FAA Plans to Change to Radios with 8.33 MHz spacing?

[Paul Remde]

Hi,

I imagine someone on this newsgroup can point me in the right direction on a
technical/FAA question.

Becker offers 2 versions of their AR6201 radio. The original version has
frequency spacing that can be set to either 25 mHz or 8.33 mHz. The new,
slightly lower cost option has frequency spacing fixed at 25 MHz It is my
understanding that the 8.33 MHz spacing is required in Europe, but not
currently in the USA. Customers are asking me whether the FAA has any plans
to go to the 8.33 MHz spacing in the near future - so they can be better
equipped to select the radio version that makes sense. At a recent soaring
seminar someone stated that they thought the FAA was going to require radios
with the 8.33 MHz spacing starting in 2020.

Can anyone help me?

Thank you in advance.

Paul Remde
Cumulus Soaring, Inc.

[Richard[_9_]]

On Thursday, April 11, 2013 2:33:51 PM UTC-7, Paul Remde wrote:
> Hi, I imagine someone on this newsgroup can point me in the right direction on a technical/FAA question. Becker offers 2 versions of their AR6201 radio. The original version has frequency spacing that can be set to either 25 mHz or 8.33 mHz. The new, slightly lower cost option has frequency spacing fixed at 25 MHz It is my understanding that the 8.33 MHz spacing is required in Europe, but not currently in the USA. Customers are asking me whether the FAA has any plans to go to the 8.33 MHz spacing in the near future - so they can be better equipped to select the radio version that makes sense.. At a recent soaring seminar someone stated that they thought the FAA was going to require radios with the 8.33 MHz spacing starting in 2020. Can anyone help me? Thank you in advance. Paul Remde Cumulus Soaring, Inc.

Google can help.

Richard
www.craggyaero.com

[Wayne Paul]

Paul,

Am I missing something here? Don't we currently have 0.25 MHz spacing and
isn't the plan to divide that into three channels which would make 0.0833
MHz spacing?

Respectfully,

Wayne



"Paul Remde" wrote in message ...

Hi,

I imagine someone on this newsgroup can point me in the right direction on a
technical/FAA question.

Becker offers 2 versions of their AR6201 radio. The original version has
frequency spacing that can be set to either 25 mHz or 8.33 mHz. The new,
slightly lower cost option has frequency spacing fixed at 25 MHz It is my
understanding that the 8.33 MHz spacing is required in Europe, but not
currently in the USA. Customers are asking me whether the FAA has any plans
to go to the 8.33 MHz spacing in the near future - so they can be better
equipped to select the radio version that makes sense. At a recent soaring
seminar someone stated that they thought the FAA was going to require radios
with the 8.33 MHz spacing starting in 2020.

Can anyone help me?

Thank you in advance.

Paul Remde
Cumulus Soaring, Inc.

[Andrzej Kobus]

On Apr 11, 5:33*pm, "Paul Remde" > wrote:
> Hi,
>
> I imagine someone on this newsgroup can point me in the right direction on a
> technical/FAA question.
>
> Becker offers 2 versions of their AR6201 radio. *The original version has
> frequency spacing that can be set to either 25 mHz or 8.33 mHz. *The new,
> slightly lower cost option has frequency spacing fixed at 25 MHz *It is my
> understanding that the 8.33 MHz spacing is required in Europe, but not
> currently in the USA. *Customers are asking me whether the FAA has any plans
> to go to the 8.33 MHz spacing in the near future - so they can be better
> equipped to select the radio version that makes sense. *At a recent soaring
> seminar someone stated that they thought the FAA was going to require radios
> with the 8.33 MHz spacing starting in 2020.
>
> Can anyone help me?
>
> Thank you in advance.
>
> Paul Remde
> Cumulus Soaring, Inc.

I don't think that would fly. This is not Europe (luckily) where they
have mandate to swap ALL radios by 2018. I could see a requirement
being introduced for such channel spacing in busiest airspace some
time into the future or above certain FL. In Europe the requirement
was introduced in 1994 and it only required 8.33 spacing for above
FL245 then with time it was pushed down to be generally mandated by
2018.

