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Uniden 525 VHF and general question
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Uniden 525 VHF and general question
In article ,
cavelamb wrote: What Wayne said... From what I've seen of "professional" work (unless you did it yourself and know), it would be worth checking. I think this whole discussion ,is just about as funny a thread ,as I have read, in months. If you don't have the right tools, and know what you are doing, you just "****ing into the Wind"... Yes, there are a few "Professionals" around who don't have Clue One, and there are some that can't afford to buy the "Correct Tools" to do the job. If you want a real Marine Radioman, you need to pay for his Knowledge, Service, and his Test Equipment.... or you can stumble around and learn it yourself, after much Trial and Error..... SaltyDog isn't even close to being a REAL Marine Radioman..... and his attempt to sidetrack the discussion, by introducing a Trivial, and for all Practical Purposes, irrelevant factor into the thread, is so silly as to show a lack of intelligence in the field. Oh well, folks can believe what they will, but it doesn't change the FACTS... and the issues at hand.... Wilbur, Well we all know about Wilbur... Enough said on that front.... -- Bruce in alaska add path after fast to reply |
Uniden 525 VHF and general question
On Mon, 14 Dec 2009 15:23:42 -0500, wrote:
Boy, somebody sure feels threatened. I don't think you should take it personally. "Bruce in Alaska" has more real world electronic experience, by far, than anyone else in this group that I know of. I've been FCC licensed in one capacity or another since 1957 and would defer to his judgement on just about anything. |
Uniden 525 VHF and general question
On Mon, 14 Dec 2009 15:39:49 -0500, Wayne.B
wrote: On Mon, 14 Dec 2009 15:23:42 -0500, wrote: Boy, somebody sure feels threatened. I don't think you should take it personally. "Bruce in Alaska" has more real world electronic experience, by far, than anyone else in this group that I know of. I've been FCC licensed in one capacity or another since 1957 and would defer to his judgement on just about anything. Bruce should give his opinion on the 214 versus the other cable recently discussed. And whether mil spec means anything. That's been questioned too, and I'm a bit confused. Which is ok. Lucky for me I don't have a radio. --Vic |
Uniden 525 VHF and general question
"Bruce in alaska" wrote in message
... In article s.com, "Wilbur Hubbard" wrote: "Wayne.B" wrote in message ... Agreed but you could have a bad connection which is heating up under load. BINGO! They use one of those crap, 'slow burn' fuses. They heat up and the extra impedance reduces the voltage. Get rid of it and put a higher amperage rated, fast burn fuse in - end of problem. Wilbur Hubbard Bull****.... Wilbur, you need to stick to stuff you know about.... as Peter Bennett pointed out, if the volume at the receiver dropped, but the background noise didn't change, then the problem is in the Modulating Deviation, not the Power Output.... This is FM not AM or SSB.... In FM, once you exceed 12 db of Receiver Quieting the Background Noise, changes are hardly perceptible, and in FM, the volume produced in the receiver is directly proportional to the Modulation Deviation of the Transmitter, until it exceeds the bandwidth of the Receiver. -- Bruce in alaska add path after fast to reply You don't read too well, dude. Skippy said the volume of his 'transmission' as heard by other listeners in nearby boats decreased noticeably after about a minute. So the problem is with Skippy's transmitter and not his receiver. If the fuse heats up and the voltage drops and the "low voltage" indicator flashes in the readout as Skippy indicated then that should tell you something. Duh! Wilbur Hubbard |
Uniden 525 VHF and general question
On Mon, 14 Dec 2009 21:24:55 +0000, goofball_star_dot_etal
wrote: On 14/12/2009 19:06, wrote: On Mon, 14 Dec 2009 18:51:00 +0000, goofball_star_dot_etal wrote: On 14/12/2009 18:33, wrote: On Mon, 14 Dec 2009 18:30:49 +0000, goofball_star_dot_etal wrote: On 14/12/2009 18:24, wrote: On Mon, 14 Dec 2009 17:50:24 +0000, goofball_star_dot_etal wrote: On 14/12/2009 17:48, wrote: On Mon, 14 Dec 2009 17:33:33 +0000, goofball_star_dot_etal wrote: On 14/12/2009 15:28, wrote: On Mon, 14 Dec 2009 15:15:48 +0000, goofball_star_dot_etal wrote: On 14/12/2009 11:00, wrote: On Sun, 13 Dec 2009 23:48:25 -0500, Wayne.B wrote: On Sun, 13 Dec 2009 15:14:31 -0500, "Flying Pig" wrote: I'll try to find someone with a SWR meter here tomorrow morning before we head out to our anchorage prior to going into the dock where we'll be leaving Flying Pig, and give it a whirl. One of the quirks of waterlogged coax is that it can exhibit a perfect 1:1 SWR ratio while transmitting little or no power because the signal loss is so high that nothing gets reflected back to the SWR meter. I also have the little cable and the mast-top antenna which proved the cable at fault in the original explorations; it will be easy for me to get a boat buddy to listen while I read some story or something on a remote channel and see if that cured it. That shortie, BTW, is LMR400, so should be fine for the test. I don't expect it's got much in the way of SWR issues :{)) OK As to sagging power, with an 880AH bank, I doubt that's a problem, Agreed but you could have a bad connection which is heating up under load. Accurate SWR measurements also require clear dry conditions. An overcast day will affect the readings. Probably a Ham's old wives' tale. Your average VSWR meter is not very accurate, although still quite useful. This leads to all sorts of BS. The device I use cost more than my boat.. Nope, not an old wives tale at all. Work out the _magnitude_ of the change in electrical length of the antenna due to water vapour for yourself. http://www.kayelaby.npl.co.uk/genera...2_5/2_5_7.html Oh, so you now acknowledge that it DOES make a difference... Okay! Yes, but it is "**** all". Here is what I said: Accurate SWR measurements also require clear dry conditions. An overcast day will affect the readings. After much huffing, puffing and posturing, you now admit that statement was absolutely correct. Apology accepted. Still not worked out how much the centre frequency shifts compared to the typical 2Mhz bandwidth? Hey, you were wrong. Man up and move on. Ask someone to work it out for you.. Wussy! It's about the same magnitude as shaving 2 thou off a 3ft. dipole, at most, unless I made a mistake doing it in my head.. Besides, shouldn't you tune for typical conditions not for Antarctica. This link I came across might be of interest to some. http://www.mike-willis.com/Tutorial/refraction.htm WIMP! |
