Posted: 6/1/2004 7:16:11 PM EDT
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Hello Gents, I am reading up on HAM radios and I plan on getting my license this summer and I'm not too savvy when it comes to radios so I have an easy Q for you to A. Looking at Watts and I was wondering if the Tx wattage effects the Rx range? Or is it just what ever hits my antenna is what my radio will hear. Or does a HAM radio actually suck waves out of the sky and the higher the wattage the further away I will be able to pick up? I guess this question goes for scanners too, does apply? Thanks for your help!! |
You are just starting!  The output wattage is how much power you're sending up the antenna - just like with any power emmission the law of squares applies - if you want to double the output of a 4 watt transmitter you'll need 16 watts. Doubling the power moves the "s" meter one more unit (which ain't squat). The receiver sensitivity is what measures how sensitive the radio is to incoming signals. Here a lower number is actually better. 9 to 11 mVolts is typical. With both cases a few dollars spent on a better antenna means everything. You'll transmit and receive better off that same antenna. Getting an antenna with 4-6 dB is like getting a large amplifier. I have a 13 element 440 Mhz beam (about three feet long) that gives me the gain of (nearly) a 400 W amplifier from my little 5 watt transmitter. A 400 watt 440 Mhz transmitter might cost $500. The antenna was like $40.  I run 70 cm/440 MHz, 1.25 m/223 MHz, and 2 m radios with most of my work done in the 440 and 223 range. The 2 meter band around here is full of illegals - both aliens and operators and is nearly worthless. My club owns and operates K6AFN on 1.25 meters with is 223 MHz The 440 MHz just isn't as common, is great for point-to-point communications, and uses much smaller antennas which makes it nice to mount a "huge" gain antenna on the house, car, and HT. |
| Scanner antennas are a bit more difficult as they're designed to cover very large portions of the spectrum so they're not optimized for anyone frequency - meaning very little if any gain (signal reception boost). If you're trying to listen in on one band or even a single frequency then you can use a ham radio transmit antenna to receive on. The transmit antenna is cut/shaped/sized to give boost to a one or more small areas of the spectrum which allow it to be more sensitive to those frequencies and less sensitive to others (like the AM/FM/TV/cell phone bands). |
Actually doubling the power represents a 3dB increase. An "S Unit" is normally a 6dB increment, however many modern transceivers have their own interpretation of what an "S Unit" is. Some radios don't even have "S Unit" scales at all. Theoretically, if a 10 watt transmitter produced an S-5 on a receiver's meter, increasing that power to 40 watts would produce about an S-6. 160 watts would show an S-7, and so on. _. _ _ _.. .. ._.. _ _. |
You're shittin' me?!?! Sounds like CB now or what? Are they infiltrating 10 meters a lot now too? I've been out of the hobby for a few years now, thank God, but I still have a couple HTs for camping and scanning. The bands around here are so dead it isn't even funny. |
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Yah gotta remember that SoCal has about 15 million folks, of which the normal subset percentage are Hams, with the normal sub-subset percentage of assholes. Add up that all the repeater pairs are probably triple booked and depending where you are you might hit up to 3 repeaters on the same freq. And if really lucky you get highpower coming in from Mexico and a certain percentage of non-licensed outlaws. IIRC some of the repeaters are pretty much reserved by the potty mouths. Don't you love it when grown men try to impress you by talking like a Marine boot? I think I briefly found a place where I could hit/hear 4 146.97 machines at once. It was over by Griffith Park/Glendale. I got the one at Hughes in Fullerton (maybe the remote receive in La Habra Heights), the one up by Crestline, one down by Oceanside someplace and one out by Valencia/Canyon Country. But antennas don't suck signals. If the signal hits it and is strong enough to be processed by the radio, you will hear it. You can get garbage when the strength is high enough to break squelch but not strong enought to be "read". |
| Oh yeah, I realize the CAncer state has a lot of hams, a lot of which ARE assholes. Just listen to 20 meters or 75 phone at night, LOL. I've heard they were pretty foul-mouthed before, but don't have experience to comment. Here in the valley it's always been the opposite! I used to belong to a simplex group, and the ARA (Arizona Repeater Assoc.) hated us not giving them money and using their repeaters. We were a wild buch and weren't afraid to say a bad word or two. Jokes were often tasteless and the comments crass, but nothing shocking. We simply had fun like normal people. The ARA used to jam the frequency and everything. Really immature. It got to the point that both sides were giving each other shit, and it was a pain in the ass just trying to enjoy the hobby. Me and a few other guys with good antennas went to 440. I got so tired of putting up with the shit, I finally sold everything. I don't plan on looking back. |
| Hate to hear the bad Ham news in some parts of the country. Here in WV Hams are still respectfull of the bandwidth, in fact I own a repeater on 444.575 tone of 151.4 here at my QTH which is about 1300 feet above sea level and gives me a good footprint of 25 miles. The system is on Echolink fulltime and can reach out to other amateurs world wide with my handheld Kenwood with others on Echolink (VOIP). Still enjoy all modes of HF. |