History Podcasts

Speed AM-116 - History

Speed AM-116 - History


We are searching data for your request:

Forums and discussions:
Manuals and reference books:
Data from registers:
Wait the end of the search in all databases.
Upon completion, a link will appear to access the found materials.

Speed

(AM-116 : dp. 890 1. 221'2 ; b. 32'; dr. 10'9 ; s. 18 k.; cult 105, a. i 3~, 2 40mm., 4 20mm., 4 dcp., 1dcp. (hh.), 2 dct.; cl. Auk)

Speed was laid down at Cleveland, Ohio, on 17 November 1941 by American Ship Building Co.; launched on 18 April 1942; and commissioned on 15 October 1942, Comdr. Ernest L. Posey in command.

Departing Cleveland on 15 November, Speed proceeded to Boston, Mass., where she arrived on 8 December. During the next three months, she conducted shakedown and training along the Atlantic Coast from Casco Bay, Maine, to Norfolk, Va., before departing New York on 19 March 1943 for the Mediterranean. As escort for an eastbound convoy, she sailed via Bermuda and arrived at Tunis, Tunisia, on 13 April.

Assigned to Mine Division 17, Speed conducted coastal patrols off the coast of Algeria during the next two months. On 5 July, she departed Mers-el-kebir, Algeria, and joined Vice Admiral H. K. Hewitt's Western Naval Task Force for the invasion of Sicily. Steaming with ships of Task Force 85, she closed the Sicilian coast off Scoglitti on 10 July and served as a control ship during amphibious assaults.

Following the invasion, Speed swept waters along the southern and western coasts of Sicily. After sweeping off Palermo, she escorted supply convoys between Tunisia and Sicily from 10 to 23 August. On 25 August, she sailed for Algeria and arrived at Oran on the 29th to prepare for the invasion of Italy.

As a unit of Rear Admiral J. L. Hall's Southern Attack Force, Speed departed Oran on 5 September and arrived off the Gulf of Salerno late on 8 September. She swept channels during the landings the next day and operated in the Gulf of Salerno on mine and antisubmarine patrols until 26 September. While on patrol on the 25th, she rescued survivors of Skill (AM-115) after that minesweeper had been fatally hit by an enemy torpedo.

Speed departed Salerno on 26 September and escorted a convoy of merchant ships to Bizerte, Tunisia. Interspersed with minesweeping and ASW patrols, she performed escort duties during the next nine months as she screened supply and reinforcement convoys from North Africa to Sicily and Italy. While steaming in convoy from Oran to Bizerte on 20 April 1944, she helped repulse a determined German air attack which sank three ships, including Lansdale (DD-426).

After returning to Naples on 20 June, Speed operated in the Gulf of Salerno until 7 August preparing for the invasion of southern France. Assigned to Task Force 87, she departed Salerno on 12 August and escorted an LCI convoy to the assault area off Frejus and St. Raphael. She closed the French coast early on 15 August and served as a glider bomb "jam ship" and in the ASW screen during amphibious landings. She operated along the French coast during the next few weeks, sweeping channels and clearing harbors from Frejus to Toulon. After two escort runs to North Africa, she departed Oran for the United States on 24 November and arrived at Norfolk on 11 December to begin a two-month overhaul.

Speed departed Norfolk on 15 March 1945 for minesweeping duty in the western Pacific. Steaming via the Panama Canal and San Diego, Calif., she reached Pearl Harbor on 31 May. Between 11 June and 12 July, she steamed to Okinawa via the Marshall and Marianas Islands. Assigned to Mine Squadron Six, she swept the waters of the Ryukyus during the closing weeks of World War II. After the end of hostilities she departed Okinawa on 1 September for sweeping operations along the coast of Japan. Arriving at Kagoshima, Kyushu, on 3 September, she swept Kagoshima Wan and Van Diemen Strait before returning to Okinau-a on 13 September.

During the remainder of 1945, Speed continued minesweeping operations in support of the Allied occupation of Japan. Her duties carried her to Bungo Suido and the Inland Sea, as well as to the East China Sea and waters off Formosa. She returned to the United States early in 1946, was decommissioned on 7 June, and entered the Pacific Reserve Fleet at San Diego. She was reclassified MSF-116 on 7 February 1955. On 17 November 1967, Speed was transferred to the Republic of Korea, and she served the Korean Navy as Sunchon (PCE-1002).

Speed received seven battle stars for World War II service.


Burlington's "Zephyr 9900" Streamliner

It was originally designed as a three car trainset with an overall length somewhat shorter than the M-10000.  However, its marketing campaign wowed the public when it traveled non-stop from Denver to Chicago in record time.  

The PR move worked beyond the railroad's wildest expectations and it was quickly forced to add more cars and purchase new trains.  These new trains also carried the Zephyr moniker and were equally successful. 

All of the railroad's early articulated trainsets were retired by the late 1950s as newer, non-articulated locomotives and cars replaced the aging Zephyrਏleet. However, their legacy has certainly not been forgotten and the original remains preserved today.

This photo was quite famous at the time but has since faded into relative obscurity. It was taken by the Chicago Tribune, directly after the train completed its historic non-stop run from Denver to Chicago on May 26, 1934. Featured in the picture were those aboard, as well as the mascot burro "Zeph."

The Burlington Route's Pioneer Zephyr was the concept of the railroad's then president Ralph Budd. Interestingly, soon after joining the company, Budd began to brainstorm on the idea of building a lightweight, fast, and stylish passenger train that was powered by a diesel engine.

As it turns out the new streamliner would go down in history as the first ever powered by such a prime mover. Budd's idea for using a diesel dated back to the 1920s where he first saw them employed in early small switchers of the time (probably one of the first boxcab models).

Related Reading.

However, the Burlington Zephyr (as it was originally called, named after the Greek god of the West Wind, Zephyrus) also needed a sleek carbody in which to dazzle the public and passengers.

The streamlined look of the Zephyr would never have been possible without the recent development of shot-welding, another patented concept the Budd Company mastered.

This version of welding enabled stainless steel to be welded together using high amp electric current that actually created a bond stronger than the steel itself.

Now able to mold, bend, and form stainless steel into whatever shape it wanted Budd could design an endless types of railroad equipment. 

And it certainly exploited this advantage as much as possible allowing Budd to become a major competitor against Pullman, as it was the only company producing flashy stainless steel equipment.

A Chicago, Burlington & Quincy's "Zephyr" trainset is seen here at rest in Lincoln, Nebraska, circa 1944. As the story goes the train was given its name by CB&Q president Ralph Budd, who read Geoffrey Chaucer's, "The Canterbury Tales," and learned Zephyrus was the Greek God of the West Wind.

