The Murphy Builders Site

Posted: **Sun Feb 19, 2012 4:00 pm**

You're right Ken. I looked at it again, and it listed the Europe output as 5
but the USA was 8. So that is not too bad. I don't know enough about radios
either, to know how much difference that makes. All I know is that I want
more transmit range.

Looks like a nice radio, but would like to see it out for a while too, to
see the price come down. Maybe I can live with my current one a little
longer. It is just that I will have my panel off to do other things related
to the new engine, so this would be a good time.

I like the idea of monitoring two frequencies at the same time. That is very
relevant where I fly here, because of our congested VFR space and different
frequencies in close proximity.

Walter

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Ken
Sent: Thursday, October 11, 2007 5:18 PM
To: rebel-builders@dcsol.com
Subject: [rebel-builders] icomm vhf radio

Walter the brochure that I looked at listed 8 watts of carrier which is
respectable. As I understand it the difference in range between 8 watts
and half that is hardly noticeable but getting the SWR of the antenna
correct is a big factor. The aeroelectric list sometimes asks if you
know any HAM radio operators that might have an SWR meter but I don't
know much about antennas. I would predict that icom will offer $200.
rebates at sun'n fun in addition to competitive pricing. I am not
impressed by the A200 LCD display so I like the A210 display. My A200
is quite sensitive to mic gain adjustments but for all I know all radios
are.
Ken

Walter Klatt wrote:

I checked into this and ended up talking to Tom Glaze at ACS. They needed
500 orders to get that 1058 price, but unfortunately they have only about
100 right now, and likely won't make it to 200 by tomorrow.

While this radio has some nice features, I noticed that it only has 5 watt
transmit output. I thought most had 7 and some have 10.

Some of the places I fly in the mountains here, I am often out of range

with

transmit. I can hear a long ways, but can't talk to them.

Walter

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Posted: **Sun Feb 19, 2012 4:00 pm**

Walter,

The effect of the power is pretty limited where mountains are concerned.
VHF is strictly line of sight with a bit of diffraction around knife
edges in the rocks.

If you can hear them though, it should be possible to put out enough
power that they can hear you. The highest power radio is easy. A better
antenna and antenna placement is also possible.

Most of the antennas on aircraft are 1/4 wavelength monopoles. The
antenna improvemnent potential is about the same as going from 5 watts
to 8 watts. A 5/8 wavelenght antenna similar to vhf mobile antennas
could be made up and if mounted on the roof of the aircraft for best
overall coverage, that would be as good as it gets. The 5/8 wavelength
antenna has a loading coil at the bottom (which would probably be
sub-optimal) if one got an old mobile vhf antenna for about 140 Mhz from
a surplus operator. You could follow Ken's suggestion and using a vswr
meter try to optimize the tuning of the antenna. Length should be close
to 5/8 wavelength, tune the shape and spacing of the loading coil for
low reflected power. Do not touch the antenna while transmitting. RF
burns are not particularly pleasant but 8 watts isn't very hot.

Most people won't use a 5/8 antenna because it is long and tends to lean
back in the wind. A piece of fish line can keep it straight if one
wishes. It is also a bit more drag.

If you want to stay with the 1/4 wavelenght antenna, all you can do is
be sure it has a low reflected power and is put in a good position to
'see' the target antenna.

Garry

Walter Klatt wrote:

You're right Ken. I looked at it again, and it listed the Europe output as 5
but the USA was 8. So that is not too bad. I don't know enough about radios
either, to know how much difference that makes. All I know is that I want
more transmit range.

Looks like a nice radio, but would like to see it out for a while too, to
see the price come down. Maybe I can live with my current one a little
longer. It is just that I will have my panel off to do other things related
to the new engine, so this would be a good time.

I like the idea of monitoring two frequencies at the same time. That is very
relevant where I fly here, because of our congested VFR space and different
frequencies in close proximity.

Walter

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Ken
Sent: Thursday, October 11, 2007 5:18 PM
To: rebel-builders@dcsol.com
Subject: [rebel-builders] icomm vhf radio

Walter the brochure that I looked at listed 8 watts of carrier which is
respectable. As I understand it the difference in range between 8 watts
and half that is hardly noticeable but getting the SWR of the antenna
correct is a big factor. The aeroelectric list sometimes asks if you
know any HAM radio operators that might have an SWR meter but I don't
know much about antennas. I would predict that icom will offer $200.
rebates at sun'n fun in addition to competitive pricing. I am not
impressed by the A200 LCD display so I like the A210 display. My A200
is quite sensitive to mic gain adjustments but for all I know all radios
are.
Ken

Walter Klatt wrote:

I checked into this and ended up talking to Tom Glaze at ACS. They needed
500 orders to get that 1058 price, but unfortunately they have only about
100 right now, and likely won't make it to 200 by tomorrow.