[Andy[_1_]]

On Thursday, April 11, 2013 4:11:12 PM UTC-7, Wayne wrote:
> Paul, Am I missing something here? Don't we currently have 0.25 MHz spacing and isn't the plan to divide that into three channels which would make 0.0833 MHz spacing? Respectfully, Wayne


Only thing missing is the correct placement of the decimal point ;)

25kHz, 8.33kHz

Andy

[Bob Kuykendall]

On Apr 11, 2:33*pm, "Paul Remde" > wrote:
>... *At a recent soaring
> seminar someone stated that they thought the FAA was
> going to require radios with the 8.33 MHz spacing starting in 2020.

I will be someewhat surprised if we get to 2020 and we are still using
what we think of today as "aircraft radios." I think that by then we
will find that the bandwidth dedicated to those old grampa boxes will
have been divided up and auctioned off, and we will be communicating
over a system based on mobile phone infrastructure.

If I'm wrong, I'll buy you a beer at the 2020 SSA convention. Offer
limited to the first 24 "I told ya sos."

Thanks, Bob K.

[Eric Greenwell[_4_]]

On 4/11/2013 7:12 PM, Bob Kuykendall wrote:
> On Apr 11, 2:33 pm, "Paul Remde" > wrote:
>> ... At a recent soaring
>> seminar someone stated that they thought the FAA was
>> going to require radios with the 8.33 MHz spacing starting in 2020.
>
> I will be someewhat surprised if we get to 2020 and we are still using
> what we think of today as "aircraft radios." I think that by then we
> will find that the bandwidth dedicated to those old grampa boxes will
> have been divided up and auctioned off, and we will be communicating
> over a system based on mobile phone infrastructure.
>
> If I'm wrong, I'll buy you a beer at the 2020 SSA convention. Offer
> limited to the first 24 "I told ya sos."

Is there still a premium for the extra channels? The last panel mount
radio I bought had 8.33 khz spacing (you can disable it for easier
tuning). It was only $23 more than their 25 kHz spacing unit.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[Eric Greenwell[_4_]]

On 4/11/2013 7:12 PM, Bob Kuykendall wrote:
> On Apr 11, 2:33 pm, "Paul Remde" > wrote:
>> ... At a recent soaring
>> seminar someone stated that they thought the FAA was
>> going to require radios with the 8.33 MHz spacing starting in 2020.
>
> I will be someewhat surprised if we get to 2020 and we are still using
> what we think of today as "aircraft radios." I think that by then we
> will find that the bandwidth dedicated to those old grampa boxes will
> have been divided up and auctioned off, and we will be communicating
> over a system based on mobile phone infrastructure.
>
> If I'm wrong, I'll buy you a beer at the 2020 SSA convention. Offer
> limited to the first 24 "I told ya sos."

Maybe over the ADS-B system? or something like the FRS "walkie-talkies"?
Dump the AWOS transmissions because we'll get all our weather over
ADS-B? Hey, my next glider can already be ordered with it!

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl

[Bill D]

On Thursday, April 11, 2013 8:12:58 PM UTC-6, Bob Kuykendall wrote:
> On Apr 11, 2:33*pm, "Paul Remde" > wrote:
>
> >... *At a recent soaring
>
> > seminar someone stated that they thought the FAA was
>
> > going to require radios with the 8.33 MHz spacing starting in 2020.
>
>
>
> I will be someewhat surprised if we get to 2020 and we are still using
>
> what we think of today as "aircraft radios." I think that by then we
>
> will find that the bandwidth dedicated to those old grampa boxes will
>
> have been divided up and auctioned off, and we will be communicating
>
> over a system based on mobile phone infrastructure.
>
>
>
> If I'm wrong, I'll buy you a beer at the 2020 SSA convention. Offer
>
> limited to the first 24 "I told ya sos."
>
>
>
> Thanks, Bob K.

I've got a feeling you'll win that bet. By 2020, the 2 meter AM simplex air-band will be nearly 100 years old and very likely the last of its kind in use. It's way past its use-by date. There are better ways to communicate..