Officially, the CB&Q placed an order from Budd for the Zephyr on June 17, 1933 for a three-car, articulated trainset that would be powered by a 660 horsepower model 201-A prime mover from Winton. While Budd could fabricate the carbody, somebody actually had to come up with a design.

That was tasked to Albert Dean, an aeronautical engineer who worked for the company. His design featured a shovel nose power car that included a significantly raked lead windshield. The entire train was sheathed in stainless steel and one could barely even see the wheel assemblies.

If the train itself looked stylish and futuristic it was in large part due not only to the lead power car and fluted stainless steel but also because of the observation car.

A completely new way to give a passenger train a "finished" look the observation was a round-ended affair, completing the streamlined look.

Inside the train the features were subtle but elegant due to the fact that the train was meant to be a "dayliner", regional train only. Much of its interior was of Art Deco design and the observation car was largely decorated by John Harberson of Philadelphia.

Overall, the train was 197 feet long and could hold 72 passengers, 44 fewer than the Union Pacific's M-10000. Its consist included a Railway Post Office (RPO), baggage-coach, and a coach-parlor observation.

It is somewhat fascinating that for a train that was only supposed to be regional in nature that the company since so many resources on its development. Of course, while extremely expensive in comparison to a traditional train of the time it not only proved to be widely successful but also offered much lower maintenance costs.

No date of information was provided with this photo but it was likely taken soon after the "Zephyr 9900" trainset rolled out of Budd's plant near Philadelphia in April, 1934.

On April 7, 1934 the Burlington Zephyr਎xited Budd's plant near Philadelphia and two days later on April 9th made its first test runs of the Reading Railroad reaching speeds as high as 104 mph.

Nine days later on April 18 the train was debuted to the public at Broad Street Station in Philadelphia and the public was awestruck.

About a month later, on May 10th the train reached Chicago although along the way it toured Cincinnati, Cleveland, Pittsburgh, Detroit, Buffalo, and Washington, D.C. After returning to Burlington's rails the train continued to be featured to the public, wowing audiences as it went. 

Much of the success of the Pioneer, and its historical fame, can be greatly attributed to its incredibly popular public appearances it made during the spring of 1934 (much more so than the UP's M-10000).

Its legendary status was further cemented by the events which occurred on the morning of May 26th at 5:05 A.M. At that time the Zephyr officially left Denver on its way to Chicago. 

The "Pioneer Zephyr" was an immediate public sensation and the affluent CB&Q spent heavily advertising its "Zephyr" fleet, which enjoyed many years of strong patronage.

Averaging a speed of 78 mph it arrived in the Windy City at 7:10 P.M. that same evening covering a distance of 1,015.4 miles. The public was further amazed and it didn't hurt that that very evening the Progress World's Fair Exposition was ongoing.

In September, 1934 the train was used in the filming of Silver Streakਊnd did not actually begin regularly scheduled service on the Burlington until November 11 of that year.  

This particular advertisement provided the general public with a great deal of technical data regarding its new "Zephyr" streamliner.

According to Mike Schafer and Joe Welsh's Streamliners: History of a Railroad Icon when touring had completed of the Zephyr it had traveled 30,437 miles, been featured in 222 cities, and was seen by over two million people.

After the train entered service it even defied the railroads expectations, earning a profit when the Burlington believed that it never would. In June, 1935 a dinette-coach was added to the train, which increased ridership to 112. 

Pioneer Zephyr/Zephyr 9900 Timetable

Read Down Time/Leave (Train #21) Milepost Location Read Up
Time/Arrive (Train #20)
2:30 PM (Dp)0.0 Kansas City, MO (Union Station) 12:55 PM (Ar)
2:58 PM26 East Leavenworth, MO 12:20 PM
3:24 PM46 Armour, MO 11:58 AM
3:47 PM (Ar)64 St. Joseph, MO (Union Depot) 11:34 AM (Dp)
3:53 PM (Dp)64 St. Joseph, MO (Union Depot) 11:28 AM (Ar)
103 Bigelow, MO 10:49 AM
110 Craig, MO F 10:40 AM
116 Corning, MO 10:34 AM
4:50 PM126 Langdon, MO 10:23 AM
5:10 PM143 Hamburg, IA 10:05 AM
5:21 PM150 Payne, IA 9:55 AM
6:03 PM192 Council Bluffs, IA 9:14 AM
6:09 PM193 Council Bluffs Transfer, IA 9:14 AM
6:20 PM (Ar)196 Omaha, NE 9:00 AM (Dp)
7:00 PM (Dp)196 Omaha, NE 8:25 AM (Ar)
7:55 PM (Ar)251 Lincoln, NE 7:30 AM (Dp)
Notable photographer Jack Delano captured a World War II-era "Zephyr" trainset under Chicago Union Station's enormous covered platforms in January, 1943.

As mentioned above the Burlington Zephyr was renamed as new trainsets were purchased giving it the Pioneer Zephyr moniker (or known as the Zephyr 9900 by its original numbering).  

In total, eight more trainsets were purchased, #9001-#9008: #9001 and #9002 were referred to as the Morning Zephyr and Afternoon Zephyr (or the Twin City Zephyrs) #9003 as the Mark Twain Zephyr #9004 and #9005 as additional Twin City Zephyrs #9006 and #9007 as the Denver Zephyrs and #9008 as the General Pershing Zephyr.

Of course, there were other trains with the Zephyr name as well such as the California Zephyr, Nebraska Zephyr, and Kansas City Zephyr which were standard-diesel powered/passenger car trains. Today, the original is on display at Chicago's Museum of Science and Industry.


Speed AM-116 - History

Moonbounce for the Rest of Us

PART I - INTRODUCTION, OPERATIONAL BASICS AND PROPAGATION

The purpose of this article is to provide radio amateurs with enough background information to understand the technical challenges involved in "small-station" digital EME on the 144 and 432 MHz bands. Suggested configurations, approximate costs and operational potential will be included, all with the goal of encouraging amateurs to consider EME by showing that it is neither excessively complex from a technical perspective nor prohibitively costly when compared to other amateur activities. The article also includes a brief overview of the author's operational success to date.


Since the first successful amateur radio two-way EME (Earth-Moon-Earth or "moonbounce") communications in the early 1960s, EME has been regarded as the pinnacle of technological challenge as well as an activity requiring substantial financial resources. The latter is due to the necessity of overcoming the huge path loss (

250 dB) involved in sending a radio signal to the Moon and back. Initially this meant a massive antenna array, full legal transmit power, and state-of-the-art technology to attain the lowest possible receiver noise figure. Achieving all of these goals still meant that only CW contacts were possible because of the faint return signals, sometimes buried in noise, which required excellent hearing to detect.