While this radio has some nice features, I noticed that it only has 5 watt
transmit output. I thought most had 7 and some have 10.

Some of the places I fly in the mountains here, I am often out of range
with
transmit. I can hear a long ways, but can't talk to them.

Walter

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Posted: **Sun Feb 19, 2012 4:00 pm**

Huh?
Wow, I understood about 10% of that. Let me ask this. Is there anyway that one
can put together a "HF" radio at a reasonable price?
Eddie Moran

Garry Wright <wrightdg@davincibb.net> wrote:
Walter,

The effect of the power is pretty limited where mountains are concerned.
VHF is strictly line of sight with a bit of diffraction around knife
edges in the rocks.

If you can hear them though, it should be possible to put out enough
power that they can hear you. The highest power radio is easy. A better
antenna and antenna placement is also possible.

Most of the antennas on aircraft are 1/4 wavelength monopoles. The
antenna improvemnent potential is about the same as going from 5 watts
to 8 watts. A 5/8 wavelenght antenna similar to vhf mobile antennas
could be made up and if mounted on the roof of the aircraft for best
overall coverage, that would be as good as it gets. The 5/8 wavelength
antenna has a loading coil at the bottom (which would probably be
sub-optimal) if one got an old mobile vhf antenna for about 140 Mhz from
a surplus operator. You could follow Ken's suggestion and using a vswr
meter try to optimize the tuning of the antenna. Length should be close
to 5/8 wavelength, tune the shape and spacing of the loading coil for
low reflected power. Do not touch the antenna while transmitting. RF
burns are not particularly pleasant but 8 watts isn't very hot.

Most people won't use a 5/8 antenna because it is long and tends to lean
back in the wind. A piece of fish line can keep it straight if one
wishes. It is also a bit more drag.

If you want to stay with the 1/4 wavelenght antenna, all you can do is
be sure it has a low reflected power and is put in a good position to
'see' the target antenna.

Garry

Walter Klatt wrote:

You're right Ken. I looked at it again, and it listed the Europe output as 5
but the USA was 8. So that is not too bad. I don't know enough about radios
either, to know how much difference that makes. All I know is that I want
more transmit range.

Looks like a nice radio, but would like to see it out for a while too, to
see the price come down. Maybe I can live with my current one a little
longer. It is just that I will have my panel off to do other things related
to the new engine, so this would be a good time.

I like the idea of monitoring two frequencies at the same time. That is very
relevant where I fly here, because of our congested VFR space and different
frequencies in close proximity.

Walter

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Ken
Sent: Thursday, October 11, 2007 5:18 PM
To: rebel-builders@dcsol.com
Subject: [rebel-builders] icomm vhf radio

Walter the brochure that I looked at listed 8 watts of carrier which is
respectable. As I understand it the difference in range between 8 watts
and half that is hardly noticeable but getting the SWR of the antenna
correct is a big factor. The aeroelectric list sometimes asks if you
know any HAM radio operators that might have an SWR meter but I don't
know much about antennas. I would predict that icom will offer $200.
rebates at sun'n fun in addition to competitive pricing. I am not
impressed by the A200 LCD display so I like the A210 display. My A200
is quite sensitive to mic gain adjustments but for all I know all radios
are.
Ken

Walter Klatt wrote:

I checked into this and ended up talking to Tom Glaze at ACS. They needed
500 orders to get that 1058 price, but unfortunately they have only about
100 right now, and likely won't make it to 200 by tomorrow.

While this radio has some nice features, I noticed that it only has 5 watt
transmit output. I thought most had 7 and some have 10.

Some of the places I fly in the mountains here, I am often out of range
with
transmit. I can hear a long ways, but can't talk to them.

Walter

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Posted: **Sun Feb 19, 2012 4:00 pm**

Thanks, Garry. You obviously know a lot more about radios that I do. I will
save this post, and maybe visit the local avionics shop here, and talk to
them about what more can be done with my plane and antenna.

First, my old radio is pretty crappy, I am quite sure about that. So if I am
going to replace it, I might as well get the best I can, and then improve
the antenna as well. My current antenna and cable was done by the avionics
shop, so I assume they gave me a good one. It cost me enough, as I recall.