[Frank Whiteley]

On Thursday, April 11, 2013 3:33:51 PM UTC-6, Paul Remde wrote:
> Hi,
>
>
>
> I imagine someone on this newsgroup can point me in the right direction on a
>
> technical/FAA question.
>
>
>
> Becker offers 2 versions of their AR6201 radio. The original version has
>
> frequency spacing that can be set to either 25 mHz or 8.33 mHz. The new,
>
> slightly lower cost option has frequency spacing fixed at 25 MHz It is my
>
> understanding that the 8.33 MHz spacing is required in Europe, but not
>
> currently in the USA. Customers are asking me whether the FAA has any plans
>
> to go to the 8.33 MHz spacing in the near future - so they can be better
>
> equipped to select the radio version that makes sense. At a recent soaring
>
> seminar someone stated that they thought the FAA was going to require radios
>
> with the 8.33 MHz spacing starting in 2020.
>
>
>
> Can anyone help me?
>
>
>
> Thank you in advance.
>
>
>
> Paul Remde
>
> Cumulus Soaring, Inc.

http://hraunfoss.fcc.gov/edocs_public/attachmatch/DA-11-1403A1.pdf

http://www.uspa.org/Portals/0/Downloads/FCC-10-103A1.pdf

Don't know about the FAA, but the FCC permits some use under Part 87. Haven't found a mandate, yet.

Frank Whiteley

[[email protected]]

And what sailplane would that be Eric?


> Dump the AWOS transmissions because we'll get all our weather over
>
> ADS-B? Hey, my next glider can already be ordered with it!
>
>Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
>
> email me)

[Eric Greenwell[_4_]]

On 4/12/2013 7:01 AM, wrote:
> And what sailplane would that be Eric?
>
>
>> Dump the AWOS transmissions because we'll get all our weather over
>>
>> ADS-B? Hey, my next glider can already be ordered with it!
>>
>> Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
>>
>> email me)

Phoenix U15 - http://phoenixairusa.com/

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

- "A Guide to Self-launching Sailplane Operation Mar/2004" Much of what
you need to know tinyurl.com/yfs7tnz

[kirk.stant]

On Friday, April 12, 2013 5:06:53 AM UTC+2, Bill D wrote:
> On Thursday, April 11, 2013 8:12:58 PM UTC-6, Bob Kuykendall wrote:
>
> > On Apr 11, 2:33*pm, "Paul Remde" > wrote:
>
> >
>
> > >... *At a recent soaring
>
> >
>
> > > seminar someone stated that they thought the FAA was
>
> >
>
> > > going to require radios with the 8.33 MHz spacing starting in 2020.
>
> >
>
> >
>
> >
>
> > I will be someewhat surprised if we get to 2020 and we are still using
>
> >
>
> > what we think of today as "aircraft radios." I think that by then we
>
> >
>
> > will find that the bandwidth dedicated to those old grampa boxes will
>
> >
>
> > have been divided up and auctioned off, and we will be communicating
>
> >
>
> > over a system based on mobile phone infrastructure.
>
> >
>
> >
>
> >
>
> > If I'm wrong, I'll buy you a beer at the 2020 SSA convention. Offer
>
> >
>
> > limited to the first 24 "I told ya sos."
>
> >
>
> >
>
> >
>
> > Thanks, Bob K.
>
>
>
> I've got a feeling you'll win that bet. By 2020, the 2 meter AM simplex air-band will be nearly 100 years old and very likely the last of its kind in use. It's way past its use-by date. There are better ways to communicate.

I got a feeling you guys will LOSE that bet. The installed base is too big, worldwide, and entrenched to change that quickly - so unless you want to limit yourself to a flarm-like comm system that only works with other similarly-equipped aircraft, and never plan to talk to ATC or other aircraft, you will be stuck with an antique VHF-AM radio.

Plus, good luck with a ground-based cellular comm system over the mid-Atlantic, or the Kalahari desert!

Not to say that a specialized, glider-only comm system couldn't be developed (again, along the FLARM model), but now bandwidth again becomes a problem..

