Re: long antenna

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From	jimp@specsol.spam.sux.com
Newsgroups	sci.physics
Subject	Re: long antenna
Date	Sun, 22 Nov 2015 23:16:22 -0000
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Sender	Jim Pennino <jimp@mail.specsol.com>
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gilber34 <fafa@invalid.com> wrote:
> On 11/19/2015 12:44 PM, jimp@specsol.spam.sux.com wrote:
>> gilber34 <fafa@invalid.com> wrote:
>>> On 11/18/2015 11:29 PM, jimp@specsol.spam.sux.com wrote:
>>>> gilber34 <fafa@invalid.com> wrote:
>>>>> On 11/18/2015 5:15 PM, jimp@specsol.spam.sux.com wrote:
>>>>>> gilber34 <fafa@invalid.com> wrote:
>>>>>>> On 11/18/2015 3:56 PM, Thomas 'PointedEars' Lahn wrote:
> <snip>
> 
>>>>> one can use an antenna with a preamp and forget matching, however the
>>>>> preamp will be a mixer, with the LO supplied by FM, TV stations or other
>>>>> if around, providing inteference.
>>>>
>>>> Total nonnsense.
>>>
>>> not at all, the typical tradeoff in designing preamps, how much gain, in
>>> how much selectivity (bandwidth), how much NF.
>>> Typical in the below 30MHz RF preamps is no antenna matching, other
>>> factors dominate.
>>
>> Nope.
> 
> have to match transmitter,  below 30 MHz receiver preamps not much need 
> at all.

Preamps have nothing to do with transmitters.

A switchable preamp is very handy; switch in it when signal levels are
low and out when there are strong signals that would cause overload.

>>>>
>>>> Mixing requires a non-linear device and preamps are built to be linear
>>>> devices.
>>>
>>> preamps are linear only in a range, outside this range all preamps are
>>> mixers.  And even in their linear range, they also provide gain to other
>>> signals in their bandwidth, which also cause following stages to be over
>>> driven, to become mixers.
>>
>> Arm waving.
> 
> this is stuff experienced RF designers know, not the Hams, or amateur 
> radio people what is left of them.

This is very basic RF that you can find in the Radio Amateurs Handbook.

I suggest you read it.

>>>
>>> If you put a +20dB preamp on your FM radio, it will trash it out totally.
>>
>> This just shows you haven't a clue why one would use a preamp.
>>
> 
> so you are recommending using +20dB preamp for FM radios ?

No, I am saying you don't know what you are talking about.

>>>> Matchins still important to preamps.
>>>
>>> and so is intentional mis-matching, important to provide stability, and
>>> loading for front end filters, and finding best NF, a tradeoff
>>> typically. Depends on the band and application.
>>
>> Nope.
> 
> well, that is RF design, not amateur radio sandbox tinkering.

Nope, it is babbling word salad.

>>>>
>>>> Most of that is just nonsense.
>>>
>>> I see you are unfamiliar with FM radio.
>>> "Capture" is also closely related to "takeover gain"
>>> That is why FM sounds so much better than AM.
>>
>> Nope.
>>
>> Clueless.
>>
>> FYI, FM sounds better than AM (for broadcast) because the allowed bandwidth
>> is much higher. It has little to nothing to do with the modulation other
>> than FM is static resistant.
> 
> Why is FM "static resistant" ?  Capture effect.

Nope, it is because static is primarily AM.

> Guess you should take some time and refresh yourself.

Guess you still haven't a clue what you are talking about.

>>
>>> https://www.physicsforums.com/threads/fm-modulation-capture-effect.747206/
>>>
>>>>
>>>>> he said he was listening to FM, so he is in a city,
>>>>
>>>> There are lots of FM stations outside major cities these days.
>>>
>>>>> but break out your spectrum analyser and see how huge the FM station
>>>>> power is, larger than any other, except for some TV channels
>>>>>
>>>>> I would do it and send a photo, but my analyser when last turned on, let
>>>>> out some smoke in the back, and no workie now. (smoked a resistor in the
>>>>> power section somewhere)
>>>>
>>>>
>>>> Not surprising given your level of RF knowledge.
>>>
>>> no it is a nice but older 10KHz to 22GHz Unit, easy to fix smoked
>>> resistor, but a 100#der almost a boat anker.
>>> but Troll on if you must, but you could contribute too.
>>
>> OK.
>>
>> Go buy a copy of the Radio Amateurs Handbook and read it.
>>
> 
>  that is for Amateurs, 1960's stuff, and didn't they quit printing that 
> a while back ?

Nope, it is kept up to date and is far above your demonstrated technical
level.

 