But here is what I notice when I fly out to Harrison. I sometimes pick up
guys on the radio way out in the Gulf Islands, and real clear too. They
obviously have very powerful radios or something. Meanwhile, the planes just
50 miles away in the valley here fade away while on the same frequency.
Occasionally, though, I do pick up someone up there too, that comes through
loud and clear. So I assumed they just have more powerful transmitters.

Walter

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Garry
Wright
Sent: Thursday, October 11, 2007 6:56 PM
To: rebel-builders@dcsol.com
Subject: Re: [rebel-builders] icomm vhf radio

Walter,

The effect of the power is pretty limited where mountains are concerned.
VHF is strictly line of sight with a bit of diffraction around knife
edges in the rocks.

If you can hear them though, it should be possible to put out enough
power that they can hear you. The highest power radio is easy. A better
antenna and antenna placement is also possible.

Most of the antennas on aircraft are 1/4 wavelength monopoles. The
antenna improvemnent potential is about the same as going from 5 watts
to 8 watts. A 5/8 wavelenght antenna similar to vhf mobile antennas
could be made up and if mounted on the roof of the aircraft for best
overall coverage, that would be as good as it gets. The 5/8 wavelength
antenna has a loading coil at the bottom (which would probably be
sub-optimal) if one got an old mobile vhf antenna for about 140 Mhz from
a surplus operator. You could follow Ken's suggestion and using a vswr
meter try to optimize the tuning of the antenna. Length should be close
to 5/8 wavelength, tune the shape and spacing of the loading coil for
low reflected power. Do not touch the antenna while transmitting. RF
burns are not particularly pleasant but 8 watts isn't very hot.

Most people won't use a 5/8 antenna because it is long and tends to lean
back in the wind. A piece of fish line can keep it straight if one
wishes. It is also a bit more drag.

If you want to stay with the 1/4 wavelenght antenna, all you can do is
be sure it has a low reflected power and is put in a good position to
'see' the target antenna.

Garry

Walter Klatt wrote:

You're right Ken. I looked at it again, and it listed the Europe output as

5

but the USA was 8. So that is not too bad. I don't know enough about

radios

either, to know how much difference that makes. All I know is that I want
more transmit range.

Looks like a nice radio, but would like to see it out for a while too, to
see the price come down. Maybe I can live with my current one a little
longer. It is just that I will have my panel off to do other things

to the new engine, so this would be a good time.

I like the idea of monitoring two frequencies at the same time. That is

very

relevant where I fly here, because of our congested VFR space and

different

frequencies in close proximity.

Walter

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Ken
Sent: Thursday, October 11, 2007 5:18 PM
To: rebel-builders@dcsol.com
Subject: [rebel-builders] icomm vhf radio

Walter the brochure that I looked at listed 8 watts of carrier which is
respectable. As I understand it the difference in range between 8 watts
and half that is hardly noticeable but getting the SWR of the antenna
correct is a big factor. The aeroelectric list sometimes asks if you
know any HAM radio operators that might have an SWR meter but I don't
know much about antennas. I would predict that icom will offer $200.
rebates at sun'n fun in addition to competitive pricing. I am not
impressed by the A200 LCD display so I like the A210 display. My A200
is quite sensitive to mic gain adjustments but for all I know all radios
are.
Ken

Walter Klatt wrote:

I checked into this and ended up talking to Tom Glaze at ACS. They needed
500 orders to get that 1058 price, but unfortunately they have only about
100 right now, and likely won't make it to 200 by tomorrow.

While this radio has some nice features, I noticed that it only has 5

watt

transmit output. I thought most had 7 and some have 10.

Some of the places I fly in the mountains here, I am often out of range
with
transmit. I can hear a long ways, but can't talk to them.

Walter

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Posted: **Sun Feb 19, 2012 4:01 pm**

The Garmin SL-40 is advertised at 8 watts with dual frequency monitoring. It
does cost more than the Icom discount that you are discussing, but is a
popular radio for the many LSA planes being produced right now.

The SL-40 used to be the Apollo SL-40 before Garmin bought the company. So,
the radio has been in the field for many years.

Eric

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Walter
Klatt
Sent: Thursday, October 11, 2007 5:37 PM
To: rebel-builders@dcsol.com
Subject: RE: [rebel-builders] icomm vhf radio

You're right Ken. I looked at it again, and it listed the Europe output as 5
but the USA was 8. So that is not too bad. I don't know enough about radios
either, to know how much difference that makes. All I know is that I want
more transmit range.

Looks like a nice radio, but would like to see it out for a while too, to
see the price come down. Maybe I can live with my current one a little
longer. It is just that I will have my panel off to do other things related
to the new engine, so this would be a good time.

