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Small transmitter antenna
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Gareth Magennis
Feb 21, 2018, 1:37:15 PM2/21/18
to
OK, so I have one of these to repair, which is missing the "tail" antenna on
the transmitter.
http://www.samsontech.com/samson/products/wireless-systems/airline/airline-ag1/
Now I know very little about RF, antennae etc.
I can't get a replacement antenna for this, so how feasible would it be to
make one?
I assume this will be a fine coil of wire covered in rubber, e.g. a tiny
rubber ducky?
Or could you just attach a long wire and roll/pack it up and attach the blob
to the guitar/guitarist?
Cheers,
Gareth.
the transmitter.
http://www.samsontech.com/samson/products/wireless-systems/airline/airline-ag1/
Now I know very little about RF, antennae etc.
I can't get a replacement antenna for this, so how feasible would it be to
make one?
I assume this will be a fine coil of wire covered in rubber, e.g. a tiny
rubber ducky?
Or could you just attach a long wire and roll/pack it up and attach the blob
to the guitar/guitarist?
Cheers,
Gareth.
Pat
Feb 21, 2018, 2:08:19 PM2/21/18
to
piece of wire. The length should be the about the same as the
original. The length would be similar to the length of the antennas
on the base unit.
Ralph Mowery
Feb 21, 2018, 2:10:40 PM2/21/18
to
In article <p%ijC.119756$3X6....@fx22.am4>,
soundser...@outlook.com says...
It would help to know the frequency range this operates on. Looks to be
about 6 inches of wire. If it is operating close to 450 MHz, then about
6 inches of wire is all that is needed. Measure the antenna on the
receiver and use a piece of wire that long.
soundser...@outlook.com says...
about 6 inches of wire. If it is operating close to 450 MHz, then about
6 inches of wire is all that is needed. Measure the antenna on the
receiver and use a piece of wire that long.
Gareth Magennis
Feb 21, 2018, 2:20:54 PM2/21/18
to
"Ralph Mowery" wrote in message
news:MPG.34f78e223...@news.east.earthlink.net...
From the manual:
It operates in the uncrowded 801 – 805, 863 – 865 MHz UHF frequency range
Gareth.
Ralph Mowery
Feb 21, 2018, 2:50:05 PM2/21/18
to
In article <lEjjC.376107$Nt6.1...@fx43.am4>,
soundser...@outlook.com says...
>
>
>
>
In that case the antenna should be about 3 1/4 to 3 1/2 inches long. If
you are using wire that is insulated, just make it 3 1/4 inches.
That is probably close to the origional length.
That makes it a 1/4 of an electrical wavelength long.
For a low power short range piece of equipment, I doubt it makes much
difference on how long it is, from 3 inchs to a foot long.
soundser...@outlook.com says...
>
> It would help to know the frequency range this operates on. Looks to be
> about 6 inches of wire. If it is operating close to 450 MHz, then about
> 6 inches of wire is all that is needed. Measure the antenna on the
> receiver and use a piece of wire that long.
>
>
> *************************************
>
>
>
> From the manual:
>
> It operates in the uncrowded 801 ? 805, 863 ? 865 MHz UHF frequency range
> It would help to know the frequency range this operates on. Looks to be
> about 6 inches of wire. If it is operating close to 450 MHz, then about
> 6 inches of wire is all that is needed. Measure the antenna on the
> receiver and use a piece of wire that long.
>
>
> *************************************
>
>
>
> From the manual:
>
>
>
>
>
In that case the antenna should be about 3 1/4 to 3 1/2 inches long. If
you are using wire that is insulated, just make it 3 1/4 inches.
That is probably close to the origional length.
That makes it a 1/4 of an electrical wavelength long.
For a low power short range piece of equipment, I doubt it makes much
difference on how long it is, from 3 inchs to a foot long.
Gareth Magennis
Feb 21, 2018, 3:16:44 PM2/21/18
to
"Ralph Mowery" wrote in message
OK, so the "antenna" is just a piece of wire then.
Blimey.
Gareth.
Gareth Magennis
Feb 21, 2018, 3:19:54 PM2/21/18
to
"Ralph Mowery" wrote in message
Thanks, Ralph, you have made my day.
I thought it was much more complicated than a piece of wire.
Gareth.
Terry Schwartz
Feb 21, 2018, 3:38:47 PM2/21/18
to
It can be, this is a topic that of late is near and dear to my career.
Antennas are a science to themselves. Any piece of wire can be an antenna, but if you want efficiency and range, things get a *lot* more complicated quickly.
It's far too broad a topic to cover here, and there is plenty written about it on the web (not all of which is correct). It's safe to say that for your application, a hunk of wire is sufficient.
Terry
Antennas are a science to themselves. Any piece of wire can be an antenna, but if you want efficiency and range, things get a *lot* more complicated quickly.
