
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What would ham radio enthusiasts want with video transmission?

I picture it as being like YouTube for old people.
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  #19  
Old 09-02-2016, 04:45 PM
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I'd watch it.

And I ain't old, and am already interested in this.
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  #20  
Old 09-03-2016, 12:41 AM
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A little help for a non-ham who is getting hit on my wireless cams at my ballpark. I looked farther down in the AARL list and found 5 Centimeters (5650.0-5925.0 MHz) which is in the unlicensed space my cams operate at. We are not broadcast so we cannot get a licensed space.

Occasionally I will get a pulsing (every 4 seconds or so) carrier that hits my rxs. At first I thought it was airport terminal radar but it comes and goes and they are lower anyway. My rx units can show me the spectrum on any given channel I use and I can see the pulse but have no idea what it is. Could it be something from the chart? I operate on 12 possible channels between 5700 and 5975. 25 meg per channel for HD-SDI video and audio. The pulse seems to cross several channels at a time.

Is this an unlicensed space for hams also? Mystified here.

If this needs a new thread please proceed. Dave A
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  #21  
Old 09-03-2016, 12:56 AM
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If I'm reading this page correctly
https://en.wikipedia.org/wiki/U-NII

the table "5 GHz (802.11a/h/j/n)" says frequencies in this range are approved for 5 GHz wifi (your application), which says to me that someone else may be using it for a purpose other than your cameras. What that would be is hard to guess, but a regular pulsing sounds like maybe some sort of wireless link keep-alive. I once had a video repeater that shared the band with my cordless phone (2 Ghz? 2.5 GHz? don't remember now), and the phone would produce a repeating pulse in the video, making the video useless.
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Last edited by old_tv_nut; 09-03-2016 at 01:03 AM.
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  #22  
Old 09-03-2016, 01:02 AM
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Wayne...I looked at that too. Sysco has a warehouse near me and they do use 5gig wifi. Amazingly they are 2000' away and the signal is strong here. I think 5gig can have a higher tx power. I can see it on my wifi sniffer on my phone. But they are 24/7 and this comes and goes and the signal is wide enough to cover several channels at 25meg each.
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  #23  
Old 09-03-2016, 12:56 PM
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New wide channels in that range?

http://www.nhtsa.gov/DOT/NHTSA/NVS/P...(Fessmann).pdf

jr
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  #24  
Old 09-05-2016, 09:50 PM
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Originally Posted by lnx64 View Post
I just didn't know hams were using ATSC now. I thought they still used NTSC.
I am a long-time operator of TV over ham radio (ATV, amateur television). One of the joys of ham radio is that we are not limited to specific standards for most of our transmissions, so in the case of TV signals, hams have used NTSC (AM-mode), as well as FM-mode NTSC, and several digital modes. ATSC is pretty rare in the ATV world, partly because transmitting equipment is expensive and/or hard to obtain. Other digital modes (DVB-S, DVB-T, even QAM "digital cable" mode but put on the air) are more common.

If that 12-MHz ATSC signal was indeed an ATV station, the bandwidth was probably not intentional; it may be a type of intermodulation problem that happens in the station's amplifier(s).
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  #25  
Old 09-05-2016, 09:57 PM
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Quote:
Originally Posted by MRX37 View Post
What would ham radio enthusiasts want with video transmission?

I picture it as being like YouTube for old people.
I had to laugh at that comment! (-:

ATV operators do things such as relaying video from a disaster site to an emergency operations center, or behind-the-scenes activity from the Rose Bowl parade. We also just show off our latest projects (such as when I linked my own signal into my restored RCA 8TS30, then pointed a camera at it on the air), or scenes of our ham stations, cats in the house, have "tie-dye shirt nights" and many other activities. Lots of fun.
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  #26  
Old 09-05-2016, 10:58 PM
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Originally Posted by ChrisW6ATV View Post
I am a long-time operator of TV over ham radio (ATV, amateur television). One of the joys of ham radio is that we are not limited to specific standards for most of our transmissions, so in the case of TV signals, hams have used NTSC (AM-mode), as well as FM-mode NTSC, and several digital modes. ATSC is pretty rare in the ATV world, partly because transmitting equipment is expensive and/or hard to obtain. Other digital modes (DVB-S, DVB-T, even QAM "digital cable" mode but put on the air) are more common.

If that 12-MHz ATSC signal was indeed an ATV station, the bandwidth was probably not intentional; it may be a type of intermodulation problem that happens in the station's amplifier(s).
Yea the most I've done is AM mode NTSC at 70cm, because I can pick it up on any CATV ready set in CATV mode.

I actually didn't even know an FM mode existed for NTSC, now you have me more interested than ATSC, because I might be able to transmit this. *goes to research this*
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  #27  
Old 09-07-2016, 09:02 PM
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FM TV can look much nicer than AM NTSC, and there are inexpensive synthesized transmitter and receiver boards available from a Web site called hampubs.com (under $100 each if I remember). They operate on the 900 MHz and higher bands; FM TV is too wide a signal to be used on the lower-frequency ham bands.

Also, when you need an amplifier for FM TV, any "class C" one will work fine, so things are less picky than when setting up an AM ATV station.
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  #28  
Old 09-07-2016, 09:22 PM
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FM video is used for videotape, like that used in VCRs. Ham FM video might use chips intended for converting analog baseband video to FM to the tape head, and from the tape head back to analog baseband video.
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  #29  
Old 10-31-2016, 12:50 AM
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I would think as a ham, we would naturally gravitate to DVB-S over 1.2 gig since all it takes is a fta satellite receiver and a pre-amp on the antenna, plus a lot of European hams are working on modulators, amps, etc.


It won't take long for DVB-ATV or some other digital format to come to prominence.
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  #30  
Old 11-28-2016, 05:14 PM
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Indeed, DVB-S is being used for Digital ATV on the 23cm band (1240-1300 MHz) exactly as you described. No preamplifier needed, even, with the newer DVB ("MPEG FTA") satellite-TV tuners.
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