[ARC5] A-10 Radios
MICHAEL ST ANGELO
mstangelo at comcast.net
Thu Jul 12 14:30:46 EDT 2018
Isn't FL 195 shorthand for flight level 19,500 feet?
Mike N2MS
> On July 12, 2018 at 12:59 PM Robert Downs via ARC5 <arc5 at mailman.qth.net> wrote:
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> If you mean why 8.333… spacing because there is no need for that many channels, they are presumably looking ahead a few decades. If you mean why that wide a spacing (instead of for example 5 KC spacing, remember how radios really work. The audible bandwidth may only be 6 KC or even 5.6 KC but both overlap at the output of the IF strip or whatever has replaced it, which will cause audible interference between radios on adjacent channels. But remember that the effective bandwidth of the front end isn’t that tight. Which although you may not be able to hear much from the adjacent channel, the receivers may be desensitized by the wider signal getting into the front end. Remember that we are talking about DSBAM, not SSBSC. And in fact, I would question the viability of 8.333 KC spacing.
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> On another subject, I thought that the whole numbers of a flight level were the altitude in thousands of feet. I don’t know of anything except unmanned vehicles in at least the unclassified inventories at present capable of reaching FL 195 except for some Russian launch vehicles. Unless I’m mistaken, that is almost 37 miles.
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> Robert Downs
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> From: arc5-bounces at mailman.qth.net [mailto:arc5-bounces at mailman.qth.net] On Behalf Of Francesco Ledda
> Sent: Thursday, July 12, 2018 09:47
> To: 'jeepp'; 'Robert Eleazer'; 'Bart Lee'; 'Jay Coward'
> Cc: 'To: ARC-5'
> Subject: Re: [ARC5] A-10 Radios
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>
> I don’t understand the need for the 8.33 kHz spacing, since the spectrum is not very crowded. Why such need? Anybody knows?
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> Frank, K5URG
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> 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.
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> Jeep K3HVG
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> Sent from my Verizon 4G LTE smartphone
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> -------- 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:
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> >
> >
> > 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.
> >
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> > 73 de Bart, K6VK ##
> >
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> >
> >
> >
> > -- --
> >
> > Bart Lee
> >
> >
> >
> > Texts only to: 415 902 7168
> >
> > www.bartlee.com http://www.bartlee.com/
> >
> >
> >
> > {KV6LEE(at)gmail(dot)com} ##
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> > 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} ##
> > >
> > >
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> > >
> > > 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.
> > > > >
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> > > > >
> > > > > 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 http://www.476vfightergroup.com/downloads.php?do=file&id=42
> > > > > >
> > > > > > Wayne
> > > > > >
> > > > > > WB5WSV
> > > > > >
> > > > > > Error! Filename not specified. http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient
> > > > > >
> > > > > > Virus-free.http://www.avg.com
> > > > > >
> > > > > > > > > > >
> > > > > > > > > > >
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