Beginning in the 1970s, however, several things happened to begin to make EME possible for those with somewhat lesser capabilities (and with less expenditure):

1. The gradual development around the world of EME "super-stations" having huge arrays and the best state-of-the-art equipment that money could buy, allowing them to complete EME CW contacts with many less-well-equipped stations.

2. The development of the gallium-arsenide field-effect transistor (GAsFet) and other devices that made significantly lower noise figure VHF/UHF preamplifiers practical.

3. The development of high-quality affordable coaxial cable with lower loss at VHF & UHF.

4. The publication of practical designs for VHF and UHF kilowatt amplifiers that a reasonably technically-astute ham could build.


While the above technological improvements made EME more affordable and "do-able" by more hams willing to take on the challenges, it wasn't really until the development in the late 1990s of the WSJT series of digital transmission protocols by Joe Taylor, K1JT, that "everyman" use of the more esoteric weak-signal VHF/UHF communications modes - meteor scatter and EME - started to become more practical and affordable. These digital protocols allow the reception and accurate decoding of signals far below the noise level, as low as -24 dB and sometimes beyond.


While VHF meteor scatter was always possible during the major meteor showers - especially on CW - for anyone with a good Yagi antenna and 100 watts of power, the WSJT JT6M and FSK441a protocols fulfilled the dream of 50 and 144 MHz QSO completions using random daily meteors i.e., the thousands of "grain of sand" micrometeoroids that enter the atmosphere every day and create usable ionized trails of 100 milliseconds or less. The near-simultaneous development of the WSJT JT44 and JT65 (a, b and c) protocols did much the same for EME that JT6M and FSK441a did for meteor scatter. It is now possible for an amateur with 100 watts and a single Yagi with at least 12 dB gain to work any of the really large EME stations and, when conditions are favorable, some of the more modest stations as well. For a single-Yagi EME station to successfully contact a 4-Yagi station still requires excellent conditions, skillful operating and a bit of luck, but it is being be done on 144 MHz.


Because of the increasing popularity of EME any ham with a modest station somewhat larger than the "minimum" to be described can, through perseverance, achieve EME DXCC and some operators have completed EME WAS. Even a station such as the one described should be able to accumulate enough "grid squares" by means of meteor scatter and EME to augment terrestrial operation and qualify for 144 MHz VUCC (and using EME, even 432 MHz!) without raising a tower or running full legal power.

EME OPERATIONAL CHARACTERISTICS & LUNAR AVAILABILITY


It is important that anyone interested in EME understand the "operational characteristics" of using the Moon as a reflector for two-way communications. Below is a short list of the major concerns.

1. BOTH STATIONS MUST "SEE" THE MOON. This may seem like a superfluous statement but it bears repeating that the Moon *MUST* be above the horizon at both ends of an EME QSO.

2. The Moon's position changes daily and the rising & setting times advance day by day by about a half-hour to an hour depending on the time of the month. This will impact potential operating times and depending on personal schedule may limit one's "on-air" availability.

3. Due to the Moon's rotational schedule relative to sources of celestial noise and the Sun the Moon is only available and useful for EME operation for about 20 days per month.


The two illustrations that follow should give a pretty good idea of how the Moon's usefulness for making two-way EME contacts varies over a one-month period. The first illustration is a table of Moon rise and set times and the corresponding azimuth of the Moon for each. You can access the table for May, 2013, at the link below and just enter the desired month and year in the appropriate boxes.


The second illustration is a screen shot of the EME display window at the "Make More Miles on VHF" web page at http://www.mmmonvhf.de/eme.php . This particular shot is also for the month of May, 2013, but can be changed by entering a different month & year.


The first thing you should note from the table is that the Moon rises later and later each day. This means that if you cannot adjust your antenna in elevation and/or wish to take advantage of any "ground gain" (described later) by operating at Moonrise or Moonset you will be doing it anywhere from approximately 30 to 60 minutes later each successive day depending on the day of the month.


The screen shot shows the Moon's Distance (yellow line), Declination (blue line) and Degradation (red line) and is useful for determining what days are best for attempting operation. The smaller degradation peak occurs when the Moon is roughly coincident with the Sun, while the very large peak occurs when the Moon is passing in front of the Milky Way, a *HUGE* source of galactic noise! The best days for small stations occur when the Degradation is 2.5 dB or less. It is possible to have some success with the larger stations at degradations of 3 dB or so but when the degradation is above 4 dB it is going to be very, very tough to make QSOs - not because you cannot copy stronger stations, but because your "small station" signal is normally right at the decoding limit and any small amount of additional noise will push your signal into oblivion. Using this description of limitations you can see that for the month of May, 2013, the Moon is potentially usable for a small station from May 1 - 8 (8 days), May 16 - 24 (9 days), and May 28-31 (4 days) for a total of 21 days, although actual "useful days" will likely be fewer.


While the above are useful tools for helping you to decide when to plan your EME operation, there are still propagation issues that can nullify your attempts even on the best of days. When you are running a single Yagi at low power there will be times when you will get absolutely nowhere, but don't be too discouraged just be patient and keep trying, and you *WILL* make QSOs!

PROPAGATION ISSUES WITH EME


There is little debate among those who have "taken the plunge" in EME that the propagation challenges can be both formidable and unpredictable. Over the decades many hams have labored tirelessly to try and quantify, to the extent that such is possible, the vagaries of propagation associated with bouncing radio signals off of our nearest neighbor in space. What follows are some short descriptions of what these phenomena are and how they can affect the EME equation.

Orbit (Perigee - Apogee)


The Moon orbits the Earth approximately once every 28 Days in a slightly elliptical orbit. At Perigee (the closest the Moon approaches the Earth) the 144 MHz path loss approaches 251.5 DB at Apogee the value reaches 253.5 DB. Believe it or not, this 2 dB variation can mean the difference between completing a QSO or not when other factors drive signal levels down.


As the signal passes through the Ionosphere it rotates in polarity both on the way up and on the return bounce. The amount and speed of the rotation are always shifting and are unpredictable. When using arrays of fixed polarity (such as horizontal, which is most common) it is necessary to wait for the polarity to rotate into phase for reception. At times this never happens and you are effectively locked out, regardless of how large your station antenna array may be. This is due to up to 20 dB difference between vertical and horizontal polarization. Attempting to contact another station complicates the situation even more as now the signal must pass through two different ionospheric areas before arriving at either antenna.


First proposed by KL7WE and K9XY in 1984, this phenomenon is the reason why stations are audible at one location and not another. Imagine you are on the Moon looking at North America a station there using horizontal polarization is pointed at you and his wavefront arrives horizontal. Now look at the station in Europe using horizontal polarization and compare his wavefront to that of the North American station and you will see that they appear to be out of phase. At times the two polarities are 90 Degrees out of phase and thus 20 DB down from one another. That is far too much for the average EME station to overcome so no QSO takes place - EXCEPT for Faraday rotation, which can rotate the wavefront into the proper polarity and allow contact to be made. The fact is that due to the Spatial Polarity effect, without Faraday rotation most EME contacts would never happen.


