Radio Caroline kiittää

Aloittaja KKX, 04.12.2021 - 10:39

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Friday 3rd December: Transmitter engineer Alan Beech reports

A big thank you from everyone here at Radio Caroline to all those who have sent in reception reports over the past week via our website and other means for our improved 648 AM service.

To say that we have been rather overwhelmed and inundated would be an understatement! With just a few exceptions all feedback is that we have a healthy increase in signal and audibility. That was the main aim of our power increase – to improve the signal in our primary coverage areas of Essex, Suffolk, parts of Norfolk and Kent. We wished to overcome the increasing amount of interference caused by power lines and overhead telephone lines whilst on the move and the high number of household devices that cause interference within the home. Any perceived extension of our coverage area is incidental but obviously welcome.

We did receive numerous reports from far off locations saying our signal was still poor and could we increase it some more. Sadly not, as we are licenced by OFCOM to provide a community radio service in the aforementioned areas and that limits the power we can use. Any further increase in power would also significantly increase our electricity costs too as high power radio transmitters have a phenomenal appetite for electricity. We must always be aware of the vagaries of medium wave transmission and reception, and during these winter months the signal may well travel much further and give a fairly steady daytime signal in remote locations, but once the days start to lengthen again in the spring, that reception may well tail off. Night-time always gives extended range to our signal and it has been heartening to see reports from as far away as Portugal, Italy, Czech republic and Northern Finland. Of course, whilst our signal travels a long way at night other stations on the same frequency also travel further and often reception of Caroline in areas with a fair signal during daytime will have poor reception and much interference at night.

A fair number of reports mention our audio quality, and this is something we are aware of. We woud like to point out that options for reliable high speed connectivity at our transmission site are somewhat limited, and we are currently using a 64kb/s feed to site, which can tend to limit quality. However, many of the reports also suggest that our audio quality is excellent, so it is very much both a personal taste and a function of the radio you are listening on. Hopefully we can make adjustments to this to everyone's satisfaction in due course. For those with an interest in such matters we are using the same DSPx processor we installed in 2017 and the new transmitter is a Harris DX25U, previously located near Rotterdam and used on 828Khz. We are running an authorised radiated power of 4kw from the omni-directional "reserve" antenna at Orfordness.

For those who sent in comprehensive reports and requested a QSL card we will try our best to get acknowledgments issued as soon as we can. As always, please bear in mind that we are all volunteers and already give significant amounts of our free time to keep Caroline on air and there are a LOT of requests!


Harris DX 25U Transmitter
Two views of our new transmitter part way through its rebuild.
The Harris DX 25U is a 100% solid state unit with digital Amplitude Modulation.

Harris DX transmitters boast a typical efficiency of over 83%, resulting in the industry's lowest power cost. They also contain a lightning protection system and broadband interchangeable RF amplifier modules to simplify remote maintenance.
Pictures: Ray Clark