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#311
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![]() wrote in message ups.com... You've probably heard the old engineering adage: "You can have it fast, good or cheap. Choose any two" All Shannon's Theorem does is equate fast to data rate, good to S/N, and cheap to bandwidth. BINGO! That's exactly the problem. What is Jim going to give up to get it? Dee D. Flint, N8UZE |
#313
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Dee Flint wrote:
wrote in message ups.com... You've probably heard the old engineering adage: "You can have it fast, good or cheap. Choose any two" All Shannon's Theorem does is equate fast to data rate, good to S/N, and cheap to bandwidth. BINGO! That's exactly the problem. What is Jim going to give up to get it? And my, have we come a long way from simply hooking up a modem To our rig haven't we? Lessee, Split operation, perhaps 2 modems? Lotsa power, very high quality transmitter and PA, as well as a great soundcard. A marked sensitivity to phase distortion. At HF, it would be a very expensive system that would work on a good day maybe. And it is a superior thing? Makes BPL look like a masterpiece! - Mike KB3EIA - |
#314
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From: on Wed 6 Jul 2005 15:54
wrote: From: on Tues 5 Jul 2005 16:41 John Smith wrote: N2EY: First, you can run duplex, simply use two modems and a separate transmitter and receiver. Uh-huh. Got it. The reciever listens while the transmitter transmits. On the same frequency. 'Way to go "John", slap a patent on it! Did John say "on the same frequency?" I don't think so. He didn't say *not* on the same frequency either Sweetums. Now what? Two questions: 1. What ELSE did John "*not* say?" 2. What are you going to say he "really said?" :-) This is all very clever of you, but it really boils down to YOU saying a lot of snit (that another didn't say) and then trying to tap-dance around admitting you fudged things up. Next time just accept being caught and hang up. Do NOT try to MAKE UP STORIES to try and snow-job everybody. It doesn't work and it annoys the other pigs. FULL duplex IS possible using SEPARATE frequencies for transmit and receive. No kidding Sweetums I've done it several times myself. With my own equipment operated under my own operators and station license. Mostly I think you "did it" with only your own computer and more literary license than you ever earned. :-) But, that's just my opinion...and with some considerable thinking about HF operations that hardly EVER go FULL duplex, senior. For one thing, the rather large near field at HF wavelengths mean you NEED considerable separation of antennas or the most bodaciously-many-section-dual-filter to keep the unwanted frequencies (transmitter leaking into receiver) OUT. That attenuation has to be VERY large in order to keep the receiver input from overloading. Now, WHY would you want to go FULL duplex "operating under any license?" for personal use? You would need someone at the other end of the circuit doing the same thing...and that is an almost- extreme rarity. Telephone Cell sites operate 24/7 at FULL duplex. They HAVE to and the equipment is designed to do that...such as separate transmitting and receiving bands with plenty of diplexing filter connecting the transmitter(s) and receiver(s). The General Electric microwave terminals I've described used a (approximately) 5-foot long dual waveguide bandpass filter to keep separate transmit and receive frequencies from interfering with one another. The pulse-position-modulation pulse trains were not synchronous with one another, thus aiding in isolation. The peak power output of the transmitter was only 12 Watts (at base of antenna tower) yet the receiver was about as sensitive as one could get (using radar receiver techniques) of the 1950s. If you are going to mumble about "your own moonbounce" (what is mistakenly called "EME" by hams), then you need not worry about mutual interference. A return signal won't return from the moon for about 2.5 seconds, long enough for you to manually swtich coax or waveguide between transmit and receive (as one of the early ham moonbouncers did and pictured in CQ long ago). Or, you could go into broadband BS about using morse and auto- switchover Tx/Rx by fancy diode T/R switching...so much so that you could "read the other station between dots and dashes" like your buddie Jimmie once said in here. :-) But in your case of course . . sigh In "my case" you are resentful/insulted/irritated because another had LONG AGO experience in something YOU DID NOT. shrug I've come to expect that in here from the self-propelled wunderkinder of the PCTA extra crowd. It's practically a given. :-) |
#315
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wrote:
From: on Wed 6 Jul 2005 15:54 wrote: From: on Tues 5 Jul 2005 16:41 John Smith wrote: N2EY: First, you can run duplex, simply use two modems and a separate transmitter and receiver. Uh-huh. Got it. The reciever listens while the transmitter transmits. On the same frequency. 'Way to go "John", slap a patent on it! Did John say "on the same frequency?" I don't think so. He didn't say *not* on the same frequency either Sweetums. Now what? Two questions: 1. What ELSE did John "*not* say?" John said it was easy. The way it is turning out is anything but. We were going to attach our 56K modem to our rig, IIRC. One quick connection, and welcome to the modern digital world for the olde tyme hammes. DAT's okay, those Olde tymers would probably just use it to send Morse code sounds anyhow. ;^) 2. What are you going to say he "really said?" :-) We thought we would let that part up to you. 8^) - Mike KB3EIA - |
#316
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Dave Heil wrote:
Mike Coslo wrote: No point to it. Not sure why he is so anxious for us to launch something. I don't recall setting any particular deadline. No biggie. Surely you know that Len is the very opposite of being anxious for you to launch. If you had a sucessful launch, it'd take away his ammunition. I doubt that, Dave. 8^) - Mike KB3EIA - |
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