Grimsby Beam Station/GBI

Type: PTT (P)
Circuit: CKT#302


Transmitter station: Tetney
Receiver station: Skegness, Winthorpe
Operational office: London
Receiver end station: Dhond, 50 miles E of Poona
Transmitter end station: Kirkee/VWZ, 75 miles SE of Poona
Operational office: Poona

Callsign GBI was dedicated callsign for radiocommunication with India and South Africa.


2 waves were in use: 35 and 16 m (rounded to full kHz) :

35m - NIGHT
8771 kHz
8773 kHz
8780 kHz
8787 kHz
8789 kHz

16m - DAY
18491 kHz
18493 kHz
18500 kHz
18507 kHz
18509 kHz

Similiary like GBH 5 channels multiplex transmitter was in operation.
At that time that what we know as maritime radiotelephone band on 8.7 Mhz was very popular fixed service band.
Althought in my sources 19m was refered as 2 highest freqs I think it was exactly the same as 35m wave.


Since there is night and day band it is easy to guess how they operated:

16m    0000-1200
35m    1200-0000

Working skeds:

1130-1730     DAY FREQ         telecom_opchat_dx() at zero freq.
2330-0530     NIGHT FREQ     telecom_opchat_dx() at zero freq.

side channels:

00-50 min   High Speed Morse at 150 WPM
50-00 min   V tape is sent


[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
[5] Przedląd Radjotechniczny 9-10