Activity Stream

Filter
Sort By Time Show
Recent Recent Popular Popular Anytime Anytime Last 24 Hours Last 24 Hours Last 7 Days Last 7 Days Last 30 Days Last 30 Days All All Photos Photos Forum Forums
  • G7NFP's Avatar
    Today, 15:13
    G7NFP replied to a thread Pre-Noob in Introduce yourself
    BTW Dan. Don't know about USA, but in UK the difference between CB radio (11m) & 10m ham radio is..... CB radio (11m)........... 4w max FM only Ham radio (10m)........ 26dbw max (which is about 400w). all modes. Hell of a difference don't you think? Remember to pop back & tell us you aced the exams.
    19 replies | 292 view(s)
  • R2D2's Avatar
    Today, 14:22
    R2D2 replied to a thread Pre-Noob in Introduce yourself
    If two people are drowning, which one do I save? The answer from a swimmers point of view is the person most alive. From a lifeguards point of view is the one I come across first.. The test proves absolutely nothing, doesn't mean a thing, it just shows that you put forth an effort to attempt to learn something so that you don't hurt yourself or someone else. The only difference between amateur radio and the citizens band is 1 megahertz. As for us being old farts, that only shows how disrespectful you are. Good luck getting anyone knowledgeable to help you. With your attitude you will quickly run out of new people to talk to.. Once they discover your attitude, they won't talk to you. You will end up running digital modes on your computer where no one talks to each other. I tried to explain things to you, but your mind is already made up.. Hopefully you will stay on a walkie talkie where only a small portion of people will be exposed to your attitude..
    19 replies | 292 view(s)
  • G7NFP's Avatar
    Today, 11:16
    G7NFP replied to a thread Pre-Noob in Introduce yourself
    No electrical appliance safety checks for American companies? I think you will find that there are more regulations in place than you are aware of. Every business in Europe must have all appliances tested yearly. People cannot protest against safety checks. But it only applies to registered companies. Not private households. But any electrical work in any household must be certified by a qualified electrician. Having said that. I have completely rewired many houses. So it's very difficult for the authorities to regulate. But before l sold my houses l had the electrical work checked & signed off by a person qualified to do that. I am also a very good plumber. Just over a year ago l installed a complete bathroom for my mother as the plumber wanted over 2k labour charge. Sadly she had a heart attack 2wks after l completed it. So that house became mine the day she died as she put it in trust to me. Guns? Very strict control in UK. They banned all private ownership of handguns in 1995 when a psycho walked...
    19 replies | 292 view(s)
  • 5B4AJB's Avatar
    Today, 11:13
    5B4AJB replied to a thread Wooshing noise HF in The Junk Box
    Most likely ADSL or switch-mode power supplies - welcome to the 21st century :/
    1 replies | 44 view(s)
  • dnwiebe's Avatar
    Yesterday, 22:55
    dnwiebe replied to a thread Pre-Noob in Introduce yourself
    Huh. I've never owned a business, but I've never heard of anything like this in the US. My suspicion is that it doesn't happen, at least not on that scale. There are exceptions; for example, if your business is selling firearms, you have to be prepared at any moment to have government agents come onto your property, shut you down temporarily, and verify that the guns you have in inventory match the list they have--especially if you sell full-automatic weapons. The federal database is notoriously full of garbage, so when the feds decide to audit you you may be "temporarily" shut down for quite awhile while they essentially use your inventory to clean up their database (or just use the discrepancies as an excuse to cart you off to prison, if you piss them off). Or if you run a flight school, there are federal regulations about how often you have to have your airplanes professionally inspected and what you have to check for and how often; but even then, practically, it's less a government thing than an...