There is a random fading effect on signals received off of the Moon caused by the rocking motion of the Moon and the signal wavefront bouncing off of the Moon's jumbled surface and taking on an irregular shape itself. The distorted wavefront is now full of peaks and nulls which sometimes add up in phase although on the average they give a 7% Pi-R-Squared reflectivity. However, when the phase additions occur the overall path loss can be REDUCED by as much as 6 to 10 DB.


As the Moon travels in its orbit the surrounding sky is filled with the random radio frequency noise emitted by all of the stars and galaxies. Some celestial bodies are noisier than others and any additional noise adds up as so many DB of degradation to your system. Measured in degrees Kelvin it can vary from 170 or so to as much as 3000+ degrees. The Milky Way is by far the biggest contributor and when the Moon is in its vicinity communications is impossible even for the largest stations. When the Moon is near the Sun there is also more noise so those days may be unusable as well. It should be noted that on 432 Mhz and above celestial noise poses less of a problem as the sky temperature in degrees K goes down in proportion to an increase in frequency.

When a radio wave from a distant source such as the Moon reaches the ionosphere the phase surface of the wave is distorted by irregular patches of varying refractive index. Since these patches are constantly moving the result is an interference effect resulting in fading known as Amplitude Scintillation. This is analogous to the visual "twinkling" of the light arriving from stars. It is possible for the effect to be additive and when this occurs it can result in up to 10 dB of non-reciprocal enhancement of an EME signal.


At Moonrise the Doppler effect between the Earth and Moon at 144 MHz will cause the echos to appear 300 Hertz or so higher in frequency. As the Moon traverses the sky to a point due south the Doppler approaches zero, and as the Moon continues westward the echos shift up to 300 Hertz lower in frequency at Moonset. This can pose a problem for the operator who answers a CQ where he/she is hearing the station but is not allowing for Doppler and is calling a station using very narrow filter bandwidth. The solution is to always shift the receiver RIT to correspond to the Doppler (which is indicated by the JT65b operating window on the computer).

Moonrise / Moonset - 6 dB Ground Gain

In North America the best time to operate is at or near Moonrise, not only to take advantage of the extra 6 dB of ground gain (which will make a single Yagi perform like four) but also because that is the optimum time to work European stations. Europe has by far the largest number of EME capable stations in the world, many having eight Yagis or more, so from Moonrise to about +15 degrees elevation a single Yagi station in the eastern U.S. can hear and work many European stations with only 100 Watts and at least 12 dBd antenna gain, other propagation conditions permitting.

In Part II we'll take a look at how a "beginner"144 MHz EME station might be configured, what it will cost, and how the K4MSG EME station was initially configured.

Moonbounce for the Rest of Us

PART II - A BASIC 144 MHz EME STATION

STATION REQUIREMENTS
-->
This section begins with an outline of station requirements because for many readers the bottom line is going to be - well, the "bottom line." Later on I'll discuss the details of how my station is assembled and outline the basic set-up requirements, but if the projected costs discussed in the following paragraphs are too much of a "turn-off" for any reader to consider then there is no point in him or her going beyond this part.

Based on a lot of study and my own practical experience a reasonable "minimum station" for achieving successful 144 MHz EME digital communications with larger stations would look something like the following. It can be done with less, but for repeatable success this list is probably a reasonable yardstick to use.

1. A VHF multimode transceiver capable of 144 MHz SSB operation, with output sufficient to drive an outboard amplifier. IF A HIGH STABILITY REFERENCE OSCILLATOR OPTION IS AVAILABLE IT WOULD BE PRUDENT TO PAY THE EXTRA MONEY FOR THIS CAPABILITY. In Digital EME as in so many other things in life, "timing is everything."

2. A combination power amplifier & low-noise preamplifier (aka a "brick") having a power output of 100 watts or more and a preamplifier noise figure of less than 1 dB (and the lower, the better ). THE UNIT SHOULD BE INSTALLED AT THE ANTENNA. (NOTE: Don't panic, this is much easier than it sounds.)

3. A DC power supply to be situated outside to power the amp/preamp.

4. A Yagi antenna with a forward gain of at least 12 dBd. THE ANTENNA ONLY NEEDS TO BE MOUNTED 7 TO 10 FEET ABOVE THE GROUND.

5. A small rotor for azimuth adjustment of the antenna (a TV rotor will suffice) is recommended although manual azimuth adjustment can be used if not too much of an annoyance. Some form of elevation adjustment is recommended, even if only manual, but EME contacts can be made during the first hour after Moonrise or the last hour prior to Moonset without it.

6. The shortest possible (50 feet or less is a good rule of thumb) low-loss coax between the transceiver and the amp/preamp. "Low loss" means, AT A MINIMUM, Belden 9913. LMR-400, EcoFlex 10 Plus and AirCom Plus are better still.

7. A radio/PC interface controller such as a Rigblaster by West Mountain Radio.

8. A desktop or laptop PC installed at the operating position. Windows XP or later are recommended operating systems, and WSJT Version 9 (which is FREE from the WSJT website) should be installed.

9. An accurate time-stabilization program (such as Dimension 4, which is also free) should be installed on the PC.

Here is how the basic costs break down:

1. TRANSCEIVER: Whatever you choose to spend.

2. AMP/PREAMP: Up to $450 new depending on brand less if purchased used.

3. POWER SUPPLY: Up to $200 for a new linear-type. I paid $105 shipped for a new MFJ switcher (compact, reliable, and there are *NO* noise problems with it!).

4. ANTENNA: $225- $250 including shipping and/or local sales tax (if bought from HRO).

$60-$120 depending on type and length.

7. INTERFACE UNIT: $160 for a Rigblaster Plus II.

8. PC/LAPTOP: Whatever you choose to spend.

9. WSJT and Dimension 4 software: FREE


The bottom line of the above list is that, discounting the transceiver, power supply in the shack and the PC, the remainder of the equipment for 144 MHz digital EME can be purchased for around $1,300 (BOLD-FACED maximum prices above). By judicious shopping and using eBay, eHam classifieds, etc., this can be cut considerably and if you already have some of the equipment the cost will be even less.

THE K4MSG 144 MHZ DIGITAL EME STATION

1. Icom IC-706MkIIG transceiver with a Dell laptop running Windows XP Professional, loaded with WSJT Version 9 and Dimension 4 time synchronization programs. A Rigblaster Plus interfaces the radio with the laptop. The laptop also utilizes a wireless connection to a home router for Internet connectivity for the Dimension 4 software and for monitoring the N0UK EME Chat Page this last is useful for setting up QSO attempts in real time if prior scheduling hasn't been done.

