Showing posts with label Radio. Show all posts
Showing posts with label Radio. Show all posts

Tuesday, October 16, 2018

Radio

I have decided to add a new label that is searchable. I have several posts that are about radio and radio topics. I recently received an email from a young lady that was interested in ham radio and had discovered my orphan blog about ham radio. She suggested adding the following link about ham radio emergency communications.

https://alertfind.com/amateur-radio-and-emergency-communications/

Thank you Ella, that was very timely given the recent hurricane and the response by the ham radio community. Hams are currently deployed throughout the Florida Panhandle at shelters and emergency operations centers. Communications is both on linked UHF repeaters (sarnetfl.com) and on HF on 40 and 80 meters depending on propagation.

 
Here are the contents of the orphaned blog:

Tuesday, August 9, 2016

Radio Telegraph

After I did the Railroad Telegraphy post I thought I would mention another type of key and keyers. The electronic fully automatic keyer that uses "paddles". Instead of just two wires with bugs and straight keys, paddles have three wires, one for dit, another for dah and ground. They go the keyer. Close the contact between the dit wire and ground and they keyer generates dits for as long as the connection is made. Dahs are generated the same way, continuity between the dah wire and ground. To my knowledge, these keyers were never used with the railroad.

What happens if you close both contacts at the same time? Glad you asked. From Wikipedia:
"Iambic keying or squeeze keying creates alternating dits and dahs. This makes sending some characters easier, like the letter C, by merely squeezing the two paddles together. In single-paddle, non-iambic keying, the hand motion would require alternating four times for C (dah-dit-dah-dit).
Iambic keyers function in one of at least two major modes: Mode A and Mode B."

See the wiki article for the differences in modes. 

My newer ham radios have keyers built in.

Photos of my iambic paddles:

MFJ-564 similar to Bencher BY-1/2



Brown Bros Model BTL-A

dit dit

Thursday, August 4, 2016

Railroad Telegraphy

Something a little different, no train photographs. For the hardcore, there are some pics in the links. :)

The first ever railroad telegraph message was send and received in Orange County, NY in January, 1851.

Samuel Morse invented his telegraphic code in 1832. Originally magnets were used to mark the dits and dahs on paper tape with ink. The telegraphers discovered they could decode the letters by the sound made by the machine, later to be called the sounder.

Sounder with resonator. Note the tobacco tin to give it a distinctive sound.

The first ever railroad telegraph message was send and received in Orange County, NY in January, 1851. There is an interesting website with a nice telegraph page here.

In addition to the sounder the telegraph key was essential. There are numerous styles but basically there are two kinds. The manual "straight key" and the semi automatic key or bug. Descriptions follow.

This is called a straight key. It is a Speed-X model J-38. J-38 is the military designation from WW II.  Note the shorting lever, required for land line keys. No one mentions that the shorting lever was also required for some older ham radios that used cathode keying. It was closed when you wanted to use voice.


Next is the Vibroplex "bug". It is a semi automatic telegraph key which automatically sends "dits" but the "dahs" must be made individually. Vibroplex was founded in 1905 by Horace Martin and the basic design has remained unchanged.

I am also an amateur radio operator (ham). My straight key is pictured above.  Here is my Vibroplex Original Standard. It is not very old, the serial no. is 108708.


Close up of the nameplate and "dit" contacts. 


There are several versions of Morse code but the two that are important for this post. American and international Morse

American Morse Code — also known as Railroad Morse—is the latter-day name for the original version of the Morse Code developed in the mid-1840s, by Samuel Morse and Alfred Vail for their electric telegraph. The "American" qualifier was added because, after most of the rest of the world adopted "International Morse Code," the companies that continued to use the original Morse Code were mainly located in the United States. American Morse is now nearly extinct—it is most frequently seen in American railroad museums — and "Morse Code" today virtually always means the International Morse which supplanted American Morse.

 Another excellent article with some great photos found here.

Ever wonder what all the wires on the poles that used to be next to the tracks were for?
- Carried telegraph communication, both railroad and public
- Dispatcher's voice communication
- Teletype communication
- Electrical power to run signals, switch machines, wayside detectors
- Wayside detector communication
- Vital signal information
Some of the lines were leased to companies like Western Union.
It has all been replaced by radio, satellite and buried cable / fiber.

EDIT: An article by Jim Thompson, a retired Frisco telegrapher. Long but really interesting. Some history plus personal experiences.(Moved here from my comment below)


Monday, July 11, 2016

Communications and Signals:Then and Now



Lots of interesting information and some great video from Norfolk Southern Corp.



Love the NS logo.
EMD F-9A

Two units still active.  More here.


Friday, March 11, 2016

Defect Detectors Rev. 3/20/16

A defect detector is a device used on railroads to detect axle and signal problems in passing trains. The detectors are normally integrated into the tracks and often include sensors to detect several different kinds of problems that could occur. Defect detectors were one invention which enabled American railroads to eliminate the caboose at the rear of the train, as well as various station agents stationed along the route to detect unsafe conditions. The use of defect detectors has since spread to other overseas railroads.


Defect Detector with Audio



The photos are of the defect detector on the FEC mainline in S. Lucie County, Fl. at Walton Road, north of Jensen beach.

The audio was recorded online listening to the Broadcastify Folkston, Ga. area feed. The detector is on the dual CSX mainline mile A610.6 between Boulogne and Callahan, Fl. Listen to the end.

More information at the Trains Magazine website. Always a good source.
Several other videos on YouTube. 

EDIT March 20, 2016 to add  some still photos

Hotbox or Hot Bearing Detector


Dragging Equipment Detector

Laser Detector
Lasers shine down on each side of the passing train. Anything that cuts through the beam will be counted as a defect.

Control box and VHF Antenna

Overview of hotbox and dragging equipment detectors with one leg of bridge that holds laser detectors.