5kw?
On Thursday, June 25, 2026 at 08:14:22 PM GMT+4,
<[email protected]> wrote:
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Today's Topics:
1. 5KW amp squibble (John Randall)
2. Re: 5KW amp squibble (Jim Brown)
3. Re: 5KW amp squibble (Rob Atkinson)
4. Re: 5KW amp squibble (Wes Stewart)
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Message: 1
Date: Thu, 25 Jun 2026 07:24:08 +0000 (UTC)
From: John Randall <[email protected]>
To: "[email protected]" <[email protected]>
Subject: Topband: 5KW amp squibble
Message-ID: <[email protected]>
Content-Type: text/plain; charset=UTF-8
I dont say much on this form, but this squibble awoke? something in me. Most of
you guys on top band have massive land, plots whatever, so can erect huge
antennas by comparison, perhaps now you know how most of us less fortunate have
to cope with 20ft by 20ft back yard? for our antennas. Money,country, wealth
aside,? Perhaps you should sit back and consider what those less fortunate have
to do to get a signal out, what with restrictive planning laws. There are
bigger amps out there being used, ex commercial one's too. Don't begrudge
people using large amplifiers legally, after all you gotta prove they are
running over limits or uncle sam has to.A 5kw or a 10kw amp can run clean, its
just depends on what class? the tube is running and the audio processing from
those ghetto blaster audio racks.
getting back into the shadows
73John M0ELS
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Message: 2
Date: Thu, 25 Jun 2026 02:24:58 -0700
From: Jim Brown <[email protected]>
To: [email protected]
Subject: Re: Topband: 5KW amp squibble
Message-ID:
<[email protected]>
Content-Type: text/plain; charset=UTF-8; format=flowed
On 6/25/2026 12:24 AM, John Randall via Topband wrote:
> I dont say much on this form, but this squibble awoke? something in me. Most
> of you guys on top band have massive land, plots whatever, so can erect huge
> antennas by comparison, perhaps now you know how most of us less fortunate
> have to cope with 20ft by 20ft back yard? for our antennas.
I can relate, John. Most of my 70 years as a ham was spent in towns and
cities on small lots and with little money. I had pretty good used
radios, but limited antennas. From my city lot in Chicago, it was a
struggle to work the west coast of the US, and I worked no DX at all.
Serving as the representative of the Pacific Division on ARRL's Contest
Advisory Council, I work hard to represent hams like you.
That all changed 20 years ago, when I retired and moved to 8 acres in
the Santa Cruz Mountains, where I have the station beyond my wildest
dreams.
But I remember what those early 50 years were like. And I'm also an EE
by training, and with a specialty in RFI. So I know what high power
would do in a QTH like yours -- every piece of consumer equipment in
your home and the homes of your neighbors would be turning flips when
you transmitted, so you'd face a rebellion from your neighbors. AND,
thanks to the dozens of noise sources in your home and the homes of each
of those neighbors, all you would hear would be the biggest of the
signals above their noise. And even here, noise levels have increased by
15-20 dB, depending on direction.
We can't "brute force" a solution to this. We've got to work smarter,
taking advantage of new technologies that reject noise. There are
digital modes that can average multiple transmissions of very limited
data -- callsign, signal report, QTH -- to offer more than 30 dB of
noise rejection. These are not "conversational" modes -- rather, they
use the fundamentals of communications theory that I learned baby steps
of in my senior EE courses in 1964, and that have grown exponentially in
the decades since. Early variations of these techniques are how we talk
to spacecraft launched 30 years ago to control them and download from
their instrumentation.
WSJT-X, by Nobel-laureate Joe Taylor, K1JT and a team of programmers,
combines a dozen or so digital modes for various forms of propagation.
There's one for meteor scatter, where propagation exists in short
bursts, for paths with lots of attenuation and fading, like topband.
Others optimized for tropospheric propagation on VHF/UHF. FST4 is the
one designed for propagation at LF and MF. FST4W is designed to replace
WSPR, providing a few dB greater noise immunity. Noise immunity is
increased by longer transmitting intervals and by averaging.
73, Jim K9YC
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Message: 3
Date: Thu, 25 Jun 2026 06:21:33 -0500
From: Rob Atkinson <[email protected]>
To: [email protected]
Subject: Re: Topband: 5KW amp squibble
Message-ID:
<calwd7z4k05wpm8-vdop7g3wnxfswun6fvvklsyfbkutnqom...@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"
>every piece of consumer equipment in your home and the homes of your neighbors
>would be turning flips when you transmitted,
That's not really as big of a problem now compared to 10 or 20 years
ago. Almost no one gets OTA TV. Most people are on cell phones, or
VOIP via shielded cable. People don't listen to music with stereos
and speakers now except for old farts like me. Most people use ear
buds and spotify. They watch TV streams over internet. Since almost
everything now is digital, fiber optic, bluetooth, wifi, you can run
QRO on medium wave and HF and not worry about a torch carrying mob at
your door. It's really a good time to be a ham as far as that's
concerned.
73
Rob
K5UJ
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Message: 4
Date: Thu, 25 Jun 2026 13:09:40 +0000 (UTC)
From: Wes Stewart <[email protected]>
To: "[email protected]" <[email protected]>, Rob Atkinson
<[email protected]>
Subject: Re: Topband: 5KW amp squibble
Message-ID: <[email protected]>
Content-Type: text/plain; charset=UTF-8
I still have three vehicles with AM radios.? I watch OTA TV, when my cell
service goes out I call them up on my wired landline to report it and then pop
a CD into the changer and listen to it on my multi-speaker audio system.
While I am typing this on my office computer my radio in the shack just worked
3G0YM on 20-meter FT8.
On Thursday, June 25, 2026 at 04:26:10 AM MST, Rob Atkinson via Topband
<[email protected]> wrote:
>every piece of consumer equipment in your home and the homes of your
>neighbors would be turning flips when you transmitted,
That's not really as big of a problem now compared to 10 or 20 years
ago.? Almost no one gets OTA TV.? Most people are on cell phones, or
VOIP via shielded cable.? People don't listen to music with stereos
and speakers now except for old farts like me.? Most people use ear
buds and spotify.? They watch TV streams over internet.? Since almost
everything now is digital, fiber optic, bluetooth, wifi, you can run
QRO on medium wave and HF and not worry about a torch carrying mob at
your door.? It's really a good time to be a ham as far as that's
concerned.
73
Rob
K5UJ
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