I like the idea of monitoring two frequencies at the same time. That is very
relevant where I fly here, because of our congested VFR space and different
frequencies in close proximity.

Walter

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Ken
Sent: Thursday, October 11, 2007 5:18 PM
To: rebel-builders@dcsol.com
Subject: [rebel-builders] icomm vhf radio

Walter the brochure that I looked at listed 8 watts of carrier which is
respectable. As I understand it the difference in range between 8 watts
and half that is hardly noticeable but getting the SWR of the antenna
correct is a big factor. The aeroelectric list sometimes asks if you
know any HAM radio operators that might have an SWR meter but I don't
know much about antennas. I would predict that icom will offer $200.
rebates at sun'n fun in addition to competitive pricing. I am not
impressed by the A200 LCD display so I like the A210 display. My A200
is quite sensitive to mic gain adjustments but for all I know all radios
are.
Ken

Walter Klatt wrote:

I checked into this and ended up talking to Tom Glaze at ACS. They needed
500 orders to get that 1058 price, but unfortunately they have only about
100 right now, and likely won't make it to 200 by tomorrow.

While this radio has some nice features, I noticed that it only has 5 watt
transmit output. I thought most had 7 and some have 10.

Some of the places I fly in the mountains here, I am often out of range

with

transmit. I can hear a long ways, but can't talk to them.

Walter

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Posted: **Sun Feb 19, 2012 4:01 pm**

Only ham radio as far as I know. Aviation stuff for HF on the
tran-oceanic routes is very expensive and not in the ham bands.

Garry

Eddie Moran wrote:

Huh?
Wow, I understood about 10% of that. Let me ask this. Is there anyway that one
can put together a "HF" radio at a reasonable price?
Eddie Moran

Garry Wright <wrightdg@davincibb.net> wrote:
Walter,

The effect of the power is pretty limited where mountains are concerned.
VHF is strictly line of sight with a bit of diffraction around knife
edges in the rocks.

If you can hear them though, it should be possible to put out enough
power that they can hear you. The highest power radio is easy. A better
antenna and antenna placement is also possible.

Most of the antennas on aircraft are 1/4 wavelength monopoles. The
antenna improvemnent potential is about the same as going from 5 watts
to 8 watts. A 5/8 wavelenght antenna similar to vhf mobile antennas
could be made up and if mounted on the roof of the aircraft for best
overall coverage, that would be as good as it gets. The 5/8 wavelength
antenna has a loading coil at the bottom (which would probably be
sub-optimal) if one got an old mobile vhf antenna for about 140 Mhz from
a surplus operator. You could follow Ken's suggestion and using a vswr
meter try to optimize the tuning of the antenna. Length should be close
to 5/8 wavelength, tune the shape and spacing of the loading coil for
low reflected power. Do not touch the antenna while transmitting. RF
burns are not particularly pleasant but 8 watts isn't very hot.

Most people won't use a 5/8 antenna because it is long and tends to lean
back in the wind. A piece of fish line can keep it straight if one
wishes. It is also a bit more drag.

If you want to stay with the 1/4 wavelenght antenna, all you can do is
be sure it has a low reflected power and is put in a good position to
'see' the target antenna.

Garry

Walter Klatt wrote:
You're right Ken. I looked at it again, and it listed the Europe output as 5
but the USA was 8. So that is not too bad. I don't know enough about radios
either, to know how much difference that makes. All I know is that I want
more transmit range.

Looks like a nice radio, but would like to see it out for a while too, to
see the price come down. Maybe I can live with my current one a little
longer. It is just that I will have my panel off to do other things related
to the new engine, so this would be a good time.

I like the idea of monitoring two frequencies at the same time. That is very
relevant where I fly here, because of our congested VFR space and different
frequencies in close proximity.

Walter

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Ken
Sent: Thursday, October 11, 2007 5:18 PM
To: rebel-builders@dcsol.com
Subject: [rebel-builders] icomm vhf radio

Walter the brochure that I looked at listed 8 watts of carrier which is
respectable. As I understand it the difference in range between 8 watts
and half that is hardly noticeable but getting the SWR of the antenna
correct is a big factor. The aeroelectric list sometimes asks if you
know any HAM radio operators that might have an SWR meter but I don't
know much about antennas. I would predict that icom will offer $200.
rebates at sun'n fun in addition to competitive pricing. I am not
impressed by the A200 LCD display so I like the A210 display. My A200
is quite sensitive to mic gain adjustments but for all I know all radios
are.
Ken

Walter Klatt wrote:

I checked into this and ended up talking to Tom Glaze at ACS. They needed
500 orders to get that 1058 price, but unfortunately they have only about
100 right now, and likely won't make it to 200 by tomorrow.