Kirk
66

[Pat Russell[_2_]]

On Apr 11, 5:33*pm, "Paul Remde" > wrote:
> Hi,
>
> I imagine someone on this newsgroup can point me in the right direction on a
> technical/FAA question.
>
> [well-formed question here]
>
> Can anyone help me?

Apparently not, Paul. But it's always fun to watch the responses
wander off in bizarre directions, don't you think?

Good luck.

-Pat

[Alan[_6_]]

In article > Bob Kuykendall > writes:
>On Apr 11, 2:33=A0pm, "Paul Remde" > wrote:
>>... =A0At a recent soaring
>> seminar someone stated that they thought the FAA was
>> going to require radios with the 8.33 MHz spacing starting in 2020.

If they said that, they were confused. Especially since 123.3 and
123.5 are only 0.2 MHz apart. It's 8.33 kHz.

I see it as taking quite a while before it would become mandatory.
How long did it take to make the tighter frequency tolerances mandatory
when 720 channel radios became the norm? Quite a few years, as I recall.


>I will be someewhat surprised if we get to 2020 and we are still using
>what we think of today as "aircraft radios." I think that by then we
>will find that the bandwidth dedicated to those old grampa boxes will
>have been divided up and auctioned off, and we will be communicating
>over a system based on mobile phone infrastructure.

This I don't believe. First off, auctioning off the bandwidth would
not work, since aviation is international, and includes those airliners
that come from other countries that are not into auctioning off spectrum.
A major change would involve international agreements and take some time.

Second, a mobile phone infrastructure system would be using ground
based cell towers (which are not reachable in much of the world, and
not even at an airstrip where I have flown). Also, cellular systems
work by frequency reuse, which requires the limited range of the cell
sites to the mobile phones to make reuse possible within a reasonable
distance. When you are at 10,000 feet, the horizon is about 120 miles
away, so those radio signals will go a long ways, and frequency reuse
becomes more difficult.

Third, there are folks who will reasonably not want their aircraft
communications to be dependent on ground based resources. Presently
even with no functioning ground resources for hundreds of miles, an
aircraft radio on the ground can communicate with one in the air.

Alan

[[email protected]]

I'm already starting to see a trade in used radios from Europe finding their way to North America. You might want to get a European source and start importing quality radios that are being swapped out now.

[Dan Marotta]

It really amuses me how so many people talk about "antique" comm systems.

Why would you need to switch to whoop-de-doo G4, digital, frequency hopping,
DEQPSK (old stuff), wahoo, smart-i-phone thingies, when a VHF-AM 5 watt
transceiver will carry your voice over a hundred miles?

Yeah... I know - you just gotta have real-time satellite photos of the
clouds down to 3.141592 meter resolution so you can keep your $300K glider
in the air for more than 30 minutes.

I'll stick with my antiques, thank you.

And, yes, I understand spectrum congestion.

And, for those who don't get it, I'm yanking your chains. ;-p


> wrote in message
...
> I'm already starting to see a trade in used radios from Europe finding
> their way to North America. You might want to get a European source and
> start importing quality radios that are being swapped out now.

[Bear]

Bob,

I don't believe that we switch to GSM or whatever.

1. For none of the digital communication techniques it was possible to
find a global frequency range.

2. The relative speed is too high. To my knowledge the highest speed to
which a digital communication system is certified is 500 km/h (310 mph).
This is GSM-R, Global System for Mobile Communications - Railway or
GSM-Railway, for details see Wikipedia.
500km/h would be good enough for us but not for others. We can forget it
in aviation thanks to Doppler effect.

