Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss
Re: What happens if you exceed the wattage of a transmitter antenna
274 views
Skip to first unread message
Fox's Mercantile
Mar 23, 2021, 10:22:44 PM3/23/21
to
On 3/23/21 6:22 PM, Unlisted wrote:
> I have a FM OMNI antenna hooked to a 30 watt fm transmitter. The antenna
> is rated at 50 watts max. What would happen if i ran a 60 watt
> transmitter thru it? Or 100 watts? Will the antenna melt or what?
Two things limit the power handling capability of an antenna.
The RF current abilities of any coils of wire, and the RF voltage
breakdown rating of any insulation.
As to whether or not it would put up with 60 or 100 watts, that's
entirely dependent on how well (over designed) that antenna was
made.
--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com
> I have a FM OMNI antenna hooked to a 30 watt fm transmitter. The antenna
> is rated at 50 watts max. What would happen if i ran a 60 watt
> transmitter thru it? Or 100 watts? Will the antenna melt or what?
Two things limit the power handling capability of an antenna.
The RF current abilities of any coils of wire, and the RF voltage
breakdown rating of any insulation.
As to whether or not it would put up with 60 or 100 watts, that's
entirely dependent on how well (over designed) that antenna was
made.
--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com
Phil Allison
Mar 24, 2021, 12:31:32 AM3/24/21
to
Fox's Mercantile wrote:
---------------------------------------
50 watts at 50 ohms = 50V rms .
..... Phil
---------------------------------------
> :
> > I have a FM OMNI antenna hooked to a 30 watt fm transmitter. The antenna
> > is rated at 50 watts max. What would happen if i ran a 60 watt
> > transmitter thru it? Or 100 watts? Will the antenna melt or what?
>
> Two things limit the power handling capability of an antenna.
> The RF current abilities of any coils of wire, and the RF voltage
> breakdown rating of any insulation.
>
** Ain't it more likely to be a user safety issue ?
> > I have a FM OMNI antenna hooked to a 30 watt fm transmitter. The antenna
> > is rated at 50 watts max. What would happen if i ran a 60 watt
> > transmitter thru it? Or 100 watts? Will the antenna melt or what?
>
> Two things limit the power handling capability of an antenna.
> The RF current abilities of any coils of wire, and the RF voltage
> breakdown rating of any insulation.
>
50 watts at 50 ohms = 50V rms .
..... Phil
John Robertson
Mar 24, 2021, 1:41:48 AM3/24/21
to
John ;-#)#
Mike Coon
Mar 24, 2021, 6:04:02 AM3/24/21
to
In article <e9ydnepOVOCJTMf9...@giganews.com>,
sp...@flippers.com says...
But then pigeon shit on the antenna might lead to discovering Cosmic
microwave background radiation
https://en.wikipedia.org/wiki/Cosmic_microwave_background ...
sp...@flippers.com says...
microwave background radiation
https://en.wikipedia.org/wiki/Cosmic_microwave_background ...
Ralph Mowery
Mar 24, 2021, 12:47:12 PM3/24/21
to
In article <494d4ddc-4d84-4291...@googlegroups.com>,
palli...@gmail.com says...
and they will have a limit of voltage and current .
Some antennas can heat up enough (usually the coils) to melt out the
plastic parts seperating the elements.
Anyway it is usually the components that make up the antenna that
determin how much power they will withstand.
Too much power and you either get a voltage breakdown of the components
or a heat melt down of the components, or a combination of both.
palli...@gmail.com says...
> :
> > > I have a FM OMNI antenna hooked to a 30 watt fm transmitter. The antenna
> > > is rated at 50 watts max. What would happen if i ran a 60 watt
> > > transmitter thru it? Or 100 watts? Will the antenna melt or what?
> >
> > Two things limit the power handling capability of an antenna.
> > The RF current abilities of any coils of wire, and the RF voltage
> > breakdown rating of any insulation.
> >
>
> ** Ain't it more likely to be a user safety issue ?
>
> 50 watts at 50 ohms = 50V rms .
>
>
>
Just thought of one more issue. Some antennas have capacitors in them
> > > I have a FM OMNI antenna hooked to a 30 watt fm transmitter. The antenna
> > > is rated at 50 watts max. What would happen if i ran a 60 watt
> > > transmitter thru it? Or 100 watts? Will the antenna melt or what?
> >
> > Two things limit the power handling capability of an antenna.
> > The RF current abilities of any coils of wire, and the RF voltage
> > breakdown rating of any insulation.
> >
>
> ** Ain't it more likely to be a user safety issue ?
>
> 50 watts at 50 ohms = 50V rms .
>
>
>
and they will have a limit of voltage and current .
Some antennas can heat up enough (usually the coils) to melt out the
plastic parts seperating the elements.