While this radio has some nice features, I noticed that it only has 5 watt
transmit output. I thought most had 7 and some have 10.

Some of the places I fly in the mountains here, I am often out of range
with
transmit. I can hear a long ways, but can't talk to them.

Walter

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Posted: **Sun Feb 19, 2012 4:01 pm**

You could be experiencing very poor radiation patterns in the vertical
plane from your antenna. They are not meant to radiate downward much.
Ideally the aviation antenna is to put as much radiation into the
horizontal directions as possible while limiting the 'wasted' radiation
up into space or down to the dirt. Actually, if you have a clear line of
sight as you must to the gulf islands, the amount of power needed is
very small. A milliwatt would likely do it. Just another image of how
little power matters and path dominates.

Garry

Walter Klatt wrote:

Thanks, Garry. You obviously know a lot more about radios that I do. I will
save this post, and maybe visit the local avionics shop here, and talk to
them about what more can be done with my plane and antenna.

First, my old radio is pretty crappy, I am quite sure about that. So if I am
going to replace it, I might as well get the best I can, and then improve
the antenna as well. My current antenna and cable was done by the avionics
shop, so I assume they gave me a good one. It cost me enough, as I recall.

But here is what I notice when I fly out to Harrison. I sometimes pick up
guys on the radio way out in the Gulf Islands, and real clear too. They
obviously have very powerful radios or something. Meanwhile, the planes just
50 miles away in the valley here fade away while on the same frequency.
Occasionally, though, I do pick up someone up there too, that comes through
loud and clear. So I assumed they just have more powerful transmitters.

Walter

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Garry
Wright
Sent: Thursday, October 11, 2007 6:56 PM
To: rebel-builders@dcsol.com
Subject: Re: [rebel-builders] icomm vhf radio

Walter,

The effect of the power is pretty limited where mountains are concerned.
VHF is strictly line of sight with a bit of diffraction around knife
edges in the rocks.

If you can hear them though, it should be possible to put out enough
power that they can hear you. The highest power radio is easy. A better
antenna and antenna placement is also possible.

Most of the antennas on aircraft are 1/4 wavelength monopoles. The
antenna improvemnent potential is about the same as going from 5 watts
to 8 watts. A 5/8 wavelenght antenna similar to vhf mobile antennas
could be made up and if mounted on the roof of the aircraft for best
overall coverage, that would be as good as it gets. The 5/8 wavelength
antenna has a loading coil at the bottom (which would probably be
sub-optimal) if one got an old mobile vhf antenna for about 140 Mhz from
a surplus operator. You could follow Ken's suggestion and using a vswr
meter try to optimize the tuning of the antenna. Length should be close
to 5/8 wavelength, tune the shape and spacing of the loading coil for
low reflected power. Do not touch the antenna while transmitting. RF
burns are not particularly pleasant but 8 watts isn't very hot.

Most people won't use a 5/8 antenna because it is long and tends to lean
back in the wind. A piece of fish line can keep it straight if one
wishes. It is also a bit more drag.

If you want to stay with the 1/4 wavelenght antenna, all you can do is
be sure it has a low reflected power and is put in a good position to
'see' the target antenna.

Garry

Walter Klatt wrote:
You're right Ken. I looked at it again, and it listed the Europe output as
5
but the USA was 8. So that is not too bad. I don't know enough about
radios
either, to know how much difference that makes. All I know is that I want
more transmit range.

Looks like a nice radio, but would like to see it out for a while too, to
see the price come down. Maybe I can live with my current one a little
longer. It is just that I will have my panel off to do other things
related
to the new engine, so this would be a good time.

I like the idea of monitoring two frequencies at the same time. That is
very
relevant where I fly here, because of our congested VFR space and
different
frequencies in close proximity.

Walter

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Ken
Sent: Thursday, October 11, 2007 5:18 PM
To: rebel-builders@dcsol.com
Subject: [rebel-builders] icomm vhf radio

Walter the brochure that I looked at listed 8 watts of carrier which is
respectable. As I understand it the difference in range between 8 watts
and half that is hardly noticeable but getting the SWR of the antenna
correct is a big factor. The aeroelectric list sometimes asks if you
know any HAM radio operators that might have an SWR meter but I don't
know much about antennas. I would predict that icom will offer $200.
rebates at sun'n fun in addition to competitive pricing. I am not
impressed by the A200 LCD display so I like the A210 display. My A200
is quite sensitive to mic gain adjustments but for all I know all radios
are.
Ken

Walter Klatt wrote:

I checked into this and ended up talking to Tom Glaze at ACS. They needed
500 orders to get that 1058 price, but unfortunately they have only about
100 right now, and likely won't make it to 200 by tomorrow.