Bear


On 12.04.2013 04:12, Bob Kuykendall wrote:
> On Apr 11, 2:33 pm, "Paul Remde" > wrote:
>> ... At a recent soaring
>> seminar someone stated that they thought the FAA was
>> going to require radios with the 8.33 MHz spacing starting in 2020.
>
> I will be someewhat surprised if we get to 2020 and we are still using
> what we think of today as "aircraft radios." I think that by then we
> will find that the bandwidth dedicated to those old grampa boxes will
> have been divided up and auctioned off, and we will be communicating
> over a system based on mobile phone infrastructure.
>
> If I'm wrong, I'll buy you a beer at the 2020 SSA convention. Offer
> limited to the first 24 "I told ya sos."
>
> Thanks, Bob K.
>

[Bill D]

On Saturday, April 13, 2013 12:26:36 PM UTC-6, Bear wrote:
> Bob,
>
>
>
> I don't believe that we switch to GSM or whatever.
>
>
>
> 1. For none of the digital communication techniques it was possible to
>
> find a global frequency range.
>
>
>
> 2. The relative speed is too high. To my knowledge the highest speed to
>
> which a digital communication system is certified is 500 km/h (310 mph).
>
> This is GSM-R, Global System for Mobile Communications - Railway or
>
> GSM-Railway, for details see Wikipedia.
>
> 500km/h would be good enough for us but not for others. We can forget it
>
> in aviation thanks to Doppler effect.
>
>
>
> Bear

So, how is digital communication with 17,000 mph satellites possible with Doppler effects?

Nobody suggested GSM as an alternative to a global aviation-specific digital communications protocol.

[Bear]

What is your proposal?

>
> So, how is digital communication with 17,000 mph satellites possible with Doppler effects?
>
> Nobody suggested GSM as an alternative to a global aviation-specific digital communications protocol.
>

[Dan Marotta]

The satellite ain't goin' 17,000 mph with respect to the ground station.
Doppler will be small with short transmissions.


"Bill D" > wrote in message
...
> On Saturday, April 13, 2013 12:26:36 PM UTC-6, Bear wrote:
>> Bob,
>>
>>
>>
>> I don't believe that we switch to GSM or whatever.
>>
>>
>>
>> 1. For none of the digital communication techniques it was possible to
>>
>> find a global frequency range.
>>
>>
>>
>> 2. The relative speed is too high. To my knowledge the highest speed to
>>
>> which a digital communication system is certified is 500 km/h (310 mph).
>>
>> This is GSM-R, Global System for Mobile Communications - Railway or
>>
>> GSM-Railway, for details see Wikipedia.
>>
>> 500km/h would be good enough for us but not for others. We can forget it
>>
>> in aviation thanks to Doppler effect.
>>
>>
>>
>> Bear
>
> So, how is digital communication with 17,000 mph satellites possible with
> Doppler effects?
>
> Nobody suggested GSM as an alternative to a global aviation-specific
> digital communications protocol.

[Alan[_6_]]

In article > Bear > writes:
>Bob,
>
>I don't believe that we switch to GSM or whatever.
>
>1. For none of the digital communication techniques it was possible to
>find a global frequency range.

Seems unlikely. Are you saying that there is no VHF or UHF band available
worldwide?


>2. The relative speed is too high. To my knowledge the highest speed to
>which a digital communication system is certified is 500 km/h (310 mph).
>This is GSM-R, Global System for Mobile Communications - Railway or
>GSM-Railway, for details see Wikipedia.
>500km/h would be good enough for us but not for others. We can forget it
>in aviation thanks to Doppler effect.
>
>Bear

Hmmm. The prime communications channels with the space station are digital.

DirecTV and Dish Network are digital. The network feeds to your TV stations
are digital via satellite. The "cable channels" are fed digitally to your
cable companies.

GPS is digital. It seems to be popular in aircraft.

Alan

[Bill D]

The present 2-meter AM air-band "Party line" originated as a military system in the biplane era. Today's military has many highly secure digital communication nets used for airborne operations from close air support to drone attacks.

The DOD likes the idea of using COTS products so wherever possible, they push military technology into the commercial domain to spread R&D costs and reduce the price they pay per unit. That's where the air-band replacement will come from.

Why would the FAA and ICAO want to do this? Bandwidth. Digital communication uses spectrum far more efficiently and it eliminates channel clutter so pilots hear just what they need to hear.

