RED ARMY RADIOTELEGRAPH SIMULATOR
Grimsby Beam Station/GBH
Type: PTT (P)
Circuit: CKT#301
OVERVIEW:
Transmitter station: Grimsby
Receiver station: Skegness, Winthorpe
Operational office: London
Receiver end station: Rockbank, near Sydenham, near Melbourne
Transmitter end station: Ballan/VIZ (50 miles NW of Melbourne)
Operational end office: Sydney
Callsign GBH was dedicated callsign for communication with Australia only.
FREQ:
It seems 5 channels were in use (rounded to full kHz) :
11571 kHz
11573 kHz
11580 kHz
11587 kHz
11589 kHz
Analysing these freqs it is obvious it was AM transmitter at 11580 kHz modulated with +/- 9 kHz signals and 5 working channels were created.
Multiplex was new method at that time and is used even today.
Typically one channel was reserved for service communication, but probably it was one side communication in diferent time windows.
On other channels High Speed Morse (AUTO) at speed 150 WPM was used. If really such speed was used, it means that link quality was very good.
Probably diversity receiving system was used on the receiving end, what is good measure to ensure high signal to noise ratio, plus dedicated antennae
make it really powerfull system.
SIMULATION:
It was for sure difficult link because both stations are almost at its antipodes.
As some sources claims operational period was short and transmitting station worked at it local night (day on other antipode).
Thus, there was probably no direct communication on this link, but instead they were exercised technique of twicely transmitting the same tape in case of
inteferrence or ZSU. No opchat is simulated, just AUTO and calling tapes. Station is on the air whole operational period.
Working sked:
1900-0500 operational period
00-50 min High Speed Morse at 150 WPM
50-00 min V tape is sent
SOURCES:
[1] Commercial Short Wave Wireless Communications, part 1, Marconi Review 1929-10
[2] Commercial Short Wave Wireless Communications, part 2, Marconi Review 1929-11
[3] The History of Shortwave Radio in Australia
[4] tetneybeamstation.blogspot.com
[5] Przedląd Radjotechniczny 9-10
Return