[ARC5] A-10 Radios
DSP3
jeepp at comcast.net
Thu Jul 12 16:44:40 EDT 2018
That's a very good question, Frank. Given the flight density statistics
published by the ICAO, I can see no genuine reason except that it does
triple the number of channels. With some exceptions, it required the
wholesale replacement of VHF radio sets. Some were adaptable via either
factory or field modification. The other factor is that in Europe,
aviation is a very high-dollar activity. Personal and business aircraft
are owned by a wealthy minority. Arguably, most light, gen-av aircraft
are owned and operated by flying clubs, rather than, as in the USA,
where private ownership is widespread. If regulators in Europe want
something, they generally get it. Here, in the USA, things don't go
quite so fast and without public comment. US two and three letter
carriers that fly to Europe are compliant and capable, of course. If it
were mandated here, over 79% of aircraft installations would need to be
replaced, wholesale. If/when 8.33 was mandated, I suspect that it would
be only the high altitude structure that would be (initially) affected,
as was in Europe. I don't know what the break-down would be as to
numbers of aircraft that operate above FL180, but the requirement for
pressurization, oxygen, et al sort of thins the herd to air carriers and
the business fleet, not that there aren't a bunch of other high-rollers
up there. Me and the Cherokee 180 will just be content to install
ADS-B, soon....
Jeep K3HVG
On 7/12/2018 10:46 AM, Francesco Ledda wrote:
>
> I don’t understand the need for the 8.33 kHz spacing, since the
> spectrum is not very crowded. Why such need? Anybody knows?
>
> Frank, K5URG
>
> *From:*arc5-bounces at mailman.qth.net
> [mailto:arc5-bounces at mailman.qth.net] *On Behalf Of *jeepp
> *Sent:* Wednesday, July 11, 2018 8:18 PM
> *To:* Robert Eleazer; Bart Lee; Jay Coward
> *Cc:* To: ARC-5
> *Subject:* Re: [ARC5] A-10 Radios
>
> Well, to be precise, US channel spacing for aeronautical VHF is
> currently 25 kHz. The Europeans currently use 8.33 kHz spacing for
> the high altitude structure, above FL195, shortly to be applicable for
> all altitudes. For the low altitude structure, 25kHz will get by, for
> a little longer. The thing is, general aviation in Europe is very
> small compared to the US and thus has minimal influence as to
> regulations.
>
> Jeep K3HVG
>
> Sent from my Verizon 4G LTE smartphone
>
>
>
> -------- Original message --------
> From: Robert Eleazer <releazer at earthlink.net>
> Date: 7/11/18 15:18 (GMT-05:00)
> To: Bart Lee <kv6lee at gmail.com>, Jay Coward <jcoward5452 at aol.com>
> Cc: "To: ARC-5" <arc5 at mailman.qth.net>
> Subject: Re: [ARC5] A-10 Radios
>
> The big factor is bandwidth. Aircraft frequencies are on a 5 KHZ
> spacing now. Move 5 khz on narrow FM and you are talking over someone
> else.
>
>
> Wayne
>
> WB5WSV
>
> ----- Original Message -----
>
> *From:*Bart Lee <mailto:kv6lee at gmail.com>
>
> *To:*Jay Coward <mailto:jcoward5452 at aol.com>
>
> *Cc:*Bob Macklin <mailto:macklinbob at gmail.com> ; To: ARC-5
> <mailto:arc5 at mailman.qth.net> ; Robert Eleazer
> <mailto:releazer at earthlink.net>
>
> *Sent:*Wednesday, July 11, 2018 2:10 PM
>
> *Subject:*Re: [ARC5] A-10 Radios
>
> Yes, the wiki says:
>
> Originally from amateur radio
> <https://wikivisually.com/wiki/Amateur_radio>, the phrase was used
> to describe the way an FM
> <https://wikivisually.com/wiki/FM_broadcasting> transmitter will
> cut in and out as it nears the capture threshold
> <https://wikivisually.com/wiki/Capture_effect> of a moving
> receiver or transmitter as it passes through fresnel zones
> <https://wikivisually.com/wiki/Fresnel_zone>, thus chopping the
> speech of the transmitting operator. It is not clear if the phrase
> was intended to describe the loss of the speech, or if it actually
> referred to the chopping sound itself, which imitates the noise
> produced by dragging a stiff object across a picket fence.
>
> I first heard the term all too many decades ago in the Civil Air
> Patrol, as just a quick explanation for why AM instead of FM
> in aviation. I have heard the effect on FM radio while driving.
> I think Jeep is right that it's lock-in more than anything else
> that keeps aviation radio in AM, other than for long distance
> communications where power matters, hence SSB.
>
> 73 de Bart, K6VK ##
>
> -- --
>
> Bart Lee
>
> Texts only to: 415 902 7168
>
> www.bartlee.com <http://www.bartlee.com/>
>
> {KV6LEE(at)gmail(dot)com} ##
>
> On Tue, Jul 10, 2018 at 4:09 PM Jay Coward <jcoward5452 at aol.com
> <mailto:jcoward5452 at aol.com>> wrote:
>
> Hi Bart,
>
> Isn't this also known as "picket fencing" from multipath
> reception?