While this radio has some nice features, I noticed that it only has 5
watt
transmit output. I thought most had 7 and some have 10.

Some of the places I fly in the mountains here, I am often out of range
with
transmit. I can hear a long ways, but can't talk to them.

Walter

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Posted: **Sun Feb 19, 2012 4:01 pm**

Hi Walter
If you get a more powerful transmitter and need to find a ham operator in
your area to borrow a SWR or antenna analyser let me know and I'll try to
track one down for you.
Nig
745E
M0BUH

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com]On Behalf Of
Walter Klatt
Sent: 12 October 2007 01:37
To: rebel-builders@dcsol.com
Subject: RE: [rebel-builders] icomm vhf radio

You're right Ken. I looked at it again, and it listed the Europe output as 5
but the USA was 8. So that is not too bad. I don't know enough about radios
either, to know how much difference that makes. All I know is that I want
more transmit range.

Looks like a nice radio, but would like to see it out for a while too, to
see the price come down. Maybe I can live with my current one a little
longer. It is just that I will have my panel off to do other things related
to the new engine, so this would be a good time.

I like the idea of monitoring two frequencies at the same time. That is very
relevant where I fly here, because of our congested VFR space and different
frequencies in close proximity.

Walter

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Ken
Sent: Thursday, October 11, 2007 5:18 PM
To: rebel-builders@dcsol.com
Subject: [rebel-builders] icomm vhf radio

Walter the brochure that I looked at listed 8 watts of carrier which is
respectable. As I understand it the difference in range between 8 watts
and half that is hardly noticeable but getting the SWR of the antenna
correct is a big factor. The aeroelectric list sometimes asks if you
know any HAM radio operators that might have an SWR meter but I don't
know much about antennas. I would predict that icom will offer $200.
rebates at sun'n fun in addition to competitive pricing. I am not
impressed by the A200 LCD display so I like the A210 display. My A200
is quite sensitive to mic gain adjustments but for all I know all radios
are.
Ken

Walter Klatt wrote:

I checked into this and ended up talking to Tom Glaze at ACS. They needed
500 orders to get that 1058 price, but unfortunately they have only about
100 right now, and likely won't make it to 200 by tomorrow.

While this radio has some nice features, I noticed that it only has 5 watt
transmit output. I thought most had 7 and some have 10.

Some of the places I fly in the mountains here, I am often out of range

with

transmit. I can hear a long ways, but can't talk to them.

Walter

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Posted: **Sun Feb 19, 2012 4:01 pm**

A way to test for radiation pattern is to establish comm with someone
(maybe with a handheld?) then turn the aircraft say 30 degrees, level
the wings and test again. Keep doing that until you've gone all the way
around the compass. All aircraft will have noticeable differences on
different headings but some will have really bad spots that can only be
fixed by relocating the antenna AFAIK. Someone who knows more can
comment, but I believe reception my be good on some headings but
transmissions poor.

Antennas should be located such that there is metal aircraft skin (the
ground plane) surrounding them in all directions for a radius about the
same as the antenna length to minimise dead spots. I would guess that a
vertical antenna also might be a bit better than the popular sloping
rearward antenna. Even putting flap down and lowering the nose to make
the top of the wing more horizontal might help. I'm also told that poor
grounding of the coax to the metal aircraft skin at the antenna is
common, especially on older installations. I think it is also a good
idea to avoid really tight bends in the coax, especially if using old
coax such as teflon insulated stuff where the core tends to extrude off
center after awhile.

I know what you mean about reception. This summer we estimated that
Garry was weak and unintelligible after perhaps 30 miles when he pulled
ahead even on the prairies. There was never any trouble understanding
Bob when he got distant. Unfortunately I routinely hear guys calling in
the circuit over a 100 miles away and would be happy if my reception was
poorer...

Ken

Garry Wright wrote:

You could be experiencing very poor radiation patterns in the vertical
plane from your antenna. They are not meant to radiate downward much.
Ideally the aviation antenna is to put as much radiation into the
horizontal directions as possible while limiting the 'wasted' radiation
up into space or down to the dirt. Actually, if you have a clear line of
sight as you must to the gulf islands, the amount of power needed is
very small. A milliwatt would likely do it. Just another image of how
little power matters and path dominates.