2. A M2 2M9SSB 9-element Yagi (14.5' boom) mounted on a home-made wood tripod with a TV rotor for azimuth control and a homebrew manual elevation adjustment.

3. A TE Systems 1412G 200-watt, 144 MHz amplifier/preamp (0.5 dB preamp noise figure) located at the antenna. Approximately 13 feet of AirCom Plus which was in the junk box connects the amplifier to the antenna, but EcoFlex 10 Plus has almost the same characteristics. An MFJ-4230MV 13.6 VDC metered, variable 30-amp power supply is co-located with the amplifier. The metered supply provides a visual check on whether the amplifier is keying during transmit cycles (by walking outside and noting the current draw on the supply meter) and the variable output allows adjustment of the DC output voltage to compensate for AC voltage drop through the extension cord from the house to the antenna. Note that this power supply is no longer manufactured but I found a source of brand-new in-the-box units on eBay for $105 shipped.

4. Initially, 50 feet of Belden 8214 low-loss RG-8/U coax was installed between the transceiver and amplifier. This was used for the first couple of weeks because the cable was in the junk box but the loss is a little worse than Belden 9913 so it was subsequently replaced with EcoFlex 10 Plus. If you're buying new, just buy the EcoFlex ($1.19/foot from Universal Radio). A similar length of 4-wire rotator cable connects the rotor control box in the shack to the rotor.


A few words on connectivity: The IC-706MkIIG uses a UHF output connector and the TE Systems amplifier uses UHF input and output connectors, while the antenna uses a Type N connector. As you will note from the photographs I use a short UHF to N coax "stub" on the transceiver output and also on the amplifier input and output to make connecting and disconnecting the equipment easier (in the transceiver case for switchover to my terrestrial 144 antenna, and in the amplifier case to speed up the connect/disconnect time of the portable "amplifier box"). Because of this the transmission lines from the shack to the amplifier and from amplifier to antenna use Type N connectors. These cost approximately $10 each for Type N connectors to fit the EcoFlex 10 Plus cable. Type N connectors are also waterproof, a big plus when it's raining while I'm operating EME with the amplifier box outside.

Thanks to already having a suitable amplifier/preamp, a Rigblaster and low-loss coax, I spent

$500 to get on 144 MHz digital EME. Almost half of that amount was in the antenna and the balance was in the second power supply (for powering the amplifier outside), the rotor, and a few miscellaneous items.

The photos that follow illustrate how my initial 144 MHz EME station is configured. Captions on each photo explain the set-up and suggest what is necessary to duplicate the configurations shown.

M2 2M9SSB Yagi on wood tripod with TV rotor and

homebrew manual adjustable-elevation mounting.

The main station layout at K4MSG showing the HF and VHF/UHF equipment and laptop computer, *minus* the 144 MHz amplifier (which usually sits on the top shelf next to the 432 MHz amplifier).

Close-up of the IC-706MkIIG transceiver and MFJ 25-amp switching power supply.

Rotor control units. The left-most unit (facing right) is the azimuth control for the single EME Yagi the rear control (facing front) is for the roof-mounted 144 and 432 MHz terrestrial Yagi antennas.

The Type N interface to the IC-706. The left (short) cable comes from the transceiver and the right cable goes to the external EME antenna location. This arrangement allows the EME cable to be disconnected and the cable to the terrestrial antenna(s) connected while avoiding the use of a switch or relay.

The outdoor amplifier housing showing the MFJ 30-amp switching power supply (lower), 144 MHz amplifier/preamp and homemade shelf next to the housing. Note the amplifier cooling fan mounted on the front of the housing.

The amplifier housing with power supply and amplifier/preamp installed and running. The housing is a plastic storage box available at Walmart for around $6 with suitable holes drilled for fan mounting and cable access. It has a convenient carrying handle on the removable top cover.

Rear view of the amplifier housing note the access holes for RF and power cables. The row of four holes allows airflow across the amplifier cooling fins (the fan draws air in through these holes and blows outward).

Also note the two coax stubs on the amplifier input & output connectors these simplify connection of the coax lines from the transceiver & EME antenna. Since the amplifier input & output connectors are UHF and not waterproof while the Type N connectors on the outer ends are waterproof if properly installed, this arrangement ensures dry RF connections despite being quick to connect/disconnect.

A plastic basin inverted over the amplifier housing protects it from both rain and direct sunlight and keeps the AC power connection to the extension cord dry (it's laying on top of the housing under the basin). The basin also overhangs the rear of the housing and protects the access holes for cables and airflow ingress.

In Part III we'll take a look at actual EME operation using JT65b.

Moonbounce for the Rest of Us

PART III - FIRST STEPS IN 144 MHz EME OPERATION

SETTING UP THE SOFTWARE

If you've never used WSJT software you will need to download it from the Internet and then READ THE MANUAL to familiarize yourself with the screens. You'll also need to enter your own station parameters into the WSJT program and make sure that the necessary interfaces (serial connection, audio in, audio out, etc.) between the laptop/PC, Rigblaster, and transceiver are correct and functioning as they should. Verify that the Dimension 4 or other "time sync" software is keeping the PC clock corrected to less than a second of error. There are instructions on setting the level of the audio tones that comprise the digital signal fed to the transceiver follow these instructions carefully, especially the procedures for balancing the tone levels *AND* ensuring that no ALC action takes place as this can distort the transmitted signal and make decoding difficult or impossible at the receiving station.

Since the WSJT manual is rather long and - not to put too fine a point on it - a bit ponderous, I highly recommend that you also download "W7JG's Additional Tips for Using JT65 in WSJT" which you can find at http://www.bigskyspaces.com/w7gj/JT65.pdf . Here you will find clear and concise instructions for how to set the parameters in the JT65 screen for most efficient EME operation.

Initially, you should plan to operate only at Moonrise, especially if you have no elevation control on the antenna. You can go to the "timeanddate.com" website at

to print a list of the Moonrise times and azimuths for our area (Washington, DC) for the current month. Make sure you choose the "rise/set time/azimuth" display option. The times shown in the table are local time corrected for DST.

OPERATING AND COMPLETING CONTACTS

Begin your first EME operation by pointing the antenna at the necessary azimuth point specified for Moonrise. WSJT should be set up for 144 MHz and JT65b mode. I usually turn on the transceiver and laptop about an hour before scheduled Moonrise, bring up the WSJT screens, and check that Dimension 4 is controlling time correctly.

Dimension 4 requires that the PC be connected to the Internet continuously to keep the system time accurate.

At this point I carry the amp/preamp and small power supply outside (in the special container shown in the photos of the previous section), make the connections from the shack and to the antenna, and power up the equipment. Then I return to the shack and run a couple of test sequences to check levels on the transceiver, etc. I also walk outside during the "send" portions to make sure that the red transmit LED is glowing on the front of the amplifier and that the power supply meter indicates correct current draw (about 23 amps in my particular case).