>
> Jay KE6PPF
>
> -----Original Message-----
> From: Bart Lee <kv6lee at gmail.com <mailto:kv6lee at gmail.com>>
> To: macklinbob <macklinbob at gmail.com
> <mailto:macklinbob at gmail.com>>
> Cc: To: ARC-5 <arc5 at mailman.qth.net
> <mailto:arc5 at mailman.qth.net>>; Robert Eleazer
> <releazer at earthlink.net <mailto:releazer at earthlink.net>>
> Sent: Tue, Jul 10, 2018 2:00 pm
> Subject: Re: [ARC5] A-10 Radios
>
> FM received by a mobile (or air mobile) vehicle can
> "washboard" the received signal as the moving vehicle hits the
> incoming radio waves. Car radios on FM frequently have this
> issue. Aviation AM may or may not have been selected to avoid
> this problem, at 135 MHz and below. AM was the way aviation
> radio started, so there was some lock-in, especially after
> Curtis LeMay selected single sideband for SAC in the early
> 1950s. SSB's power advantages may also have come into play.
> 73 de Bart, K6VK ##
>
> -- --
>
> Bart Lee
>
> , K6VK, CHRS, AWA, ARRL
>
> Texts only to: 415 902 7168
>
> www.bartlee.com <http://www.bartlee.com/>
>
> {KV6LEE(at)gmail(dot)com} ##
>
> On Wed, Jul 4, 2018 at 5:31 PM K5MYJ <macklinbob at gmail.com
> <mailto:macklinbob at gmail.com>> wrote:
>
> The reason for the use of AM in aviation is you can hear
> when somone doubles. Not so with FM.
>
> The reason of low band FM is to communicate with the
> troops on the ground.
>
> I was in Korea in 1953. We used AT-6s for FAC operations.
> Our AT-6s had ARC-5 VHF radios.
>
> The people on the ground had ARC-3s in jeeps.
>
> Bob Macklin
> K5MYJ
> Seattle, Wa.
> "Real Radios Glow In The Dark"
>
> ----- Original Message -----
>
> *From:*Peter Gottlieb <mailto:kb2vtl at gmail.com>
>
> *To:*Scott Johnson <mailto:scottjohnson1 at cox.net>
>
> *Cc:*arc5 at mailman.qth.net
> <mailto:arc5 at mailman.qth.net> ; Robert Eleazer
> <mailto:releazer at earthlink.net>
>
> *Sent:*Wednesday, July 04, 2018 2:45 PM
>
> *Subject:*Re: [ARC5] A-10 Radios
>
> In a practical sense for any of us the question might
> be whether in regular AM and FM use the radio performs
> any better than other radios. The answer is probably not.
>
> Peter
>
>
> On Jul 4, 2018, at 12:45 PM, Scott Johnson
> <scottjohnson1 at cox.net <mailto:scottjohnson1 at cox.net>>
> wrote:
>
> Most all USAF tactical assets now have the
> ARC-210, which covers all the military bands and
> modes from 30-512 MHz, and has built in ECCM and
> secure speech, as well as satcom capability (all
> with the proper antennas and switching, of
> course). It is an awesome radio, but at $100K a
> copy, not on my wish list. Like the ARC-164, it
> will probably soldier on for at least thirty years
> (it’s already about fifteen years old, but
> evolving, just like the -164)
>
> Scott V. Johnson P.E. W7SVJ
>
> Sunburst Engineering Partners
>
> 5111 E. Sharon Dr.
>
> Scottsdale, AZ 85254-3636
>
> H (602) 953-5779
>
> C (480) 550-2358
>
> scottjohnson1 at cox.net <mailto:scottjohnson1 at cox.net>
>
> scott.johnson at ieee.org <mailto:scott.johnson at ieee.org>
>
> *From:*arc5-bounces at mailman.qth.net
> <mailto:arc5-bounces at mailman.qth.net>
> <arc5-bounces at mailman.qth.net
> <mailto:arc5-bounces at mailman.qth.net>> *On Behalf
> Of *Robert Eleazer
> *Sent:* Tuesday, July 3, 2018 9:55 AM
> *To:* arc5 at mailman.qth.net
> <mailto:arc5 at mailman.qth.net>
> *Subject:* [ARC5] A-10 Radios
>
> When I was at the Pentagon the idea was to get rid
> of the A-10 and use F-16's. The F-16 equipped
> with a weapons load comparable to an A-10 could do
> a very nice job of making sure no one got past
> the guard shack at the main gate of its home base.
>
> The fear was that the A-10 was so slow that when
> the Warsaw Pact came through the Fulda Gap the
> A-10 would get hit on the first day of the war and
> although probably survive to make it home but we
> would not have time to repair it before the war
> was over.
>
> Some on Congress said that if USAF got rid of the
> A-10 the US Army should take over the airplane, it
> being a much better "mud mover." The Army was
> terrified, saying that all their airplanes had to
> have at least two seats.
>
> Then came Saddam's invasion of Kuwait and the A-10
> was the machine to have. And when the war was
> over we had lost four A-10's and four F-16's So
> much for survivability concerns. A re-engining
> program was started for the A-10 a few years
> later. And the USSR went out of business on 25 Dec
> 1991; so much for the Fulda Gap concern
>
> To some in the USAF was faced with either keeping
> the A-10 or buying the F-35 - and the F-35 won.
> I do not know if that insanity persists.
>
> The A-10 would have at a minimum VHF AM Air Band
> (108-132 MHZ), UHF AM (220-400 MHZ), and low band
> FM (30-76 MHZ) radios. The ARC-114, ARC-115, and
> ARC-116 such as carried by US Army helicopters of
> the late 60's would do nicely but it no doubt
> has gear later than that.
>
> Anyway, look it up yourself. The pilot's manual
> for the A-10 is available for free download here:
>
> http://www.476vfightergroup.com/downloads.php?do=file&id=42
>
> Wayne
>
> WB5WSV
>
> *Error! Filename not specified.*
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>
>
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