    19 replies | 292 view(s)
  • dnwiebe's Avatar
    Yesterday, 21:15
    Iím assuming that my handheld canít be detected by his repeater and his handheld canít be detected by my repeater. (Strictly a thought experiment at the moment, but it seems a reasonable one.) And Iím saying ďmyĒ repeater and ďhisĒ repeater in terms of proximity, not actual ownership, of course. So if I donít own the repeater, I have no control over which other repeaters itís networked with via UHF or Internet. But thanks for your help. Now at least I have another possibility to track down. Shalom, Dan
    12 replies | 260 view(s)
  • Fcchief's Avatar
    Yesterday, 19:15
    Fcchief started a thread Wooshing noise HF in The Junk Box
    Hi, recently got back into ham radio after long hiatus. I bought a Icom 746PRO, and put up both end fed antenna (approx 51' long, sloping from about 30 feet to 18 feet) with a 9:1 homemade xfmr, also bought a 40 Meter Standard TAK-Tenna and have that raised about 5' above ground on pvc pipe with the radials laid out. I hope to get a GAP Challenger which I had in the mid 2000's which at the the time did great even though I was living in what my dad called an RF hole. Ok question on HF on both my antenna's I get a whooshing sound that just about drowns everything else out. 20 meters seems the worst. I can pick up some activity on 40 but not much. My place is about 400 yds from Puget Sound and I can see downtown Seattle from my front deck. There are power lines approximately 175' from where the antenna's are. The end fed is running from a large cedar down to my roof since that is the only way I can run a wire antenna due to lack of space. I am at a loss as to what that noise is, as I have never experienced...
    1 replies | 44 view(s)
  • jhodgski's Avatar
    Yesterday, 18:52
    Hiya Martin, Thanks for the reply, but the manual only mentions jumpers K-1 to K-7. The only mention of K8 is in the parts list. Cheers, James
    2 replies | 171 view(s)
  • K6CPO's Avatar
    Yesterday, 17:45
    Most repeaters, linked or not, are open to all licensed amateurs. It's just a matter of courtesy that you wait your turn for a repeater, unless, of course, it's a life and death emergency. I'm unaware what the link frequencies are for that system. I'm not sure what you're trying to accomplish with your example. You mention "co-worker" so I assume you are both in the same general locale. One repeater with the proper placement would allow the two of you to converse with each other. And it really doesn't matter if it's yours, his or someone else's. Even if the repeaters are in separate cities (per your example) linking as I described in my previous post is how to accomplish that.
    12 replies | 260 view(s)
  • dnwiebe's Avatar
    Yesterday, 16:43
    Okay, so what Iím getting is that there are multiple reflections, not just one, and they form a series that is technically infinite but in real terms converges quickly. Since reflections are perfect and transmission is lossy, youíd want a high damping factor so that the series converges as quickly as possible, resulting in fewer high-energy trips down the lossy cable. (I assume nobody cares about the tail-end low-energy reflections that lose only microwatts per trip.) Okay, that all makes sense. I appreciate that. It leads to another question, though. Do these reflections smear the impulse response of the transmitter out over time? It seems like theyíd have to. One very short blip of transmitter power would produce a series of diminishing echoes in the radiated signal. Yes? The length of the smear would depend on the number of reflections and the length of the cable. Does this cause a problem with a fancy name I havenít learned yet, or is it always lost in the phase distortions caused by all the...
    4 replies | 154 view(s)
  • k7mem's Avatar
    Yesterday, 13:57
    It is a little more complicated than just being lost as heat. But you are correct, in that, the tuner doesn't fix a mismatch. It only allows the transmitter to see a good match. The high SWR causes much of the power reflected back to the antenna tuner. But at the tuner, there is also a mismatch and some of that reflected power is reflected back to the antenna. This happens over and over, until there isn't anything left. And, of course, some of the power is simply lost as heat in the coax. On my web page on UHF/VHF Antennas there is a small calculator for calculating the Loss Due To SWR. The equations for this calculation are also listed. So, in your scenario of 100 watts (at 146 MHZ), assume that you are feeding the antenna with 100 feet LMR-400 coax. The amount of power that will be radiated would be 35.272 Watts. The rest of that power is lost to heat, due to the resistance in the coax. If you instead had 50 feet of same coax, you would be radiating 52.926 Watts. So about half of your power would...