Garry

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Posted: **Sun Feb 19, 2012 4:01 pm**

The test below would be difficult without some sort of signal strength
meter and a set of attenuators to get the signal down to where you could
notice a change of a few dB. Ken's comments on the ground plane are
right on. I will take a look at mine and see what I have. Not sure what
my antenna is actually. The plumber's toilets never work very well do they?

Garry

Ken wrote:

A way to test for radiation pattern is to establish comm with someone
(maybe with a handheld?) then turn the aircraft say 30 degrees, level
the wings and test again. Keep doing that until you've gone all the way
around the compass. All aircraft will have noticeable differences on
different headings but some will have really bad spots that can only be
fixed by relocating the antenna AFAIK. Someone who knows more can
comment, but I believe reception my be good on some headings but
transmissions poor.

Antennas should be located such that there is metal aircraft skin (the
ground plane) surrounding them in all directions for a radius about the
same as the antenna length to minimise dead spots. I would guess that a
vertical antenna also might be a bit better than the popular sloping
rearward antenna. Even putting flap down and lowering the nose to make
the top of the wing more horizontal might help. I'm also told that poor
grounding of the coax to the metal aircraft skin at the antenna is
common, especially on older installations. I think it is also a good
idea to avoid really tight bends in the coax, especially if using old
coax such as teflon insulated stuff where the core tends to extrude off
center after awhile.

I know what you mean about reception. This summer we estimated that
Garry was weak and unintelligible after perhaps 30 miles when he pulled
ahead even on the prairies. There was never any trouble understanding
Bob when he got distant. Unfortunately I routinely hear guys calling in
the circuit over a 100 miles away and would be happy if my reception was
poorer...

Ken

Garry Wright wrote:

You could be experiencing very poor radiation patterns in the vertical
plane from your antenna. They are not meant to radiate downward much.
Ideally the aviation antenna is to put as much radiation into the
horizontal directions as possible while limiting the 'wasted' radiation
up into space or down to the dirt. Actually, if you have a clear line of
sight as you must to the gulf islands, the amount of power needed is
very small. A milliwatt would likely do it. Just another image of how
little power matters and path dominates.

Garry

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Posted: **Sun Feb 19, 2012 4:01 pm**

I actually have one of those SWR analyzers and did some testing of my radio
and antenna a couple years back. It seams that on the ground it works fine,
but I get noise in the air. It is inconsistent, too, and have tried all
kinds of different noise filters. I even played with my mic gain adjustment,
as that seemed to have an effect as well. I think what happens sometimes, is
that the radio automatically reduces transmit power under certain conditions
of noise, I think. I remember going through the manuals one time and reading
something about that. Shutting it off and back on in flight sometimes works,
too.

In any case, the radio has to go, and if I still have noise or antenna
problems, will have to address that as well.

Walter

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of
N.Smith
Sent: Thursday, October 11, 2007 11:04 PM
To: rebel-builders@dcsol.com
Subject: RE: [rebel-builders] icomm vhf radio

Hi Walter
If you get a more powerful transmitter and need to find a ham operator in
your area to borrow a SWR or antenna analyser let me know and I'll try to
track one down for you.
Nig
745E
M0BUH

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com]On Behalf Of
Walter Klatt
Sent: 12 October 2007 01:37
To: rebel-builders@dcsol.com
Subject: RE: [rebel-builders] icomm vhf radio

You're right Ken. I looked at it again, and it listed the Europe output as 5
but the USA was 8. So that is not too bad. I don't know enough about radios
either, to know how much difference that makes. All I know is that I want
more transmit range.

Looks like a nice radio, but would like to see it out for a while too, to
see the price come down. Maybe I can live with my current one a little
longer. It is just that I will have my panel off to do other things related
to the new engine, so this would be a good time.

I like the idea of monitoring two frequencies at the same time. That is very
relevant where I fly here, because of our congested VFR space and different
frequencies in close proximity.

Walter

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Ken
Sent: Thursday, October 11, 2007 5:18 PM
To: rebel-builders@dcsol.com
Subject: [rebel-builders] icomm vhf radio

Walter the brochure that I looked at listed 8 watts of carrier which is
respectable. As I understand it the difference in range between 8 watts
and half that is hardly noticeable but getting the SWR of the antenna
correct is a big factor. The aeroelectric list sometimes asks if you
know any HAM radio operators that might have an SWR meter but I don't
know much about antennas. I would predict that icom will offer $200.
rebates at sun'n fun in addition to competitive pricing. I am not
impressed by the A200 LCD display so I like the A210 display. My A200
is quite sensitive to mic gain adjustments but for all I know all radios
are.
Ken

Walter Klatt wrote:

I checked into this and ended up talking to Tom Glaze at ACS. They needed
500 orders to get that 1058 price, but unfortunately they have only about
100 right now, and likely won't make it to 200 by tomorrow.

