| MARITIME RADIO STATIONS OF THE WORLD
Portishead
|
|
| Portishead Radio Callsign | Frequency | Amateur Frequency +or- 5 kHz |
| GKB2 | 4274 | 3525 |
| GKB4 | 8559.5 | 7025 |
| GKB5 | 12835.4 | 14050 |
| GKB6 | 17113 | 18075 |
| GKB7 | 22448.7 | 21050 |


On the 30th April 2000 hourly broadcast announcements gave details of the station's final broadcast times.
In the final hour a "private" message was heard being broadcast by one of the station's "old timers". The message read:-
CQ de GKB =
This message is from an R/O who has been working into and from GKB since 1963
= krs and 73s
= John Hocking +
In the run-up to the station's final RadioTelephony broadcast the station's frequencies were once again being marked by an elderly Post Office "circuit adjustment" recording specially resurrected to mark the occasion, something which brought back memories of yesteryear to many Radio Officers and Post Office Radio Engineers:-
"This is a transmission from the Portishead Terminal of the Ship's Radio Telephone Service of the British Post Office.
This transmission is for circuit adjustment purposes. No acknowledgement of this transmission is required, except by users of the service, at this time."
The final radiotelephony broadcast was made at 1200 GMT, first on 4383, 8764 and 12346kHz and then on 17245, 19755 and 22711khz.
The final RTT broadcast transmitted automatically as 1201z and carried a message identical to that read on radiotelephony and sent on CW.
Finally, the sequence of close-down events finished with a hand-keyed message broadcast on CW on the stations GKB range of transmitters.
The message read:-
"CQ CQ CQ de GKB2/4/5/6 =
This is the last broadcast from Portishead Radio. For 81 years we have served the maritime community. We say thankyou to all those who have supported and used our station.
We pay tribute to Marconi who made it all possible. His first transmissions across water were made from nearby here and so started the radio era. We are proud to have been part of that era.
As this historic time in the commercial messaging world comes to a close the manager and radio officers wish you farewell from Portishead Radio/GKB + SK
The signal SK indicates end of sending - in the Amateur Radio world it also stands for Silent Key., used when a Radio Amateur dies, never to be heard on air again.