It's far too broad a topic to cover here, and there is plenty written about it on the web (not all of which is correct). It's safe to say that for your application, a hunk of wire is sufficient.
Terry
Tim R
Feb 21, 2018, 3:57:24 PM2/21/18
to
But a yagi would be fun.
Mike Coon
Feb 21, 2018, 4:11:41 PM2/21/18
to
In article <62ca1da1-31f4-472f...@googlegroups.com>,
timot...@aol.com says...
Mike.
timot...@aol.com says...
>
> But a yagi would be fun.
Good exercise, you could say...
> But a yagi would be fun.
Mike.
Ralph Mowery
Feb 21, 2018, 10:05:01 PM2/21/18
to
In article <FvkjC.177164$t77....@fx29.am4>,
soundser...@outlook.com says...
wavelength long should work fine for that application.
When you get much below 450 MHz and want an antenna shorter than around
6 inches is when it will get somewhat complicated . Then they look like
a spring under the insulation.
There is a number around 234 that if you devide it by the frequency in
MHz you will get the length of a simple 1/4 wave antenna.
soundser...@outlook.com says...
> It operates in the uncrowded 801 ? 805, 863 ? 865 MHz UHF frequency range
> >
> >
> >
> >
>
> In that case the antenna should be about 3 1/4 to 3 1/2 inches long. If
> you are using wire that is insulated, just make it 3 1/4 inches.
>
> That is probably close to the origional length.
>
> That makes it a 1/4 of an electrical wavelength long.
>
> For a low power short range piece of equipment, I doubt it makes much
> difference on how long it is, from 3 inchs to a foot long.
>
>
>
> **********************************
>
>
> Thanks, Ralph, you have made my day.
>
> I thought it was much more complicated than a piece of wire.
>
>
Simple antennas are not that complicated. Juat a piece of wire 1/4 of a
> >
> >
> >
> >
>
> In that case the antenna should be about 3 1/4 to 3 1/2 inches long. If
> you are using wire that is insulated, just make it 3 1/4 inches.
>
> That is probably close to the origional length.
>
> That makes it a 1/4 of an electrical wavelength long.
>
> For a low power short range piece of equipment, I doubt it makes much
> difference on how long it is, from 3 inchs to a foot long.
>
>
>
> **********************************
>
>
> Thanks, Ralph, you have made my day.
>
> I thought it was much more complicated than a piece of wire.
>
>
wavelength long should work fine for that application.
When you get much below 450 MHz and want an antenna shorter than around
6 inches is when it will get somewhat complicated . Then they look like
a spring under the insulation.
There is a number around 234 that if you devide it by the frequency in
MHz you will get the length of a simple 1/4 wave antenna.
Phil Allison
Feb 21, 2018, 10:43:43 PM2/21/18
to
Gareth Magennis wrote:
----------------------
> Or could you just attach a long wire and roll/pack it up and attach the blob
> to the guitar/guitarist?
>
** Err- no.
.... Phil
----------------------
>
> OK, so I have one of these to repair, which is missing the "tail" antenna on
> the transmitter.
>
> http://www.samsontech.com/samson/products/wireless-systems/airline/airline-ag1/
>
>
> Now I know very little about RF, antennae etc.
> I can't get a replacement antenna for this, so how feasible would it be to
> make one?
>
> I assume this will be a fine coil of wire covered in rubber, e.g. a tiny
> rubber ducky?
>
** While possible, it is just as likely to be a simple 1/4 wave whip.
> OK, so I have one of these to repair, which is missing the "tail" antenna on
> the transmitter.
>
> http://www.samsontech.com/samson/products/wireless-systems/airline/airline-ag1/
>
>
> Now I know very little about RF, antennae etc.
> I can't get a replacement antenna for this, so how feasible would it be to
> make one?
>
> I assume this will be a fine coil of wire covered in rubber, e.g. a tiny
> rubber ducky?
>
> Or could you just attach a long wire and roll/pack it up and attach the blob
> to the guitar/guitarist?
>
.... Phil
Phil Allison
Feb 21, 2018, 11:17:49 PM2/21/18
to
Gareth Magennis wrote:
----------------------
RF travels at 300,000 km/S so 830 MHz has a wavelength of 360mm, 25% of which gives you 90mm from the attachment point inside the Tx. A 5% "end correction" can be applied so make it 85mm.
Use wire that has a stiff cover like Teflon, to hold it out straight.
... Phil
----------------------
>
> From the manual:
>
> It operates in the uncrowded 801 – 805, 863 – 865 MHz UHF frequency range
>
** Normally a straight, 1/4 wave length whip antenna does the job well. Helically wound antennas (rubber duckies) are not better, only shorter and less efficient. I note the owners manual says the antennas are 1/4 wave.
