Author Topic: MLA-30+ (refrain)  (Read 5068 times)

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Offline Co6aka

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Re: MLA-30+ (refrain)
« Reply #25 on: April 10, 2021, 05:22:14 pm »
it is impossible to get constant Noise Floor figures from any of them

You must have a controlled environment; either a anechoic chamber, or replace the loop element with a discrete R/L/C "simulation" of the loop element's characteristics and then enclose the amp in a RF-tight enclosure. Anything else is an exercise in time wasting.
Co6aka says, "BARK! and you have no idea how humans will respond."
 

Offline vinlove

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Re: MLA-30+ (refrain)
« Reply #26 on: April 10, 2021, 08:22:44 pm »
it is impossible to get constant Noise Floor figures from any of them

You must have a controlled environment; either a anechoic chamber, or replace the loop element with a discrete R/L/C "simulation" of the loop element's characteristics and then enclose the amp in a RF-tight enclosure. Anything else is an exercise in time wasting.

Even if the testings are done strictly controlled way, they are still meaningless and waste of  time.  Because in  real uses of the antennas, no one will have the antennas set up in the controlled way.  The antennas will be set up out there somewhere under all the influences of the weather, time of the day, monthly and seasonal changes.  But most critically, no one can control the actual propagational condition, which will be affecting the noise level dramatically.

And what is more, all the other devices in the chain generate their own noise too = the receivers, the power lines, and the feeders picking up the noise ... blah blah, and they all affect and contribute to the noise level of the final output signal.
« Last Edit: April 10, 2021, 08:28:13 pm by vinlove »
 

Offline Co6aka

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Re: MLA-30+ (refrain)
« Reply #27 on: April 13, 2021, 02:59:50 pm »
...in  real uses of the antennas...

"Real use" isn't what's being tested/analyzed, and is a completely different subject. The basis is the amplifier, and its performance is what's being tested/analyzed. "Real use" is irrelevant; if an amplifier's NF is 3dB then it will be 3dB wherever it's mounted, and the same for its other parameters, intercepts, etc.  Professionally, that's why antenna "testings are done strictly controlled way" in a anechoic chamber and not in "real use."

Everything else you mentioned, weather, time of the day, monthly and seasonal changes, propagation, QRN, QRM, and so on is relatively irrelevant.  Except, that a factor many amplifier designers fail to account for is the temperature range the amplifier will be subjected to; temperature compensation must be included in the design, both circuit and mechanical. (Potting compounds that expand and contract at amounts and rates significantly different from the components/PCB they enclose, for example.)
Co6aka says, "BARK! and you have no idea how humans will respond."
 

Offline vinlove

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Re: MLA-30+ (refrain)
« Reply #28 on: April 13, 2021, 04:25:04 pm »
...in  real uses of the antennas...

"Real use" isn't what's being tested/analyzed, and is a completely different subject. The basis is the amplifier, and its performance is what's being tested/analyzed. "Real use" is irrelevant; if an amplifier's NF is 3dB then it will be 3dB wherever it's mounted, and the same for its other parameters, intercepts, etc.  Professionally, that's why antenna "testings are done strictly controlled way" in a anechoic chamber and not in "real use."

Everything else you mentioned, weather, time of the day, monthly and seasonal changes, propagation, QRN, QRM, and so on is relatively irrelevant.  Except, that a factor many amplifier designers fail to account for is the temperature range the amplifier will be subjected to; temperature compensation must be included in the design, both circuit and mechanical. (Potting compounds that expand and contract at amounts and rates significantly different from the components/PCB they enclose, for example.)

Hmmm.. I disagree with you totally.

The whole point of the antennas, and testings are for the "REAL" use.   No one is designing antennas just to test them?  No one will buy antennas for just testing and analysing them? The real point is to use them in real listening the signals.

if testing and modifying is not going to improve or help in real use of the antenna, then it is just pointless. You would better putting the time for something else which is more productive?

In the beginning, I was not sure. Yes, it might improve and help the real listening by the modifications. But after many weeks of observation, testing with different antennas, they all change under the factors. So it was not really going to make any significant difference.
« Last Edit: April 13, 2021, 04:27:38 pm by vinlove »
 

Offline Co6aka

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Re: MLA-30+ (refrain)
« Reply #29 on: April 15, 2021, 01:08:25 pm »
I disagree with you totally.

Actually then, you disagree with the entire industry. :horse: To test a parameter it must be isolated from others and the effects of others, and then other parameters are introduced to test for interactions.

But after many weeks of observation...

In the audiophile world you have the same subjective analyses because what matters isn't what's real but what's believed. If what you believe makes you "happy" then of course be happy. Meanwhile though, it's still what it is because it ain't something else. :-DMM Blessed are those who believe without having seen the measurements.
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Offline vinlove

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Re: MLA-30+ (refrain)
« Reply #30 on: April 15, 2021, 01:51:35 pm »
double post (Deleted)
« Last Edit: April 15, 2021, 01:53:29 pm by vinlove »
 

Offline vinlove

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Re: MLA-30+ (refrain)
« Reply #31 on: April 15, 2021, 01:52:24 pm »

I agree with the tests must be carried out in strictly controlled environment and ways.
And I do trust and believe in the measurements from the testings and interpretations and conclusions from it too.

What I did not agree was that, the modification of MLA30 and MLA30+ power supply will make the antenna quieter, and therefore better performing.

Even the best active loops with super high quality PSUs and parts and all, sometimes got noisy and poor sounding depending on the condition, and  the way it is setup, where it is set up, and kind of radios it was connected to etc etc. Too many factors have implication influencing the performance antennas, so I was thinking that any modifications on the PSU of MLA30 would not greatly improve or sound any better than it is from the factory spec.
And unless I was to write scientific paper submitting to some institution, I did not need going through any measurements or screen captures of my observations and testings.  Just a video which demonstrates which antenna sounds better for receiving DX signal and explanation would be enough.

I was just updating my conclusion as promised from the earlier posts in the thread. :)
 


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