Just before the Moon is scheduled to break the horizon I bring up the N0UK JT65 EME-1 chat page (It doesn't hurt to also check the JT65 EME-2 page just to see which is being currently used) and look to see who may be active, who is calling CQ, etc. Once the Moon rises above the horizon, tune the transceiver to where stations are calling CQ and see if you get any decodes by clicking the MONITOR button on WSJT. Make sure to set your RIT to the "Doppler" offset indicated on the WSJT screen.


If you decode a CQ click the "AUTO ON" button on WSJT but first MAKE SURE that you are transmitting the OPPOSITE time period from the CQing station, i.e., if he's sending "1 st " you should be sending "2 nd " and vice-versa. If you decide to try a CQ yourself make sure you alert the users on the chat page by posting something like " CQ 144.120 2nd K4MSG Paul FM19".

Here is how the correct sequences look for a VALID QSO for two scenarios: Answering a CQ, and someone else answering your CQ.


Freedom v. Regulation

Since the days of the early automobile, there has been a debate about the freedom versus regulation in regards to speed limits. Some states, such as Montana and Nevada, have historically opposed restrictive speed limit laws and imposed minimal fines for noncompliance.

In 1995, the U.S. Congress handed speed limit laws back over to the individual states and allowed each state to decide its maximum speed to drive. Since then, 35 states increased their limits to 70 mph or higher.


15 fastest 40 times in NFL history

Oct 3, 2013 Cleveland, OH, USA NFL Network announcer Deion Sanders prior to the game between the Buffalo Bills and Cleveland Browns at FirstEnergy Stadium. Mandatory Credit: Andrew Weber-USA TODAY Sports

The 40-yard dash is the most watched and most talked about event annually at the NFL scouting combine.

Every February, the NFL Scouting Combine rolls around and give us one last taste of football before basketball, baseball and golf take over our televisions until the NFL Draft. Stars are born, discovered, substantiated and criticized by NFL scouts as we all watch, hoping to get a glimpse or idea of what tomorrow’s NFL will look like.

Capturing our attention more than any event at the combine is the 40-yard dash.

In America, we love everything fast — from cars to the internet. We don’t make exceptions for our athletes. Speed fascinates our sports-viewing society, likely because most of us just don’t have it. Be that as it may, we know what it can do and how it can potentially help our favorite teams going forward, arguably more so than any other measurable.

We’ve seen some blazing 40 times roll across our screens at the combine over the years. Many of the players who ran them went on to long, successful NFL careers. Some of them never panned out and vanished from the NFL scene almost as fast as they ran the 40.

Prior to the 1999 combine, 40 times were clocked by a human-operated stop watch, as opposed to the electronic system in place now. As a result, many of those pre-1999 times have been scrutinized and doubted.

However, we have still included the pre-electronicly recorded times for the purpose of discussion.

The times listed are the official times, not the one-off times certain players ran that did not end up being deemed “official.”

Dec 15, 2013 Atlanta, GA, USA Washington Redskins quarterback Kirk Cousins (12) celebrates a touchdown with wide receiver Santana Moss (89) in the second half against the Atlanta Falcons at the Georgia Dome. The Falcons won 27-26. Mandatory Credit: Daniel Shirey-USA TODAY Sports

Back in 2008, Orlando Scandrick (Boise State) became the most recent player to log a 4.32 at the combine. Scandrick was taken by the Cowboys in the 5th round of the NFL Draft that year and has been in Dallas ever since. He has logged seven interceptions during his career.

Several players have posted a time of 4.31 since 2000 including Jonathan Joseph (South Carolina) in 2006, Tyvon Branch (Syracuse) and Justin King (Penn State) in 2008, Aaron Lockett (Kansas State) in 2002 and Santana Moss (Miami) in 2001. Perhaps the most famous player to post a 4.31 at the combine recently was Arizona Cardinals All-Pro corner Patrick Peterson.

Joseph has gone on to become one of the better corners in the NFL, while Santana Moss has enjoyed a respectable 14-year career with the Jets and Redskins. He has eclipsed to 1,000-yard mark four times and caught 66 touchdowns.

Lockett finished his playing days in the CFL in 2006. Branch is still a safety for the Oakland Raiders and King last played for the Steelers in 2013.

Oct 20, 2013 Indianapolis, IN, USA Indianapolis Colts wide receiver Darrius Heyward-Bey (81) during the game against the Denver Broncos at Lucas Oil Stadium. Mandatory Credit: Brian Spurlock-USA TODAY Sports

“That guy has 4.3 speed.” We’ve all heard that before. It’s the unwritten standard for elite speed.

The most recent player to post an exact 4.3 at the combine was Darrius Heyward-Bey (Maryland) in 2009. The late Al Davis shocked the football world when he drafted Heyward-Bey with the 7th overall pick that year — based on what appeared to be speed alone.

It’s safe to say Heyward-Bey has been less than average during his NFL career. He never really became what Davis envisioned in Oakland. He spent 2013 in Indianapolis and 2014 in Pittsburgh, where he caught three passes.

The most recognizable names among the players to post a 4.29 are Trindon Holliday (Louisiana State) in 2010 and Dominique Rodgers-Cromartie (Tennessee State) in 2008.

Holliday, a return specialist, has bounced around five different rosters since being drafted by the Texans in 2010. His best work came with the Broncos from 2012-2013. Despite the title of the video above, Holliday’s final official time at the 2010 combine was 4.29.

Rodgers-Cromartie has become somewhat of a journeyman corner, playing for four teams so far during his seven-year career. He was elected to the Pro Bowl in 2009.

Others to clock 4.29 are Fabian Washington (Nebraska) in 2005, Lavernanues Coles (Florida State) in 2000, James Williams (Fresno State) in 1990, Gaston Green (UCLA) in 1988 and Jay Hinton (Morgan State) in 1999.

Four players have clocked an official 4.28 at the combine: Champ Bailey (Georgia) in 1999, Jacoby Ford (Clemson) in 2010, Raghib “Rocket” Ismail (Notre Dame) in 1991 and Kevin Williams (Miami) in 1993.

Bailey, as we all know, has gone on to have a Hall of Fame-caliber career, establishing himself as one of the better cornerbacks in recent NFL history.

Jacoby Ford spent his first three seasons in Oakland and has bounced from the Jets to the Titans in the last two years.

“Rocket” Ismail became a household name during his time at Notre Dame, eventually spurning the NFL for the CFL where he won a Grey Cup in 1991. He eventually signed with the Raiders in 1993 and had a fairly pedestrian NFL career.

