----- Original Message ----- From: "Mark Vandewettering" kf6kyi@gmail.com To: "AMSAT-BB" amsat-bb@amsat.org Sent: Wednesday, June 18, 2008 9:49 PM Subject: [amsat-bb] Re: LEO's
On Jun 18, 2008, at 2:46 AM, i8cvs wrote:
Hi Art, KC6UQH
You are correct 100% because the HEO AO40 was very easy to work using any old TX capable to run about 50 to 100 watt into 70 cm CW and SSB
A 3 to 4 foot dish with a 2400/144 MHz downconverter in the focal point and connected to any old 144 MHz CW/SSB receiver mounted on the balcony was sufficient to receive a nice downlink from all over the world by many users at the same time for many hours every day.
No complicated TX/RX radios and special software was necessary to compensate for doppler just made by hand.
Well, sure, if you want to reduce ham radio to just keying the mic, leisurely yapping along for hours at a time, then by all means, let's have more satellites in HEO. But where's the skill in that?
Hi Mark, KF6KYI
The skill is in building about everyting by yourself like low noise preamplifiers for 2 meters, 70 cm, 13 cm and high dinamic range downconverters for the above bands plus an Automatic Noise Figure Meters to get the best Noise Figure, build transverters from 2 meters up to the MW, build different type of feed for dishes having hours to test their efficiency through the HEO satellite in cooperation to many and many experimenters worldwide and discuss the problems with them improving your knoledge in radio-technique.
Probably to build about everyting by your self for a satellite for all like an HEO make you a real experimenter because if you are not succesfull you cannot send the equipment to the manufacturer but you are obliged to study your problem by your self looking and reasoning over your own schematic diagrams.
When OSCAR-10, OSCAR-13 and AO40 where alive and well we all were assisted in solving our technical problems by some well know teachers and radio scientists every day on this BB like James Miller G3RUH, Charles Suckling, G3WDG and Tom Clark W3IWI now K3IO but unfortunately they actually desappeared from this BB because they are not anymore interested to discuss about the technical level and matters actually seen on this BB.
Read please into the AMSAT-BB archive and compare the importance of both technical and operating contents of messages at time in wich OSCAR-10 OSCAR-13 and AO40 were operational and I am sure that you will learn more and more about the purposes of the Satellite Amateur Radio for the benefit of your own skill.
Hell, you don't even need to know what Doppler is with these easy HEO satellites. If you want to take the easy way out though...
Every experimenter know what the Doppler is but if you like to make your life difficult with Doppler for a few minutes QSO having the time to only say.......Five.......Nine.......class.......class ! and then come into this BB asking for the call letter of the guy you suppose have made a QSO then it is better to stay with the FM satellites !
Mark KF6KYI
Best 73" de
i8CVS Domenico