Ah fairy nuff, wasn't clear the type of antennas being talked about. Understand what is being said now.
Aside there is a story that the USA for their ELF system use the gap between two islands as a slot antenna.
Googling suggests its been seriously looked at A new interpretation of the VLF impedance measurements of island slot antennas - Barr - 1980 - Radio Science - Wiley Online Library
Propagation is not quite the same as antenna performance.
I'm talking antenna performance.
Propagation is an atmospheric phenomenon.
I think we will disagree on this.
The terrain and the trees make a difference.
The closer the trees, and the less flat the terrain the more effect.
High enough, no worries.
The nature of the ground may also have an effect.
Those who work with 150ft-200ft towers are excluded.
Last edited:
I'm not sure what it is that you believe we disagree on. Nearby trees are in the near-field zone (hint: 'nearby') and hence have nothing to do with propagation (far away)? Small antennas sometimes work by inducing currents in nearby structures?bear said:
Make a difference to what? Antenna efficiency? Yes. Antenna feed impedance? Yes. Antenna radiation pattern? Yes. Propagation? No, not directly - but indirectly via the antenna radiation pattern, as power you have not radiated in a particular direction cannot propagate in that direction.
So, yes, antenna performance depends on what is near it. I never said otherwise.
Next thing we will be all agreeing is that an open Shalco switch is better than a sealed small signal relay filled with inert gas . . . .
Oh, I just realized. If its filled with argon, you are going to lose the 'airyness' of the sound, while nitrogen OTOH will definitely screw the bass up (why? because on bass notes, the surrounding gas is ionized, causing some of the signal energy to leak away). Furthermore, relays also provide capacitive feedback, and we all know where that leads: complete destruction of the sound field aka sound stage. Remember, Martin Collums ([sp?] warned us of this 30 years ago.
On all my new designs, I am using a custom 7" motorized blade switch. I thought I better go one better than the 'sandman' with his chain driven motorized Shalco. Scheduled for release in December!
Anyway, just had to bring some objectivity to this discussion again - hope you all accept it, and my expertise in these matters, in the spirit it is offered.
More l8r
Oh, I just realized. If its filled with argon, you are going to lose the 'airyness' of the sound, while nitrogen OTOH will definitely screw the bass up (why? because on bass notes, the surrounding gas is ionized, causing some of the signal energy to leak away). Furthermore, relays also provide capacitive feedback, and we all know where that leads: complete destruction of the sound field aka sound stage. Remember, Martin Collums ([sp?] warned us of this 30 years ago.
On all my new designs, I am using a custom 7" motorized blade switch. I thought I better go one better than the 'sandman' with his chain driven motorized Shalco. Scheduled for release in December!
Anyway, just had to bring some objectivity to this discussion again - hope you all accept it, and my expertise in these matters, in the spirit it is offered.
More l8r
Last edited:
I think I confused the discussion. Mainly as my reference point is 1GHz and up and 20m off the ground. At those frequencies far field comes a lot quicker, and trees most defiantly affect propagation. You can even see the changes in call drop stats on phone networks in spring and autumn/fall due to those pesky leaves.
But now have the right paradigm so understand where everyone is coming from.
But now have the right paradigm so understand where everyone is coming from.
It doesn't work that way there is no local .2V inside a connector, there is .2V across your metal to metal connection i.e. completely corroded no metal to metal contact at all. ANY metal to metal contact left shorts the diode just like my experiment.
Do you read and understand these or just look at the titles.
Audio connections normally are formed with significant mechanical force. All IC's and discrete devices are made with lots of mechanical connections of differing metals how could you even make an AP? Did you see the connectors on that pico-voltmeter, you crank them down HARD.
Try again copper - oxide - copper means no metal to metal mechanical connection left, any solid even partial metal to metal connection shorts out any diode action in normal audio use. If that was not the case you could reproduce these "distortions" over the entire dynamic range of the signals of interest.
Last edited:
Somehow this seems like a loaded question. Some people confidently believe they "know" things that probably aren't physically true. In some of those cases, if they ever succeed in tracking down the physical cause, they may find that now they "know" differently. If not, then a mystery may remain, for them at least. Maybe not for somebody who had the same thing happen and figured out the cause accurately and not inconsistent with well established physics.
Last edited:
What, full of vacuum quantum energy? That would sound awful.
Our new amp is filled with high quality beeswax...
OK, now I understand where you were coming from. I assumed HF; you assumed UHF/microwave. The original remark by 'bear' was about choosing trees for antenna supports, so HF is more likely as trees move too much to act as a good antenna support for much higher frequencies.billshurv said:
I guess as this site is US-dominated the rude work checker uses US ideas about rude words.gpauk said:
When I lived in London I often saw American tourists on the Northern Line giggle and look embarrassed when the announcer said "this train is for ****fosters". "Honey, did he really say that?".
I was more thinking of a helium release valve, to complement the matching divers watch.
(as should be common knowledge, owners of fancy diver watches in 18k gold never go beyond jacuzzi depth)
- Status
- Not open for further replies.