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The inefficiency of short antennae compared to long antennae, as previously discussed.
"Brian Reay" wrote in message
... Nor do I have a brother who is a milkman, or one who has ever been a milkman. "Have"? Sophistry. He's dead, isn't he? |
The inefficiency of short antennae compared to long antennae, as previously discussed.
"gareth" wrote in message
... But your behaviour and language is as one from the working class and not as one from the degree-educated minority. Eh? By "working class" do you mean anyone that works for their living? That infers your "degree-educated minority" are all unemployed. -- ;-) .. 73 de Frank Turner-Smith G3VKI - mine's a pint. .. http://turner-smith.co.uk |
The inefficiency of short antennae compared to long antennae, as previously discussed.
"Clod's Conscience" wrote in message
... On Wed, 22 Oct 2014 19:49:25 +0100, Ian Jackson wrote: If someone has a big nose, I would have thought that shouting "You've got a big nose!" at them would fairly be classed as 'abuse' (despite being true). So if I told Gareth he had a fat arse and a face like a bulldog chewing a wasp, it would be abuse? Abusive to bulldogs, maybe. (and wasps) -- ;-) .. 73 de Frank Turner-Smith G3VKI - mine's a pint. .. http://turner-smith.co.uk |
The inefficiency of short antennae compared to long antennae, as previously discussed.
"gareth" wrote in message
... "Brian Reay" wrote in message ... Nor do I have a brother who is a milkman, or one who has ever been a milkman. "Have"? Sophistry. He's dead, isn't he? Brian, is it possible that you still have a chip on your shoulder about being sent to a technical school for chippies and blacksmiths, and not to a grammar school for the intellectually elite, which is why you lash out with personal remarks in every post in every NG that you frequent? |
The inefficiency of short antennae compared to long antennae,as previously discussed.
On 10/22/2014 1:06 PM, gareth wrote:
"John S" wrote in message ... In what way have I been abusive, Gareth? See below. It seems to me that you are a lost and lonely soul and are seeking some attention. I don't believe that statement is considered abuse. |
The inefficiency of short antennae compared to long antennae,as previously discussed.
On Wed, 22 Oct 2014 21:33:03 +0000, Brian Reay wrote:
"Wayne" wrote: "Steve" wrote in message ... On Wed, 22 Oct 2014 17:36:31 +0100, FranK Turner-Smith G3VKI wrote: "Wayne" wrote in message ... "gareth" wrote in message ... Try this ... http://farside.ph.utexas.edu/teachin...es/node94.html This is one of a series of lectures by a prof at Texas Uni. In fact, if you go right back to the home page of http://farside.ph.utexas.edu/teaching, this leads to a most excellent revision of the necessary EM theories, and, briefly glancing thereto, the post grad stuff even exceeds my current interest and knowledge. I'm fairly sure now that this area is where I came across the governing formula that I alluded to recently in this NG when doing my own revision previously in 2005, although the URLs and lecture node numbers have changed since then. When I get time, I'll browse through the links. However, back to your original assertion that your theory has short antennas as being inefficient compared with longer antennas (I'm assuming you are talking half wave dipoles and such). If 10 watts is delivered to a short antenna, where does it go if it is not radiated just as well as 10 watts delivered to a long antenna? Dissipated as heat? # Probably proportionately more will be lost as heat as a very short # antenna will be a low impedance, therefore current, driven job and I sq*R # losses within the antenna will play their part. Apart from those # additional losses, it should radiate all that is left, ... I think. Actually no. The loss resistance tends to be dwarfed by the radiation resistance, so losses in the antenna are not the problem. I think you're missing the point I was making. That is; as antennas become shorter and shorter, an ever increasing amount is lost as I^2 R. In normal antennas you are correct that RR swamps I^2 R but as antennas get shorter and shorter I^ R becomes a much larger factor as the intrinsic antenna impedance drops and drops whilst the current rises and rises. The problem is matching. A small antenna has a narrow BW so you tend to need a matching system. That is where the losses will be, plus in any feeder. Of course, if you only need a narrow BW and can arrange a low loss feeder plus load the pa correctly, then pa is happy, low feeder loss, the RF gets to the antenna. The antenna RrRL so antenna loss is low. Yes, matching becomes a serious issue but that is not what we are talking about. RF has only one place left to go, to be radiated. Agreed. |
The inefficiency of short antennae compared to long antennae, as previously discussed.
Brian Morrison wrote:
On Thu, 23 Oct 2014 17:36:53 -0000 wrote: Quite often I find I haven't a clue what people are talking about, mostly when it is just casual conversation between the characters. It's that old 2 nations divided by a common language thing again. It takes time to tune in to the nuances of conversation in different places. Well, I have managed to figure out bangers, mushy peas, quid, jumble, and that going to surgery is just a visit to the doctor and not the major event it is here. -- Jim Pennino |
The inefficiency of short antennae compared to long antennae, as previously discussed.
In message , Brian
Morrison writes On Thu, 23 Oct 2014 17:36:53 -0000 wrote: Quite often I find I haven't a clue what people are talking about, mostly when it is just casual conversation between the characters. It's that old 2 nations divided by a common language thing again. It takes time to tune in to the nuances of conversation in different places. These days, although I have good hearing, I find it often helps a lot to have the subtitle (closed caption) text turned on. -- Ian |
The inefficiency of short antennae compared to long antennae, as previously discussed.
"Ian Jackson" wrote in message
... These days, although I have good hearing, I find it often helps a lot to have the subtitle (closed caption) text turned on. That's because of the woolly-voiced productions that started with Jamaica Inn! (and will continue with Spartacus tonight) |
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