-- 
Jim Pennino

Thread

long antenna RichD <r_delaney2001@yahoo.com> - 2015-11-17 10:42 -0800
  Re: long antenna Odd Bodkin <bodkinodd@gmail.com> - 2015-11-17 12:46 -0600
    Re: long antenna Poutnik <poutnik4nntp@gmail.com> - 2015-11-17 20:10 +0100
    Re: long antenna jimp@specsol.spam.sux.com - 2015-11-17 20:28 +0000
      Re: long antenna benj <nobody@gmail.com> - 2015-11-17 16:59 -0500
    Re: long antenna Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-11-18 22:56 +0100
      Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-18 16:57 -0600
        Re: long antenna jimp@specsol.spam.sux.com - 2015-11-18 23:15 +0000
          Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-18 20:42 -0600
            Re: long antenna jimp@specsol.spam.sux.com - 2015-11-19 05:29 +0000
              Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-19 08:54 -0600
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-19 18:44 +0000
                Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-22 15:32 -0600
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-22 23:16 +0000
            Re: long antenna HVAC <mr.hvac@gmail.com> - 2015-11-19 06:59 -0800
              Re: long antenna benj <none@gmail.com> - 2015-11-19 20:02 -0500
      Re: long antenna benj <none@gmail.com> - 2015-11-19 01:36 -0500
  Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-17 13:28 -0600
  Re: long antenna "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-17 14:04 -0800
    Re: long antenna jimp@specsol.spam.sux.com - 2015-11-17 22:35 +0000
      Re: long antenna benj <nobody@gmail.com> - 2015-11-17 19:28 -0500
        Re: long antenna Timo <timo@physics.uq.edu.au> - 2015-11-17 17:18 -0800
          Re: long antenna RichD <r_delaney2001@yahoo.com> - 2015-11-24 11:39 -0800
            Re: long antenna benj <none@gmail.com> - 2015-11-24 15:12 -0500
              Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-26 09:21 -0600
                Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-26 10:05 -0600
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-26 20:05 +0000
                Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-26 18:39 -0600
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-27 01:46 +0000
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-26 19:55 +0000
            Re: long antenna jimp@specsol.spam.sux.com - 2015-11-24 20:04 +0000
              Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-24 16:33 -0600
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-24 22:58 +0000
                Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-26 09:11 -0600
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-26 19:42 +0000
                Re: long antenna "Ross A. Finlayson" <ross.finlayson@gmail.com> - 2015-11-26 11:57 -0800
                Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-26 14:52 -0600
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-26 21:12 +0000
                Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-26 18:58 -0600
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-27 01:37 +0000
                Re: long antenna benj <none@gmail.com> - 2015-11-26 23:45 -0500
                Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-27 01:01 -0600
                Re: long antenna "Ross A. Finlayson" <ross.finlayson@gmail.com> - 2015-11-26 23:31 -0800
                Re: long antenna benj <nobody@gmail.com> - 2015-11-27 11:34 -0500
                Re: long antenna "Ross A. Finlayson" <ross.finlayson@gmail.com> - 2015-11-27 09:58 -0800
                Re: long antenna benj <nobody@gmail.com> - 2015-11-27 11:46 -0500
                Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-28 16:42 -0600
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-28 22:58 +0000
                Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-30 07:46 -0600
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-30 19:01 +0000
                Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-30 14:12 -0600
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-30 20:43 +0000
                Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-30 17:41 -0600
                Re: long antenna jimp@specsol.spam.sux.com - 2015-12-01 00:15 +0000
                Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-30 20:23 -0600
                Re: long antenna jimp@specsol.spam.sux.com - 2015-12-01 06:21 +0000
                Re: long antenna benj <none@gmail.com> - 2015-11-30 15:22 -0500
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-30 20:48 +0000
                Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-30 17:16 -0600
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-30 23:52 +0000
                Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-30 19:59 -0600
                Re: long antenna jimp@specsol.spam.sux.com - 2015-12-01 02:16 +0000
                Re: long antenna benj <none@gmail.com> - 2015-11-30 19:20 -0500
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-27 18:53 +0000
              Re: long antenna benj <none@gmail.com> - 2015-11-25 00:08 -0500
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-25 06:13 +0000
  Re: long antenna "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-18 16:25 -0800
  Re: long antenna "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-19 16:08 -0800
    Re: long antenna jimp@specsol.spam.sux.com - 2015-11-20 00:40 +0000
      Re: long antenna "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-20 15:51 -0800
        Re: long antenna jimp@specsol.spam.sux.com - 2015-11-21 00:34 +0000
          Re: long antenna jmfbahciv <See.above@aol.com> - 2015-11-21 14:37 +0000
            Re: long antenna jimp@specsol.spam.sux.com - 2015-11-21 19:32 +0000
              Re: long antenna jmfbahciv <See.above@aol.com> - 2015-11-22 14:50 +0000
                Re: long antenna "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-22 11:27 -0800
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-22 19:44 +0000
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-22 19:40 +0000
                Re: long antenna jmfbahciv <See.above@aol.com> - 2015-11-23 14:13 +0000
                Re: long antenna benj <none@gmail.com> - 2015-11-23 13:00 -0500
                Re: long antenna jmfbahciv <See.above@aol.com> - 2015-11-24 13:20 +0000
                Re: long antenna benj <none@gmail.com> - 2015-11-24 13:40 -0500
                Re: long antenna jmfbahciv <See.above@aol.com> - 2015-11-25 13:44 +0000
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-23 18:47 +0000
                Re: long antenna jmfbahciv <See.above@aol.com> - 2015-11-24 13:20 +0000
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-24 19:49 +0000
                Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-24 16:36 -0600
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-24 23:00 +0000
                Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-26 16:17 -0600
                Re: long antenna jimp@specsol.spam.sux.com - 2015-11-26 23:35 +0000
        Re: long antenna benj <none@gmail.com> - 2015-11-20 20:58 -0500
    Re: long antenna benj <none@gmail.com> - 2015-11-19 20:09 -0500
  Re: long antenna "nuny@bid.nes" <Alien8752@gmail.com> - 2015-11-24 12:51 -0800
    Re: long antenna benj <none@gmail.com> - 2015-11-25 00:01 -0500
  Re: long antenna "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-25 15:36 -0800
    Re: long antenna jimp@specsol.spam.sux.com - 2015-11-25 23:51 +0000

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