> From the manual:
>
> It operates in the uncrowded 801 – 805, 863 – 865 MHz UHF frequency range
>
RF travels at 300,000 km/S so 830 MHz has a wavelength of 360mm, 25% of which gives you 90mm from the attachment point inside the Tx. A 5% "end correction" can be applied so make it 85mm.
Use wire that has a stiff cover like Teflon, to hold it out straight.
... Phil
gregz
Feb 22, 2018, 4:18:27 AM2/22/18
to
Greg
Gareth Magennis
Feb 22, 2018, 1:31:37 PM2/22/18
to
"Gareth Magennis" wrote in message news:p%ijC.119756$3X6....@fx22.am4...
Well a piece of wire worked a treat.
With a bit of heatshrink for strain relief at the transmitter end and
another on the end of the tail, it even looks like a proper one.
Thanks to all for the calculations and info.
Cheers,
Gareth.
Phil Allison
Feb 22, 2018, 8:41:32 PM2/22/18
to
Gareth Magennis wrote:
-----------------------
> Thanks to all for the calculations and info.
** 300 / MHz = wavelength in metres, is worth remembering.
FYI:
That AG-1 unit is about as basic as UHF FM links get, so has limited useful range and is prone to signal drops out due to multipath interference. The Tx signal can almost cancel itself after reflecting off objects and surfaces and then arriving at the Rx.
Better models have twin channel receivers, with two separated antennas, operating as a diversity pair that helps greatly to eliminate such drop outs.
.... Phil
-----------------------
>
>
> Well a piece of wire worked a treat.
>
> With a bit of heatshrink for strain relief at the transmitter end and
> another on the end of the tail, it even looks like a proper one.
>
>
** So now you know how to make a "rat tail" antenna.
>
> Well a piece of wire worked a treat.
>
> With a bit of heatshrink for strain relief at the transmitter end and
> another on the end of the tail, it even looks like a proper one.
>
>
> Thanks to all for the calculations and info.
FYI:
That AG-1 unit is about as basic as UHF FM links get, so has limited useful range and is prone to signal drops out due to multipath interference. The Tx signal can almost cancel itself after reflecting off objects and surfaces and then arriving at the Rx.
Better models have twin channel receivers, with two separated antennas, operating as a diversity pair that helps greatly to eliminate such drop outs.
.... Phil
gregz
Feb 23, 2018, 3:53:04 AM2/23/18
to
Greg
Gareth Magennis
Feb 23, 2018, 2:28:41 PM2/23/18
to
"Phil Allison" wrote in message
news:2750eec0-a130-4e4b...@googlegroups.com...
Presumably the transmitter antenna should be straight for best efficiency.
If it is (worst case scenario) a semicircle, what changes?
Gareth.
Phil Allison
Feb 23, 2018, 6:05:07 PM2/23/18
to
Gareth Magennis wrote:
-----------------------
> >
> >
> > Well a piece of wire worked a treat.
> >
> > With a bit of heatshrink for strain relief at the transmitter end and
> > another on the end of the tail, it even looks like a proper one.
> >
> >
>
> ** So now you know how to make a "rat tail" antenna.
>
>
> > Thanks to all for the calculations and info.
>
>
> ** 300 / MHz = wavelength in metres, is worth remembering.
>
>
> FYI:
>
> That AG-1 unit is about as basic as UHF FM links get, so has limited useful
> range and is prone to signal drops out due to multipath interference. The Tx
> signal can almost cancel itself after reflecting off objects and surfaces
> and then arriving at the Rx.
>
> Better models have twin channel receivers, with two separated antennas,
> operating as a diversity pair that helps greatly to eliminate such drop
> outs.
>
>
>
-----------------------
> >
> >
> > Well a piece of wire worked a treat.
> >
> > With a bit of heatshrink for strain relief at the transmitter end and
> > another on the end of the tail, it even looks like a proper one.
> >
> >
>
> ** So now you know how to make a "rat tail" antenna.
>
>
> > Thanks to all for the calculations and info.
>
>
> ** 300 / MHz = wavelength in metres, is worth remembering.
>
>
> FYI:
>
> That AG-1 unit is about as basic as UHF FM links get, so has limited useful
> range and is prone to signal drops out due to multipath interference. The Tx
> signal can almost cancel itself after reflecting off objects and surfaces
> and then arriving at the Rx.
>
> Better models have twin channel receivers, with two separated antennas,
> operating as a diversity pair that helps greatly to eliminate such drop
> outs.
>
>
>
> Presumably the transmitter antenna should be straight for best efficiency.
>
> If it is (worst case scenario) a semicircle, what changes?
>
** Every effort should be made to straighten it !
>
> If it is (worst case scenario) a semicircle, what changes?
>
It's an FM signal, so the recovered audio is not affected until the RF level becomes very weak. Meaning there is usually plenty in reserve to allow for circumstances that reduce the RF level compared to free field.
Players buy units like this not to get long range, but merely to be free of that damn instrument cable.
.... Phil
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