Post by Site Admin on Dec 6, 2003 17:12:51 GMT -5
SSTV, or Slow Scan TV, is a way of interconnecting amateur rigs to computers equipped with sound cards, thereby allowing still pictures to be sent via amateur radio. Think of it as a fax over the airwaves, but without the cellphone company charges!
It's an amazing and relatively new way to use ham radio. The best part is, it's not expensive at all!
There are many SSTV programs available on the net, but the one I like best is freeware: it's called MMSSTV. It was developed by Makoto Mori, JE3HHT. You can find the english language version of the program here: www.qsl.net/mmhamsoft/
Many ham operators and SWL's also have computers with internet access. This makes it easy to obtain the software, and to have a platform already capable of using it.
The tricky part is how to interconnect the rig with the computer.
The easiest way is to purchase a device called a RigBlaster. Following the naming convention of the most popular early PC sound card, the SoundBlaster, this device forms the link between your rig and your PC. It comes with all necessary connections, as long as you order the version for your rig. Often times, the version for one rig may work on another, since the connections of the two rigs are sometimes very similar.
In most cases, you can use a microphone attatched to your PC when you need to send your call sign or other info during a SSTV transmission.
The other way to create the link between your PC and rig is to custom-make an interface. You will need to know the pinout of the mic connector on your rig. You will also need to have connectors to feed from the output of your sound card, and the "line in" of your sound card, as well as the external speaker connector on your rig. Depending how your rig and computer are configured, you may also need a "Y" connector, so that the output of your soundcard can feed both the mic line of your rig as well as a pair of computer speakers, so that you can monitor the transmission.
SWL's can monitor SSTV transmissions, and receive the still pictures also. You just won't be able to reply with a picture of your own until you get licensed!
A more difficult way to do this is to have a microphone on your computer that is placed near the speaker on your rig. Then to transmit a picture, you hold the rig's mic close to your PC speakers. It's crude, but it does work. Just beware of "room noises" when broadcasting that way. If someone stubs their toe across the room from you, and begins to cuss and swear, you may inadvertantly be broadcasting the cussing!
All classes of licenses can send SSTV on the 2m band, as well as many other bands. Be sure to check the latest bandplan information, and restrict your SSTV transmissions to the part of the band allocated for it.
One caution: it may be best to avoid SSTV over repeaters. The "digital noise" sent by the computer when transmitting the pictures may be captured by some repeaters as control codes. It's best to use simplex for all SSTV transmissions.
The locals around here hold a SSTV simplex net on the 2m band every Monday night. Check your local area for similar info. If there's no such net around you, why not start one?? ;D
73's!
It's an amazing and relatively new way to use ham radio. The best part is, it's not expensive at all!
There are many SSTV programs available on the net, but the one I like best is freeware: it's called MMSSTV. It was developed by Makoto Mori, JE3HHT. You can find the english language version of the program here: www.qsl.net/mmhamsoft/
Many ham operators and SWL's also have computers with internet access. This makes it easy to obtain the software, and to have a platform already capable of using it.
The tricky part is how to interconnect the rig with the computer.
The easiest way is to purchase a device called a RigBlaster. Following the naming convention of the most popular early PC sound card, the SoundBlaster, this device forms the link between your rig and your PC. It comes with all necessary connections, as long as you order the version for your rig. Often times, the version for one rig may work on another, since the connections of the two rigs are sometimes very similar.
In most cases, you can use a microphone attatched to your PC when you need to send your call sign or other info during a SSTV transmission.
The other way to create the link between your PC and rig is to custom-make an interface. You will need to know the pinout of the mic connector on your rig. You will also need to have connectors to feed from the output of your sound card, and the "line in" of your sound card, as well as the external speaker connector on your rig. Depending how your rig and computer are configured, you may also need a "Y" connector, so that the output of your soundcard can feed both the mic line of your rig as well as a pair of computer speakers, so that you can monitor the transmission.
SWL's can monitor SSTV transmissions, and receive the still pictures also. You just won't be able to reply with a picture of your own until you get licensed!
A more difficult way to do this is to have a microphone on your computer that is placed near the speaker on your rig. Then to transmit a picture, you hold the rig's mic close to your PC speakers. It's crude, but it does work. Just beware of "room noises" when broadcasting that way. If someone stubs their toe across the room from you, and begins to cuss and swear, you may inadvertantly be broadcasting the cussing!
All classes of licenses can send SSTV on the 2m band, as well as many other bands. Be sure to check the latest bandplan information, and restrict your SSTV transmissions to the part of the band allocated for it.
One caution: it may be best to avoid SSTV over repeaters. The "digital noise" sent by the computer when transmitting the pictures may be captured by some repeaters as control codes. It's best to use simplex for all SSTV transmissions.
The locals around here hold a SSTV simplex net on the 2m band every Monday night. Check your local area for similar info. If there's no such net around you, why not start one?? ;D
73's!