Uniden 525 VHF and general question
On 13/12/2009 20:14, Flying Pig wrote:
it will be easy for me to get a boat buddy to listen while I read some story or something on a remote channel Are you sure someone didn't just doze off last time you tried? |
Uniden 525 VHF and general question
In article ,
Vic Smith wrote: On Mon, 14 Dec 2009 15:39:49 -0500, Wayne.B wrote: On Mon, 14 Dec 2009 15:23:42 -0500, wrote: Boy, somebody sure feels threatened. I don't think you should take it personally. "Bruce in Alaska" has more real world electronic experience, by far, than anyone else in this group that I know of. I've been FCC licensed in one capacity or another since 1957 and would defer to his judgement on just about anything. Bruce should give his opinion on the 214 versus the other cable recently discussed. And whether mil spec means anything. That's been questioned too, and I'm a bit confused. Which is ok. Lucky for me I don't have a radio. --Vic Well, it would seem from all the previous posts that there is some controversy about the recommended RF Coax for VHF Marine Installations on various Vessel type.... Hmmmm... Well the answers are fairly straight forward. It really depends on the installation. Small coax, RG58 types, are alright for runs less than 10 Ft. For runs up 100Ft, RG8 Types Should be used. RG213 is better than RG8 or RG8 Foam Core Types, due to Wx survivability, and Water Intrusion. The Price Difference between RG213 and RG214, is usually NOT a cost effective for a NORMAL Marine Installation, especially on a non-Commercial Vessels, where budgets are tight. For Military Installations RG214 is the MINIMUM. On commercial vessels up thru the 80's, RG213 was the standard, for runs under 100 Ft. Then the newer coax types became available, like Belden 9913 & 9914. These were touted as the Poor Man's Heliax, and looking at the Specs back then, they were. They are iffy for Marine Use, mostly because of Bending Radius Specs, AND 9913 is a Hollow Core Type, so any water intrusion issues ruins the cable. The LMR Stuff around NOW is similar to the Beldon stuff, and has the same issues in that some is Hollow Core and it has limitations in Bending Radiuses. For Runs longer than 100 Ft. Heliax was the only thing used, in the Old Days. Modern replacements have come along in the 80's and 90's that are better on Price with similar Specs. In all this the Installation is the CRITICAL Factor, NOT the coax type used. Water Tight Fittings and Connectors, and getting the connectors INSTALLED CORRECTLY, is far more important than 213 vs 214 issues. I kind of doubt that many of the folks that read this Group even know how to install a PL-259 correctly. If you can do it in less than three minutes, you don't have a clue. 99% of Vhf Antenna System failures are do to installation issues, or CHEAP Antennas. If your paying someone to look at you stuff, and he brings anything aboard to check the VHF Antennas other than a Bird Wattmeter with the appropriate Slugs, kick them off your boat as if they had Homeric Fever, because they are Dufus's and will only cost you money. If you take your radio to a Service Shop and the guy Doesn't have a Real Service Monitor, Do NOT have them work on you rig. They are hacks and don't deserve your business. Even IF these folks show up with ALL the Right Tools, that doesn't mean they know what is what, it only means the have the Tools. Watch them like a hawk. Ask Questions. Experience Shows, and any Good Radioman will be more than happy to explain what he is doing and why, AND will show you exactly what your problem IS and what it will take to correct it. I was always willing to show my customers everything they wanted to know about their stuff, because they learned, and I didn't have to fix the same stuff twice, for the same guy. I always had more business than I could work, and I usually sent the Apprentice's down on the small stuff, after they had worked with me, for six months, out in the field. I have trained a lot of Marine Techs, over the years, and as we are a Dying Breed, Many are doing other things in RF Communications than Marine work these days. I used to be able to count the Quality Marine Radiomen on the West Coast and North Pacific on two hands. NOW it is down to One hand, and MF/HF Marine RadioMen... well I can think if just (4) that I would take my rigs to, as this is now a Very Specialized Area of Marine World, and mostly obsolete, due to TracPhones, Cellular, and GMDSS. I am just happy to consult and be semi-reTired. -- Bruce in alaska add path after fast to reply |
Uniden 525 VHF and general question
Wayne.B wrote:
On Mon, 14 Dec 2009 11:57:59 -0600, brian whatcott wrote: it is not all that easy to maintain a 50 ohm impedance AND soak up most of the transmit power with salt water in a coax If the coax is soaking most of the transmit power it doesn't really matter what impeadance it is. An SWR meter will still show no reflected power, hence a 1:1 ratio. Hmmm.. that sounds a little doubtful to me. If a coax gets a short, it reflects plenty before the short. If a coax gets an open, it reflects plenty before the open.... If a coax gets a 50 ohm lossy resistance, then it soaks up all the power with no reflection. That's where I'm coming from... B |
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