Home |
Search |
Today's Posts |
#1
![]() |
|||
|
|||
![]()
On Friday's edition of Allan Weiner Worldwide, Michael Ketter announced that
WBCQ's 5.105 MHz station would transmit its ID in SSTV at the top of the hour during "Area 51", Sunday nights from 6 to midnight Eastern US time. |
#2
![]() |
|||
|
|||
![]()
OK, so what the heck is SSTV s ?
"Jim Shaffer, Jr." wrote in message ... On Friday's edition of Allan Weiner Worldwide, Michael Ketter announced that WBCQ's 5.105 MHz station would transmit its ID in SSTV at the top of the hour during "Area 51", Sunday nights from 6 to midnight Eastern US time. |
#3
![]() |
|||
|
|||
![]()
What's SSTV please? Don't think we use it here in the UK. Possibly Slow Scan
TV which amateurs use? "Jim Shaffer, Jr." wrote in message ... On Friday's edition of Allan Weiner Worldwide, Michael Ketter announced that WBCQ's 5.105 MHz station would transmit its ID in SSTV at the top of the hour during "Area 51", Sunday nights from 6 to midnight Eastern US time. |
#4
![]() |
|||
|
|||
![]() "Maximus" wrote in message link.net... OK, so what the heck is SSTV s ? Yes, my question as well. |
#5
![]() |
|||
|
|||
![]() Mike Terry wrote: "Maximus" wrote in message link.net... OK, so what the heck is SSTV s ? Yes, my question as well. Slow Scan TeleVision... Hams use it, some pirates are now using it... |
#6
![]() |
|||
|
|||
![]()
On Sun, 04 Apr 2004 13:29:25 -0400, "Jim Shaffer, Jr."
wrote: On Friday's edition of Allan Weiner Worldwide, Michael Ketter announced that WBCQ's 5.105 MHz station would transmit its ID in SSTV at the top of the hour during "Area 51", Sunday nights from 6 to midnight Eastern US time. Go to http://www.barberdsp.com/ for the Cpix program or http://www.qsl.net/mmhamsoft/mmsstv/ for the MMSSTV program Then tune to 14.230 or 14.233 MHz USB to try it out. Jim |
#7
![]() |
|||
|
|||
![]()
On Sun, 04 Apr 2004 18:13:33 GMT, "Maximus" wrote:
OK, so what the heck is SSTV s ? Slow-scan TV. It's basically a color version of a fax transmission. There's a good free decoder program at http://www.qsl.net/mmhamsoft/mmsstv/ I didn't hear any SSTV signals on WBCQ tonight. They had mentioned installing a new computer at the station, so maybe they didn't get it ready in time. If you want to test the program, 14.230 MHz USB is a popular frequency on weekends. |
#8
![]() |
|||
|
|||
![]()
"Jim Shaffer, Jr." ) writes:
On Sun, 04 Apr 2004 18:13:33 GMT, "Maximus" wrote: OK, so what the heck is SSTV s ? Slow-scan TV. It's basically a color version of a fax transmission. There's a good free decoder program at http://www.qsl.net/mmhamsoft/mmsstv/ I wouldn't call it that. The scheme is 45 years old. It's tv with the vertical and horizontal frequencies slowed down, so the resulting video signal can fit into the bandwidth used by a voice signal, The tradeoff is that the scan rate is so slow that it takes seconds to transmit a picture, something like 8 seconds originally. When it came into being circa 1958 by Copthorne Macdonald (I can't remember if he was the outright inventor or if he made it practical based on theory from elsewhere. He wrote some articles in 1958 or 1959 for QST, and that would be the original source. He wrote a column for Mother Earth News in the seventies, and was the SSTV columnist for CQ magazine in the early seventies), there weren't computers to do the work, so the only way to display them was with long persistence cathode ray tubes, the specific type surplus out of radar screens I think. Without that long persistence, by the time the full picture had been "painted" on the CRT the earlier portion would have faded. It's absolutely no good for motion, because it take so long to scan the original image. I do know when surplus fax machines came along in the seventies, this is old style fax machines, they were compatible or closely compatible with SSTV, and I don't know if that was a deliberate part of the SSTV specs. IN the seventies, as digital logic and memory became common and cheaper, there was a drive away from special displays. So scan converters came into being which would assemble the picture from the SSTV signal, and then read it out at the fast rate that a common tv set expected. And people moved to common TV cameras, again with the use of converters, so it was a whole lot easier to set up, and regular video equipment is a lot more common than SSTV equipment. Of course, when computers came along, they could be used to do that work, and I suspect virtually nobody uses dedicated equipment at this point. I think there were color experiments in the seventies, but they really made a splash once computers were common. It made it a whole lot easier. But color is not what makes SSTV. The standards may have change, I haven't kept track in recent years. Michael |
#9
![]() |
|||
|
|||
![]()
I believe that the video over a phone line, for example, is slow scan. Used
with narrow band receiving devices, it's seen as video that jumps from one still picture (frame) to another. As does FAX, it operates at voice range audio frequnecies. Bill, K5BY |
#10
![]() |
|||
|
|||
![]()
Wasn't SSTV out and in CQ in the 60's or 70's in monocolor from some company
named Robot 2nd: Why buy this stuff to see some blurry mug, stupid bowling pin's or especially a call sign once an hour.......make no sense. Am I missing something here ? - "R.F. Collins" wrote in message ... On Sun, 04 Apr 2004 13:29:25 -0400, "Jim Shaffer, Jr." wrote: On Friday's edition of Allan Weiner Worldwide, Michael Ketter announced that WBCQ's 5.105 MHz station would transmit its ID in SSTV at the top of the hour during "Area 51", Sunday nights from 6 to midnight Eastern US time. Go to http://www.barberdsp.com/ for the Cpix program or http://www.qsl.net/mmhamsoft/mmsstv/ for the MMSSTV program Then tune to 14.230 or 14.233 MHz USB to try it out. Jim |
Reply |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
FS: ROBOT SSTV EQUIPMENT | Boatanchors | |||
FS: ROBOT SSTV EQUIPMENT | Boatanchors | |||
WBCQ vs Hal Turner | Shortwave | |||
SSTV: decoding Kenwood KVT-10 "Color 1" format | Digital | |||
SSTV: decoding Kenwood KVT-10 "Color 1" format | Digital |