While this radio has some nice features, I noticed that it only has 5 watt
transmit output. I thought most had 7 and some have 10.

Some of the places I fly in the mountains here, I am often out of range

with

transmit. I can hear a long ways, but can't talk to them.

Walter

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Posted: **Sun Feb 19, 2012 4:01 pm**

A test at say 30 miles or more and signal strength/dropout will be
obvious won't it??
Ken

Garry Wright wrote:

The test below would be difficult without some sort of signal strength
meter and a set of attenuators to get the signal down to where you could
notice a change of a few dB. Ken's comments on the ground plane are
right on. I will take a look at mine and see what I have. Not sure what
my antenna is actually. The plumber's toilets never work very well do they?

Garry

Ken wrote:

A way to test for radiation pattern is to establish comm with someone
(maybe with a handheld?) then turn the aircraft say 30 degrees, level
the wings and test again. Keep doing that until you've gone all the way
around the compass. All aircraft will have noticeable differences on
different headings but some will have really bad spots that can only be
fixed by relocating the antenna AFAIK. Someone who knows more can
comment, but I believe reception my be good on some headings but
transmissions poor.

Antennas should be located such that there is metal aircraft skin (the
ground plane) surrounding them in all directions for a radius about the
same as the antenna length to minimise dead spots. I would guess that a
vertical antenna also might be a bit better than the popular sloping
rearward antenna. Even putting flap down and lowering the nose to make
the top of the wing more horizontal might help. I'm also told that poor
grounding of the coax to the metal aircraft skin at the antenna is
common, especially on older installations. I think it is also a good
idea to avoid really tight bends in the coax, especially if using old
coax such as teflon insulated stuff where the core tends to extrude off
center after awhile.

I know what you mean about reception. This summer we estimated that
Garry was weak and unintelligible after perhaps 30 miles when he pulled
ahead even on the prairies. There was never any trouble understanding
Bob when he got distant. Unfortunately I routinely hear guys calling in
the circuit over a 100 miles away and would be happy if my reception was
poorer...

Ken

Garry Wright wrote:

You could be experiencing very poor radiation patterns in the vertical
plane from your antenna. They are not meant to radiate downward much.
Ideally the aviation antenna is to put as much radiation into the
horizontal directions as possible while limiting the 'wasted' radiation
up into space or down to the dirt. Actually, if you have a clear line of
sight as you must to the gulf islands, the amount of power needed is
very small. A milliwatt would likely do it. Just another image of how
little power matters and path dominates.

Garry

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Posted: **Sun Feb 19, 2012 4:01 pm**

yep.

Ken wrote:

A test at say 30 miles or more and signal strength/dropout will be
obvious won't it??
Ken

Garry Wright wrote:

The test below would be difficult without some sort of signal strength
meter and a set of attenuators to get the signal down to where you could
notice a change of a few dB. Ken's comments on the ground plane are
right on. I will take a look at mine and see what I have. Not sure what
my antenna is actually. The plumber's toilets never work very well do they?

Garry

Ken wrote:

A way to test for radiation pattern is to establish comm with someone
(maybe with a handheld?) then turn the aircraft say 30 degrees, level
the wings and test again. Keep doing that until you've gone all the way
around the compass. All aircraft will have noticeable differences on
different headings but some will have really bad spots that can only be
fixed by relocating the antenna AFAIK. Someone who knows more can
comment, but I believe reception my be good on some headings but
transmissions poor.

Antennas should be located such that there is metal aircraft skin (the
ground plane) surrounding them in all directions for a radius about the
same as the antenna length to minimise dead spots. I would guess that a
vertical antenna also might be a bit better than the popular sloping
rearward antenna. Even putting flap down and lowering the nose to make
the top of the wing more horizontal might help. I'm also told that poor
grounding of the coax to the metal aircraft skin at the antenna is
common, especially on older installations. I think it is also a good
idea to avoid really tight bends in the coax, especially if using old
coax such as teflon insulated stuff where the core tends to extrude off
center after awhile.

I know what you mean about reception. This summer we estimated that
Garry was weak and unintelligible after perhaps 30 miles when he pulled
ahead even on the prairies. There was never any trouble understanding
Bob when he got distant. Unfortunately I routinely hear guys calling in
the circuit over a 100 miles away and would be happy if my reception was
poorer...

Ken

Garry Wright wrote:

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