On Saturday, April 13, 2013 2:13:33 PM UTC-6, Bear wrote:
> What is your proposal?
>
>
>
> >
>
> > So, how is digital communication with 17,000 mph satellites possible with Doppler effects?
>
> >
>
> > Nobody suggested GSM as an alternative to a global aviation-specific digital communications protocol.
>
> >

[Kent Leyde]

http://en.wikipedia.org/wiki/Orthogonal_frequency-division_multiplexing

From wikipedia:

Summary of advantages
*High spectral efficiency as compared to other double sideband modulation schemes, spread spectrum, etc.
*Can easily adapt to severe channel conditions without complex time-domain equalization.
*Robust against narrow-band co-channel interference.
*Robust against intersymbol interference (ISI) and fading caused by multipath propagation.
*Efficient implementation using Fast Fourier Transform (FFT).
*Low sensitivity to time synchronization errors.
*Tuned sub-channel receiver filters are not required (unlike conventional FDM).
*Facilitates single frequency networks (SFNs); i.e., transmitter macrodiversity.


On Saturday, April 13, 2013 1:13:33 PM UTC-7, Bear wrote:
> What is your proposal?
>
>
>
> >
>
> > So, how is digital communication with 17,000 mph satellites possible with Doppler effects?
>
> >
>
> > Nobody suggested GSM as an alternative to a global aviation-specific digital communications protocol.
>
> >

[Darryl Ramm]

On Thursday, April 11, 2013 2:33:51 PM UTC-7, Paul Remde wrote:
> Hi,
>
>
>
> I imagine someone on this newsgroup can point me in the right direction on a
>
> technical/FAA question.
>
>
>
> Becker offers 2 versions of their AR6201 radio. The original version has
>
> frequency spacing that can be set to either 25 mHz or 8.33 mHz. The new,
>
> slightly lower cost option has frequency spacing fixed at 25 MHz It is my
>
> understanding that the 8.33 MHz spacing is required in Europe, but not
>
> currently in the USA. Customers are asking me whether the FAA has any plans
>
> to go to the 8.33 MHz spacing in the near future - so they can be better
>
> equipped to select the radio version that makes sense. At a recent soaring
>
> seminar someone stated that they thought the FAA was going to require radios
>
> with the 8.33 MHz spacing starting in 2020.
>
>
>
> Can anyone help me?
>
>
>
> Thank you in advance.
>
>
>
> Paul Remde
>
> Cumulus Soaring, Inc.

Yes Google would answer all your questions. 8.3 kHz ain't happening in the USA anytime soon. And one issue there is the FAA in their "wisdom" have been playing with Nextcom, a VDL based future digital voice system. (VDL is one of the existing digital link technologies that was also a potential ADS-B carrier, but is effectively not used for ADS-B).

http://www.aviationtoday.com/av/commercial/Are-We-Nearer-to-NEXCOM_1201.html

and see

http://www.roger-wilco.net/8-33-khz-channel-spacing-%E2%80%93-what-is-this/

Presumably would be introduced in transport category and other high-flying aircraft. Yes the same folks that thought going dual-link ADS-B was a good idea... your tax dollars at work, sigh. It would not surprise me to eventually see 8.3 kHz spacing in the USA, and that would actually be a good think IMNSHO vs. trying to go digital.

Any mentions of cellular communication standard here are irrelevant, terrestrial type cellular systems don't work well with aircraft in the air and "spamming" multiple cells. For digital links there are technology (like VDL) that are already fairly well understood. FM based systems (like FRS, which is low-power and also irrelevant here) are also non-starters, being FM does not inherently solve bandwidth issues and FM suffers from capture effect/overtalk issues (why we use AM to start with).

Darryl

[soartech[_2_]]

> and FM suffers from capture effect/overtalk issues (why we use AM to start with).
>
> Darryl

Darryl,
Please explain these terms. I always thought aviation used the
outdated AM because that's what they started with many years ago.
After having used 2 meter FM radios for many years I find them to be
vastly superior to aircraft band AM radios.

[Sean F (F2)]

This would be a great solution then to the team flying dilemma. Simply purchase a modern radio and fly on channels entirely unused on the USA.