Williams is best remembered for his time with the Dallas Cowboys where he replaced Alvin Harper in 1995 as the No. 2 receiver opposite Michael Irvin. He would go on to play for the Cardinals, Bills and 49ers before finishing his career in 2000.

Five players over the years have run a 4.27 at the combine: Marquise Goodwin (Texas) in 2013, Stanford Routt (Houston) in 2005, Devin Hester (Miami) in 2006, Darren McFadden (Arkansas) in 2008 and James Jett (West Virginia) in 1993.

Goodwin has had some success as a return specialist and receiver for the Bills early in his career.

Routt enjoyed a long career, spending most of it with the Raiders and later joining the Chiefs and Texans.

Devin Hester has gone on to become the greatest kick returner in NFL history, making his mark with the Bears before joining the Falcons in 2014.

McFadden has had an injury-riddled and overall disappointing career with the Oakland Raiders. He has never been able to replicate the success he had in college.

James Jett played ten seasons with the Raiders, mostly as the No. 2 to Tim Brown. He was a member of the gold medal-winning 4 x 100 relay team for the United States at the 1992 Olympic games in Barcelona.

Two players have posted a 4.26 at the combine: Dri Archer (Kent State) in 2014 and Jerome Mathis (Hampton) in 2005.

Dri Archer saw limited action for the Steelers during his rookie season. The rookie running back logged ten carries for 40 yards and caught seven passes for 23 yards.

Mathis began his career on a high note for the Houston Texans. He was voted into the Pro Bowl as a rookie kick returner in 2005. That same season, he won the NFL Alumni Special Teams player of the year award.

After two more seasons with Houston, Mathis joined the Redskins in 2008. That would be his final season in the NFL, as he would spend the next three years in the CFL, UFL and the Arena Football league before leaving football altogether in 2011.

Sep 19, 2013 Philadelphia, PA, USA Philadelphia Eagles quarterback Michael Vick (7) is chased by Kansas City Chiefs linebacker Justin Houston (50) during the fourth quarter at Lincoln Financial Field. The Chiefs defeated the Eagles 26-16. Mandatory Credit: Howard Smith-USA TODAY Sports

Two pretty familiar names posted 40 times of 4.25: Randy Moss (Marshall) in 1998 and Michael Vick (Virginia Tech) in 2001.

By most accounts, Moss will go down in history as the second best receiver ever to play the game — behind only Jerry Rice. He brought a rare combination of size, speed and great hands that few had ever seen before. The end result was a nearly unstoppable force through the prime of his career.

Speaking of things few had seen before, Vick’s 40 time is the fastest we’ve ever seen from a quarterback. He was electric during his first few seasons as a result of his speed and his underrated big arm. Because of his legal issues in the prime of his career, we’ll never really know how good he could have been.

Two players have posted a 4.24 at the combine: Chris Johnson (East Carolina) in 2008 and Rondel Menendez (Eastern Kentucky) in 1999.

Johnson’s time is the fastest recorded since the combine began using the electronic timing system. During his first six seasons in the NFL with the Tennessee Titans, Johnson ran for over 1,000 yards each year. The 2014 season as a member of the New York Jets was Johnson’s first sub-1,000 yard campaign.

Rondel Menendez got himself drafted with his blazing time. The Falcons took him in the seventh round of the 1999 draft. Be that as it may, Menendez never played a single regular season down in his career.

Almost as if on purpose, Deion Sanders (Florida State) turned in a 40 time in 1989 where the numbers behind the decimal matched his jersey. Sanders is widely regarded as the best cover corner in the history of the game and one of the faster players ever as well.

The other guy to run a 4.21 was Don Beebe (Chadron State) in 1989. Beebe was one of the most dependable slot receivers in history, doing his best work with the Buffalo Bills from 1989 t0 1994. He appeared in six Super Bowls with two teams — Buffalo and the Green Bay Packers.

Jan 10, 2015 Arlington, TX, USA ESPN reporter Joey Galloway during Media day at Dallas Convention Center. Mandatory Credit: Matthew Emmons-USA TODAY Sports

Joey Galloway (Ohio State) ripped off a blazing 4.18 back in 1995. The Ohio native played 16 seasons in the NFL for five different franchises. His speed made him a dangerous deep-threat during his tenure in the league. He finished with 77 touchdown catches and 15.6 yards per reception over the course of his career.

Apparently, he can still fly.

Former Ohio State quarterback and ESPN analyst Kirk Herbstreit tweeted out in July of 2014 that Galloway posted a 4.29 on grass at the age of 42.

Ahman Green (Nebraska) posted a 4.17 back in 1998. Green played 11 seasons for three different NFL franchises.

The four-time Pro Bowler is in the Green Bay Packers Hall of Fame and is the all-time rushing leader in Packer history.

Darrell Green (Texas A&M-Kingsville) ran a 4.15 back in 1983. Green spent his entire 20-year career with the Redskins where he was known for most of it as the NFL’s fastest man.

Green was selected to seven Pro Bowls, played in three Super Bowl — winning two — and was the 1996 Walter Payton Man of the Year.

In 1990, Alexander Wright (Auburn) clocked a 4.14 at the combine. The Dallas Cowboys selected the in the second round of the NFL Draft that year. He played a total of seven seasons for three teams: the Cowboys, Raiders and Rams.

The 40 time to rule them all — the legendary 4.12 put up by Bo Jackson (Auburn) in 1986. Though it has been questioned because of the human element involved, it’s not hard to imagine Jackson running a 4.12 40 if you’ve ever seen him play or even seen highlights.

NFL fans would have to wait a year to see Bo on the gridiron, as he was pursuing a professional baseball career with the Kansas City Royals that put his pro football debut on hold.

Bo spent his entire NFL career with the Raiders, which should not come as a surprise. The Raiders have always been known to value speed over pretty much everything else. In fact, of the 36 players mentioned in this article, exactly one-third of them spent time with the Raiders during their careers.


Speed AM-116 - History

Flightradar24 is a global flight tracking service that provides you with real-time information about thousands of aircraft around the world. Flightradar24 tracks 180,000+ flights, from 1,200+ airlines, flying to or from 4,000+ airports around the world in real time. Our service is currently available online and for your iOS or Android device.

By using this site, you agree to the use of cookies. Please see our Privacy Policy for more information including a full list of cookies used.

  • We use third-party cookies for analytics tracking. We use data gathered from tracking to understand user behavior and to help us improve the website.
  • We use our own cookies to store session and settings data.
  • We use third-party cookies for presenting ads.

The main change includes: an update of data processors used by Flightradar24 to support our product and service.

We encourage you to read these in full. If you have any queries please feel free to contact us. By continuing to use Flightradar24.com, you agree to our Terms of Service and Privacy Policy.