Anyway it is usually the components that make up the antenna that
determin how much power they will withstand.
Too much power and you either get a voltage breakdown of the components
or a heat melt down of the components, or a combination of both.
Phil Allison
Mar 24, 2021, 5:41:32 PM3/24/21
to
Ralph Mowery wrote:
==================
.... Phil
==================
>
> > > Two things limit the power handling capability of an antenna.
> > > The RF current abilities of any coils of wire, and the RF voltage
> > > breakdown rating of any insulation.
> > >
> > ** Ain't it more likely to be a user safety issue ?
> >
> > 50 watts at 50 ohms = 50V rms .
> >
> >
> Just thought of one more issue. Some antennas have capacitors in them
> and they will have a limit of voltage and current .
>
> Some antennas can heat up enough (usually the coils) to melt out the
> plastic parts seperating the elements.
>
** The makers have experience with such failures and set a safe limit to prevent complaints.
> > > Two things limit the power handling capability of an antenna.
> > > The RF current abilities of any coils of wire, and the RF voltage
> > > breakdown rating of any insulation.
> > >
> > ** Ain't it more likely to be a user safety issue ?
> >
> > 50 watts at 50 ohms = 50V rms .
> >
> >
> Just thought of one more issue. Some antennas have capacitors in them
> and they will have a limit of voltage and current .
>
> Some antennas can heat up enough (usually the coils) to melt out the
> plastic parts seperating the elements.
>
.... Phil
Ralph Mowery
Mar 24, 2021, 9:14:00 PM3/24/21
to
In article <599bdc13-5c2c-4ae3...@googlegroups.com>,
palli...@gmail.com says...
Around 1980 some hams were sending radio teletype using around 500 watts
into trap beams and melting out the traps. The antennas were rated for
the full power limit of over 1000 watts. However as it turned out the
1000 wats was for peak power of sideband and not continious power that
was being sent to the antenna. The antenna companies had to revise
their specifications.
palli...@gmail.com says...
>
>
> ** The makers have experience with such failures and set a safe limit to prevent complaints.
>
>
>
>
Sometimes they do, some times they don't.
>
> ** The makers have experience with such failures and set a safe limit to prevent complaints.
>
>
>
>
Around 1980 some hams were sending radio teletype using around 500 watts
into trap beams and melting out the traps. The antennas were rated for
the full power limit of over 1000 watts. However as it turned out the
1000 wats was for peak power of sideband and not continious power that
was being sent to the antenna. The antenna companies had to revise
their specifications.
Phil Allison
Mar 24, 2021, 10:28:28 PM3/24/21
to
Ralph Mowery wrote:
=================
> >
> > ** The makers have experience with such failures and set a safe limit to prevent complaints.
> >
> Sometimes they do, some times they don't.
>
> Around 1980 some hams were sending radio teletype using around 500 watts
> into trap beams and melting out the traps. The antennas were rated for
> the full power limit of over 1000 watts. However as it turned out the
> 1000 wats was for peak power of sideband and not continious power that
> was being sent to the antenna. The antenna companies had to revise
> their specifications.
>
** Just shows that experience comes first.
** Once upon a time loudspeaker makers rated their products power handling based on normal home usage - even if used with a guitar amplifier. Then " hard rock " was invented and blew that method out of the water.
..... Phil
=================
> >
> > ** The makers have experience with such failures and set a safe limit to prevent complaints.
> >
> Sometimes they do, some times they don't.
>
> Around 1980 some hams were sending radio teletype using around 500 watts
> into trap beams and melting out the traps. The antennas were rated for
> the full power limit of over 1000 watts. However as it turned out the
> 1000 wats was for peak power of sideband and not continious power that
> was being sent to the antenna. The antenna companies had to revise
> their specifications.
>
** Once upon a time loudspeaker makers rated their products power handling based on normal home usage - even if used with a guitar amplifier. Then " hard rock " was invented and blew that method out of the water.
..... Phil
Ralph Mowery
Mar 24, 2021, 10:36:36 PM3/24/21
to
In article <96fbdc1e-bb06-4078...@googlegroups.com>,
palli...@gmail.com says...
speaker/amplifiers were rated for close to 100 watts but powered by a
small wall wart of maybe 12 volts and 1 amp at the most and inside the
speaker was marked for around 2 watts.
palli...@gmail.com says...
>
> ** Once upon a time loudspeaker makers rated their products power handling based on normal home usage - even if used with a guitar amplifier. Then " hard rock " was invented and blew that method out of the water.
>
>
>
Talking about speakers I just love the way some computer
> ** Once upon a time loudspeaker makers rated their products power handling based on normal home usage - even if used with a guitar amplifier. Then " hard rock " was invented and blew that method out of the water.