Im ordering one today.

Sean
F2

[Mike the Strike]

Unfortunately those "unused" 8.3kHz channels don't actually exist - they are already occupied by the existing 25kHz channels. Also any radio you use to transmit here in the USA has to be type approved and current approval doesn't include the 8.3kHz units.

Sorry!

[Tony V]

On 4/24/2013 12:43 PM, soartech wrote:
>> and FM suffers from capture effect/overtalk issues (why we use AM to start with).
>>
>> Darryl
>
> Darryl,
> Please explain these terms. I always thought aviation used the
> outdated AM because that's what they started with many years ago.
> After having used 2 meter FM radios for many years I find them to be
> vastly superior to aircraft band AM radios.

The advantage of AM is that when two people talk at once you hear them
both. With FM, you get the strongest signal or, when both signals are
nearly equal in strength, you hear neither. I'll take AM for aviation
radio. For ham VHF/UHF, it's FM/SSB/digital. :-)

Tony "6N", W1DYS

[Darryl Ramm]

On Wednesday, April 24, 2013 4:31:35 PM UTC-7, Tony V wrote:
> On 4/24/2013 12:43 PM, soartech wrote:
>
> >> and FM suffers from capture effect/overtalk issues (why we use AM to start with).
>
> >>
>
> >> Darryl
>
> >
>
> > Darryl,
>
> > Please explain these terms. I always thought aviation used the
>
> > outdated AM because that's what they started with many years ago.
>
> > After having used 2 meter FM radios for many years I find them to be
>
> > vastly superior to aircraft band AM radios.
>
>
>
> The advantage of AM is that when two people talk at once you hear them
>
> both. With FM, you get the strongest signal or, when both signals are
>
> nearly equal in strength, you hear neither. I'll take AM for aviation
>
> radio. For ham VHF/UHF, it's FM/SSB/digital. :-)
>
>
>
> Tony "6N", W1DYS

What he said...

Darryl

[Eric Greenwell[_4_]]

On 4/24/2013 12:53 PM, Mike the Strike wrote:
> Unfortunately those "unused" 8.3kHz channels don't actually exist -
> they are already occupied by the existing 25kHz channels. Also any
> radio you use to transmit here in the USA has to be type approved and
> current approval doesn't include the 8.3kHz units.

I don't understand the claim of "not approved" status: quite a few 8.3
kHz spacing units are available for sale in this country, including
Becker AR6201 and MGL V6 (the unit I use). Are these illegal to use on
the standard 25 kHz spacings?

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[Mike the Strike]

Radios for sale in the USA should have switchable 25kHz/8.3kHz spacing so that they can be used in areas where either standard is used - but they are only currently legal to use in the USA with 25kHz spacing.

Mike

[Sean F (F2)]

On Wednesday, April 24, 2013 3:53:34 PM UTC-4, Mike the Strike wrote:
> Unfortunately those "unused" 8.3kHz channels don't actually exist - they are already occupied by the existing 25kHz channels. Also any radio you use to transmit here in the USA has to be type approved and current approval doesn't include the 8.3kHz units.
>
>
>
> Sorry!

poop!

[Bart[_4_]]

On Apr 24, 12:53*pm, Mike the Strike > wrote:
> Unfortunately those "unused" 8.3kHz channels don't actually exist - they are already occupied by the existing 25kHz channels.

I would be surprised if a "25kHz" radio actually used more than 4kHz
on each side of the carrier, interfering with the "unsused" channels.

BUT, I would be much less surprised if a "25 kHz" radio, especially an
older one, was adversely affected by a transmission made 8.33 kHz
away.

Bart

[Bart[_4_]]

On Apr 24, 4:31*pm, Tony V > wrote:
> The advantage of AM is that when two people talk at once you hear them
> both. With FM, you get the strongest signal or, when both signals are
> nearly equal in strength, you hear neither.

Plus, for weak signals, AM offers better signal to noise ratio. In
less technical terms, if pilot A has to really struggle to hear and
understand pilot B using AM, then pilot A would not hear anything if
they were using FM.

Bart