Radio in the field

[RobertBr]

The IET have updated their article  First World War Communications and tele net things which may be of interest.

Bob

[Moonraker]

I clicked on Bob's link and got this message:

Your link may be a few hours old. Click the link below to continue to the page you selected, or return to search.yahoo.com to search again for the most recent results.

https://eandt.theiet.org/2014/06/16/ww1-first-world-war-communications-and-tele-net-things

which took me to an interesting website. Thanks.

[Moonraker]

13 hours ago, KizmeRD said:

I was just searching Internet Archive and came across this…

The Cavalry Journal Volume 19 1929

https://archive.org/details/cavalry-journal-1929-vol19/page/548/mode/1up?q=marconi+pack

The regular cavalry brigades exercising on Salisbury Plain in 1910 made use of a limber wagon wireless set with a stated range of 50 miles, whereas ‘a Yeomanry Regiment’ had a lighter pack set which was said to have a range of 15 miles.

MB

Edit - Westmorland and Cumberland Yeomanry!

 

Very useful link, thanks.

[Chasemuseum]

On 29/02/2024 at 22:46, Moonraker said:

What would have been the range of the 1910 sets?

The 1910 and 1913 pack sets appear to be very similar but this was a period of rapid advances in radio/wireless technology.

Marconi company focus was on maritime applications and the 500W pack set was based on their small model maritime wireless unit.

The 1913 unit was a 500W spark transmitter, powered by a stationary version of the Douglas Motor Cycle Company 2 3/4 horse power 2-cylinder petrol engine, configured to run a 150V generator that powered the transformer and capacitors (Leydon Jars) in the lower box of the wireless station with a high voltage lead back to the Synchronous spark generator on the back of the generator shaft. with another HV lead back to the wireless set. This ultimately powered a horizontal end fed dipole antenna on two 30ft masts 400 ft apart.   The transmission frequencies were 550 / 650 / 750 metres. (545 kHz, 461 kHz & 400 kHz)

Did the 1910 model use a Synchronous spark ? Don't know. Not sure which year this technology was invented by Marconi. It was in service in 1912, but not sure about 1910.

The 1913 model had a nominal range of 30 miles. This was line of sight transmission in 360 degrees. In practice, at night with reflection off the ionosphere these units were recorded as achieving 600 miles. 

You have to remember that these were very crude transmitters, very inefficient. Lots of energy with very poor quality tuning. Add to this, that the receivers at this time were crystal receivers without amplifiers, so they could only pick up a relatively strong signal. Then add to this, that there were very few wireless transmissions occurring so that the atmosphere was not the crowded space it is today.  

The 1913 pack set stayed in use through all of WW1, mainly in theatres other than the Western Front. Palestine, East Africa and Mesopotamia in particular. By the end of the war there were a number of modifications improving the sets, in particular the use of a 3-valve amplifier box with the receiver. The day time range was probably dramatically improved.  .

Without having actual information on the 1910 model, it's performance was probably very similar to the 1913, but probably not as easy to operate or as reliable.