    4 replies | 154 view(s)
  • R2D2's Avatar
    Yesterday, 13:40
    http://www.wc7i.com/reflection%20section.htm?fbclid=IwAR2NSQQCOLnJXNkXwwBQL6wluhEDJZSSMLTs11CLSJSVY7sTYWXeYP2vTk8
    4 replies | 154 view(s)
  • Tempstar's Avatar
    Yesterday, 12:44
    You're on the right track. The tuner presents 50-52 ohms to the final output stage of the radio to make it happy and prevent reflected power from heating the finals to the point of destruction. Since energy in = energy out, the wattage that cannot be absorbed by the antenna and feed line system is lost as heat.
    4 replies | 154 view(s)
  • G7NFP's Avatar
    Yesterday, 12:17
    G7NFP replied to a thread Pre-Noob in Introduce yourself
    https://learntechnique.com/what-is-pat-testing/?ppc_keyword=&gclid=CjwKCAjw2a32BRBXEiwAUcugiJMFTewwaUxuBOU4qDsYetdqm3MJdbUkjrQBy3B7WrwJniZh_8NAXRoCCMcQAvD_BwE No doubt there is an American equivalent. All electrical appliances in "every" business must be tested every year. Companies usually have a tester come in once a year, test everything. IE: every PC, in fact anything that plugs in, right down to the tea break kettle. But they usually have a couple of their employees qualified to do that testing for the odd items purchased in between the annual testing. So having that certificate is a ++ to any employer. When l was in electronics, one of my mates mentioned to someone what my previous career was. (Registered nurse). That news went round like wildfire. So when guys sustained injuries they would come to me as they wanted their injury assessed by a registered nurse rather than a first aider. That pissed off the company. Therefore their solution was to send me on a course for a week to qualify as an...
    19 replies | 292 view(s)
  • dnwiebe's Avatar
    Yesterday, 01:47
    dnwiebe replied to a thread Pre-Noob in Introduce yourself
    Yeah, but I'll bet it's not all crap. I'm probably too ignorant at the moment to reliably distinguish crap from not-crap, but hopefully I won't always be, so I'll save it up and go through it then. And anyway, at least on this board I have no reputation to defend. But in my life I've known enough crotchety old geezers (and as a matter of fact am well on my way to becoming one myself) to understand that the crotchety isn't usually personal. Here's a story about me. I'm an old software developer with very particular ideas about how software should and shouldn't be written. You know those nickel-plated spades that politicians use to break ground in front of the cameras on new construction projects? The ones that are engraved with something and hung on the wall in glass cases? I found a place once that made those. Well, they didn't make them, but they bought normal spades and nickel-plated them and engraved them to order. So at one of my jobs I bought five of those, and had them engraved with what I...
    19 replies | 292 view(s)
  • dnwiebe's Avatar
    Yesterday, 00:42
    Suppose you have a 100W transmitter. You hook up a homemade antenna to it and try transmitting. The transmitterís onboard SWR meter shows 10:1 SWR and the power amp is automatically rolled back to a watt or two to protect the output stage. You say, ďNo problem; Iíll just grab my handy-dandy antenna tuner here.Ē So you insert the tuner, plus an outboard SWR meter, and tune until the radioís SWR says 1:1. Now your transmitter is pumping the whole 100W and everything looks happy...but the outboard SWR is still showing 10:1. That means 1/11 of your power is being radiated and the other 10/11 is being reflected, right? The tuner doesnít actually make the bad antenna better, it just makes it look better to the transmitter. Or so Iíve read; I have no experience of my own.
