[ARC5] A-10 Radios
jeepp
jeepp at comcast.net
Wed Jul 11 21:17:56 EDT 2018
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
To: Jay Coward
Cc: Bob Macklin ; To: ARC-5 ;
Robert
Eleazer
Sent: Wednesday, July 11, 2018 2:10
PM
Subject: Re: [ARC5] A-10 Radios
Yes, the wiki says:
Originally from amateur radio, the phrase was used to
describe the way an FM transmitter will cut in
and out as it nears the capture threshold of a moving receiver or
transmitter as it passes through fresnel zones, 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
{KV6LEE(at)gmail(dot)com}
##
On Tue, Jul 10, 2018 at 4:09 PM Jay Coward <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>
To: macklinbob <macklinbob at gmail.com>
Cc: To: ARC-5 <arc5 at mailman.qth.net>; Robert Eleazer <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
{KV6LEE(at)gmail(dot)com}
##
On Wed, Jul 4, 2018 at 5:31 PM K5MYJ <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
To:
Scott Johnson
Cc:
arc5 at mailman.qth.net ; Robert Eleazer
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> 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
scott.johnson at ieee.org
From: arc5-bounces at mailman.qth.net <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
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
Virus-free.
www.avg.com
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