An Accelerated History of Internet Speed (Infographic)

The story of the internet so far has been one of both ever-faster speeds and ever-higher demand for connectivity. According to Cisco, worldwide internet traffic reached more than 20 exabytes per month in 2010. (An exabyte is a billion gigabytes.) The smart money says demand is only going to keep rising.

Fortunately, the physical infrastructure of the internet is equipped to handle it, at least for a while. The undersea cables we use now can be upgraded to move data at 100 gigabytes per second, about 10 times faster than current speeds. And a $1.5 billion project is underway to reduce the lag time of signals between London and Tokyo by 60 milliseconds using a fiberoptic cable in the Arctic Ocean, the first of its kind in that part of the world.

The infographic below, compiled by Gator Crossing, a Houston-based web hosting service provider founded in 2002, provides a history of the internet along with some facts even dedicated web geeks might not know. Such as the fact that as of 2010, about half of rural households in America did not have internet access at home. Where's Google Fiber when you need it?

Click to Enlarge+

Entrepreneurs require more than just money, which is why we aim to empower you, as well as act as a catalyst for value creation.

Book Sale - Save 60%!

Through 6/20/21, save on our collection of recommended side hustle and Start Your Own books, including:


1990 Maserati 2.24V (man. 5) detailed performance review, speed vs rpm and accelerations chart

How fast is this car ? What top speed ? How much fuel ? - Performance Data

Maserati 2.24V (man. 5 speed)
as offered for the year 1990 for Europe

Car power to weight ratio net:

138.5 watt/kg / 62.8 watt/lb

Car weight to power ratio net:

7.2 kg/kW / 5.3 kg/PS / 11.9 lbs/hp

Production/sales period of cars with this particular specs:

mid-year 1988 - mid-year 1991

spark-ignition 4-stroke

180 kW / 245 PS / 241 hp (DIN)

9.3 / 12.2 / 15.4 (12.3) l/100km

30.4 / 23.2 / 18.3 (23) mpg (imp.)

25.3 / 19.3 / 15.3 (19.2) mpg (U.S.)

U.S. EPA city/highway (combined):

U.S. EPA (after 2008) city/highway:

© automobile-catalog.com ProfessCars&trade simulation
(for the car with basic curb weight, full fuel tank and 90 kg (200 lbs) load)

(theor. without speed governor)

Acceleration on gears:

60-100 km/h on IVth gear (sec)

(or top gear if total number of gears 6.4

80-120 km/h on IVth gear (sec)

(or top gear if total number of gears 6.4

80-120 km/h on Vth gear (sec):

80-120 km/h on VIth gear (sec):

40-60 mph on IVth gear (sec)

(or top gear if total number of gears 5.1

50-70 mph on IVth gear (sec)

(or top gear if total number of gears 5.1

50-70 mph on VIth gear (sec):

60-100 km/h through gears (sec):

80-120 km/h through gears (sec):

100-180 km/h through gears (sec):

40-70 mph through gears (sec):

50-90 mph through gears (sec):

simulation based on the European type of traffic

extra-urban / city / highway / average combined:

8.7-10.4 / 15.5-18.6 / 10.3-12.4 / 12.3

27-32.5 / 15.2-18.2 / 22.8-27.4 / 22.9

22.5-27 / 12.6-15.2 / 19-22.8 / 19.1

9.6-11.5 / 5.4-6.5 / 8.1-9.7 / 8.1

If you refer to the information from this website, please always indicate www.automobile-catalog.com as a source, with the appropriate link.

To view table with complete technical specifications (including final drive and gear ratios, powertrain description, dimensions etc.) and more photo, or to compare up to 5 cars side-by-side - click one of the the buttons below:


AM radio ranges from 535 to 1705 kilohertz, whereas FM radio ranges in a higher spectrum from 88 to 108 megahertz. For AM radio, stations are possible every 10 kHz and FM stations are possible every 200 kHz.

The advantages of AM radio are that it is relatively easy to detect with simple equipment, even if the signal is not very strong. The other advantage is that it has a narrower bandwidth than FM, and wider coverage compared with FM radio. The major disadvantage of AM is that the signal is affected by electrical storms and other radio frequency interference. Also, although the radio transmitters can transmit sound waves of frequency up to 15 kHz, most receivers are able to reproduce frequencies only up to 5kHz or less. Wideband FM was invented to specifically overcome the interference disadvantage of AM radio.

A distinct advantage that FM has over AM is that FM radio has better sound quality than AM radio. The disadvantage of FM signal is that it is more local and cannot be transmitted over long distance. Thus, it may take more FM radio stations to cover a large area. Moreover, the presence of tall buildings or land masses may limit the coverage and quality of FM. Thirdly, FM requires a fairly more complicated receiver and transmitter than an AM signal does.


Testing the waters of intimacy

As Speed’s marriage approached, Lincoln projected his own confused fantasies onto his friend to vicariously test the waters of intimacy. (Lincoln and Mary Todd, at that point, weren’t in contact.)

It seems Speed barely tumbled out of his wedding bed on the morning of Feb. 16 to write his friend of his successful consummation – and how the roof didn’t fall in – which elicited a fervid response from Lincoln:

“I received yours of the 12th written the day you went down to William’s place, some days since but delayed answering it, till I should receive the promised one, of the 16th, which came last night. I opened that latter, with intense anxiety and trepidation – so much, that although it turned out better than I expected, I have hardly yet, at the distance of ten hours, become calm.”

It’s remarkable to think that the 33-year-old Abraham Lincoln was still feeling anxious a full 10 hours after reading the news of Speed’s successful wedding. Was this an emotional turning point for Lincoln? It’s as if his fears of intimacy were suddenly allayed: If Joshua could do it, so could he. Within a few months, he resumed his courtship of Mary Todd, who had graciously waited for him. They married on Nov. 4, 1842, in the parlor of the Edwards’ home.

Some 10 days later, Lincoln ended an otherwise innocuous letter to a business partner, Samuel D. Marshall, by noting, “Nothing new here, except my marrying, which to me is a matter of profound wonder.” Lincoln would remain often sad and melancholy, but he was never again clinically depressed and suicidal. His friendship with Speed proved therapeutic, even redemptive.

Joshua Speed certainly helped guide him emotionally toward intimacy and love. As one old friend put it, Lincoln “allways thanked Josh for his Mary.”


This article was originally published on The Conversation. Read the original article.

Charles B. Strozier Professor of History, City University of New York.


Watch the video: You Might Think BLUE LIGHTNING MCQUEEN (June 2022).


Comments:

  1. Kigasar

    It can not be!

  2. Guiseppe

    This theme is simply matchless :), it is very interesting to me)))

  3. Mukora

    Artifice

  4. Anderson

    What rare luck! What happiness!

  5. Ramon

    The sympathetic phrase



Write a message