>
>
>
speaker/amplifiers were rated for close to 100 watts but powered by a
small wall wart of maybe 12 volts and 1 amp at the most and inside the
speaker was marked for around 2 watts.
Phil Allison
Mar 24, 2021, 11:29:33 PM3/24/21
to
Ralph Mowery wrote:
==================
Except you would have to gullible fool of the decade to believe it.
...... Phil
==================
>
> >
> > ** Once upon a time loudspeaker makers rated their products power handling based on normal home usage - even if used with a guitar amplifier. Then " hard rock " was invented and blew that method out of the water.
> >
> >
> >
> Talking about speakers I just love the way some computer
> speaker/amplifiers were rated for close to 100 watts but powered by a
> small wall wart of maybe 12 volts and 1 amp at the most and inside the
> speaker was marked for around 2 watts.
>
** Seems there was no law preventing such nonsense.
> >
> > ** Once upon a time loudspeaker makers rated their products power handling based on normal home usage - even if used with a guitar amplifier. Then " hard rock " was invented and blew that method out of the water.
> >
> >
> >
> Talking about speakers I just love the way some computer
> speaker/amplifiers were rated for close to 100 watts but powered by a
> small wall wart of maybe 12 volts and 1 amp at the most and inside the
> speaker was marked for around 2 watts.
>
Except you would have to gullible fool of the decade to believe it.
...... Phil
Fox's Mercantile
Mar 25, 2021, 12:43:33 AM3/25/21
to
On 3/24/21 10:29 PM, Phil Allison wrote:
> ** Seems there was no law preventing such nonsense.
>
> Except you would have to gullible fool of the decade to believe it.
E = I x R and P = E x I.
> ** Seems there was no law preventing such nonsense.
>
> Except you would have to gullible fool of the decade to believe it.
If you don't know/understand this, you have no idea of
what things are capable or incapable of.
Ralph Mowery
Mar 25, 2021, 12:24:02 PM3/25/21
to
In article <sdidnejD6epxicH9...@giganews.com>,
jda...@att.net says...
There is a 'music'rating for the amplifier/speakers. Seems to sort of
being related to radar power. You pulse the microwave device with a
few micro seconds of power several times a second and get a peak power
of many thousand of watts, but the average power is just 10 watts.
jda...@att.net says...
> n 3/24/21 10:29 PM, Phil Allison wrote:
> > ** Seems there was no law preventing such nonsense.
> >
> > Except you would have to gullible fool of the decade to believe it.
>
> E = I x R and P = E x I.
>
> If you don't know/understand this, you have no idea of
> what things are capable or incapable of.
>
>
It is not so much the law of P = E x I, but the way it is applied.
> > ** Seems there was no law preventing such nonsense.
> >
> > Except you would have to gullible fool of the decade to believe it.
>
> E = I x R and P = E x I.
>
> If you don't know/understand this, you have no idea of
> what things are capable or incapable of.
>
>
There is a 'music'rating for the amplifier/speakers. Seems to sort of
being related to radar power. You pulse the microwave device with a
few micro seconds of power several times a second and get a peak power
of many thousand of watts, but the average power is just 10 watts.
Tom Del Rosso
Mar 26, 2021, 5:45:37 PM3/26/21
to
Mike Coon wrote:
>
> But then pigeon shit on the antenna might lead to discovering Cosmic
> microwave background radiation
> https://en.wikipedia.org/wiki/Cosmic_microwave_background ...
That doesn't mention pigeons or birds. I vaguely remember there was a
>
> But then pigeon shit on the antenna might lead to discovering Cosmic
> microwave background radiation
> https://en.wikipedia.org/wiki/Cosmic_microwave_background ...
connection to the need to clean out the horns, but it would seem to be
irrelevant since they would have detected the radiation anyway.
--
Defund the Thought Police
Mike Coon
Mar 27, 2021, 4:29:42 PM3/27/21
to
In article <s3lkls$pml$1...@dont-email.me>, fizzbintuesday@that-google-
mail-domain.com says...
Ah, maybe the pigeon shit angle is a physics equivalent of an urban
myth. I believe it was the temperature spectrum of the radiation that
had to be determined, but I may actually read that article...
mail-domain.com says...
myth. I believe it was the temperature spectrum of the radiation that
had to be determined, but I may actually read that article...
Phil Hobbs
Mar 29, 2021, 5:26:08 PM3/29/21
to
started looking for any possible terrestrial noise sources. Bird
droppings are a lossy dielectric among their other less pleasant
properties, so P&W cleaned their horn antenna carefully, calibrated the
receiver, and so on, but the noise was still there.
There's still science today that's done that carefully, but I fear it
has gotten a lot less common. (Certainly the quality of papers I get
sent to review has tanked in the last 25 years or so--and yes, it's the
same journals.)
Cheers
Phil Hobbs
0 new messages