    4 replies | 154 view(s)
  • tngw1500se's Avatar
    Sun 24th May 2020, 21:34
    tngw1500se replied to a thread What to buy? in Amateur Radios
    removed today
    14 replies | 330 view(s)
  • dnwiebe's Avatar
    Sun 24th May 2020, 20:47
    Okay, that's something I didn't know. Separate repeaters that all broadcast the same signal at once. On the one hand, that would make it really handy if you were the guy using the repeater; on the other hand, it would make it really annoying if somebody else was using the repeater and you had traffic waiting for it. Curiosity: the UHF links between the repeaters: are they on amateur frequencies or commercial frequencies? Of course, if my repeater and my coworker's repeater aren't in the same network, we'd still have to bodge together something like my example, yes? Thanks, Dan
    12 replies | 260 view(s)
  • dnwiebe's Avatar
    Sun 24th May 2020, 20:18
    dnwiebe replied to a thread Pre-Noob in Introduce yourself
    It's never occurred to me that a ham license might be professionally beneficial to me. Interesting. I can't see how it could be at the moment, but perhaps there are additional careers in the offing for me the way there were for you. If so, who can say? I used to be a CBer...I think I probably still have a transceiver and antenna in my truck somewhere. It's not mounted or connected, but some years ago I convinced myself that it was a good idea to have one in there for emergencies. Nowadays I have a cell phone, but I've never gotten around to taking the CB out of my emergency kit. Well, so far I have a nine-inch rubber-duck antenna and something between thirty milliwatts and five watts of transmit power. I haven't even been able to hear the bowel-discussers yet. (I heard what I'm pretty sure was some digital traffic on a local repeater--sounded a lot like a telephone modem--but that's the only amateur traffic I've heard yet.)
    19 replies | 292 view(s)
  • G7NFP's Avatar
    Sun 24th May 2020, 20:17
    G7NFP replied to a thread Pre-Noob in Introduce yourself
    And...ROFLMAO I just noticed that you stood up to the old f**t. He tends to spin a load of crap to all the new guys who post in this section. Must admit l got a little annoyed when he decided to criticise me. See the thread in this section "So green l'm still a seed". He gives a lot of advice on that thread that l am sure will be of great help to you.... ;-)
    19 replies | 292 view(s)
  • K6CPO's Avatar
    Sun 24th May 2020, 20:15
    What you're proposing has already been done. I think your example makes it more complicated than it really is. In Southern California, there is a system of repeaters linked via a UHF radio link that connects four repeaters, two in California and two in Arizona. It's called the CALZONA link and is a joint collaboration between the East County repeater Association in San Diego and the Arizona Repeater Association. Anything that goes into one repeater comes out on the other three simultaneously without regard to offsets or frequencies. Four separate operators could hold a conversation, one on each repeater with no difficulty. There is also the WinSystem, a bunch of linked repeaters spanning the better part of the West Coast, California to Washington state. Most of these are linked via the internet, but the concept is the same as using a radio link.
    12 replies | 260 view(s)
  • K6CPO's Avatar
    Sun 24th May 2020, 19:42
    K6CPO replied to a thread What to buy? in Amateur Radios
    Maybe so, but there is nothing you can do about it. It's codified in Federal Regulations. It's simple... If you want an amateur radio license, you have to take the test. Period. Your reasoning is why there are radio services that don't require examinations (GMRS) or even physical licenses (FRS, MURS or CB.) The latter three are "licensed by rule" meaning that as long as you follow the regulations governing those service, you can use them without a license. The trade off is that there are more restrictions on things like radio types, power limits and channels available. You've been offered some choices about what's available to you. You just have to choose which way you're going to go. Further whining about it isn't going to change anything.
    14 replies | 330 view(s)
  • tngw1500se's Avatar
    Sun 24th May 2020, 16:29
    tngw1500se replied to a thread What to buy? in Amateur Radios
    Not everyone who drives a car changes the cam and I'll bet that most ham operators never replace a transistor or a green wire or a fuse for that matter. Radios today require a microscope to work on. How many ham operators even own a soldering gun? Nikola Tesla couldn't repair one. The purpose of a radio is communication. These questions are unnecessarily discriminating against persons who lack technical knowledge. Sure there's a few hams that tinker with radios and antennas but I'd say most install a radio, antenna and just use it after that. Hams call it a "hobby". Some people would just use a radio to talk to others on. Knowing what a green wire is doesn't make for a better radio "operator". I can rewire my whole house. My wife can't but she turns on the bathroom fan all by herself. It's amazing.
    14 replies | 330 view(s)
More Activity