David Kwaku Celestin

Engineer David K.Celestin

David is an entrepreneur from Ghana, he studied Electrical Engineering at the Textiary Institution and as a result he builds FM transmitters. The following interview was conducted by email and uncovers how he goes about doing this along with some of the problems he is faced with as an African Inventor.

Hi David

Where or how did you learn the skills to build your radio transmitters?

>>I didnt attend any specific place to learn how to build a radio transmitter. To me it’s a talent I was born with because I have been doing so many creative things. Art has always interested me and iv’e always been somehow curious about nature and the way things behave the way they do. I used to build model aircraft when I was in primary school and junior secondary school for science exhibitions.

How did you build it, were you supported in anyway?

>>I started with Intercom system and then advanced to an FM microphone. The breakthrough was a wonderful dream I had on how to go about actually building the transmitter. I always perform my own calculations because most project circuits published on the net are problematic and do not work well if at all. By performing the calculations myself, I will have confidence in the project from the very first step. The secret is getting the right information; I do a lots of analysis and combine formulas using logical/creative thinking. With a little information on the phenomena of electromagnetic waves, and being able to interperate components datasheets, I was able to build a 5 watts FM transmitter in the year 2004/2005.

60watts RF amplifier

I didn’t get support whilst building it for there is no one in Ghana who builds radio transmitters. Technicians working at FM/TV stations I contacted were not at all helpful or encouraging. All they said was “they have attempted it themselves and it did not work”. I was convinced it had worked because they worked with transmitters. At this point I was searching for a solution for a humming sound at the receiver end, and when I asked for advice many engineers and technicians told me to give up, as they said a black man from Ghana could never achieve what I was trying to do. I then decided to use 12V car battery to power the transmitter, which worked very well. I decided to use pure DC power and pie filter (capacitor, inductor and capacitor), and was able to obtain a clean sound at the receiver end for the first time. There was still a little hum in the background of the music so I decided to use large values of capacitors (33,000uF/25V dc) at each end and an inductor of 1mH which I got from an old TV. Then I had an ultra clean 13.8V dc supply to the 5 watts transmitter.

The next problem was the interference. I did a lot of research on the net, but did not come up with anything. I managed to combined several different approaches and finally overcame the problem. I had two solid years of difficulties which I did not give up, and this eventually led to my success building an FM radio transmitter. I then integrated a simple gain control.

Some useful PDF information from Freescale Semiconductor which I downloaded from the net also accelerated my performance in designing different RF power levels. I went from 5 watts(2SC1971) to 10 watts(2SC1972),20 watts(BLY89A) ,25 watts(BLY89A), 30 watts(2SC1946A),60 watts(2SC2694) and 150 watts(SD1460) .

I got some of the RF transistors and capacitors from two broken 145-165MHz transceivers. Of course they were not free. I paid for them, but unfortunately they broke down. If I am lucky, I will get the transistors reading well and they can be used again. If I’m unlucky I get sold faulty components. This does happen to me, so I have to look for other alternatives.

For trimmer capacitors, I sometimes modify them by adding dielectric mica plates used as isolators for heat-sinks by cutting the shapes to fit. For the inductors, I go for the laminated copper wire used for transformer winding/rewinding then calculate the inductance value using a formula and a scientific calculator. Metric convention is necessary so I have a chart. The RF amplifier photo tells it all.

RF Amplifier

How was the project funded, and does it generate any income for you?

I funded the project myself. People failed to support me in terms of funding because they doubt my abilities. I wrote to many companies for sponsorship in Ghana, thinking they would assist me in funding the project. Amazingly none of them even returned my call. Even the telecommunication companies did not support me. I asked for US$2,000 to enable me to order RF parts to build high power transmitters, but did not have any luck. My parents are not very rich so they could not help me, and they also doubted its success. In the end I was able to do some repair work for people (stereo power amplifiers, radio receivers, TVs etc) to raise some money for the project. As for income, I have made a little from it, about $800 so far. I have not made much as I don’t operate it continuously as commercial FM stations do.

What is the radio mostly used for?

I used it for renting bases. In Ghana, churches organize programmes like camp meetings, crusades and Easter conventions which they want their community and the surrounding communities to know what is happening and also use the medium to invite people to attend. It’s mainly a week or two weeks program. A church actually awarded me for designing the transmitter.

Award

I also use it in campuses to lecture Engineering students about inventions, science etc. and how to become a creative thinker.

You can visit www.davcel.blogspot.com to see some Seminar pictures.

Is the radio transmitter legal?

You mean have I registered the station with National Communication Authority? The answer is no, I haven’t done that, the radio is illegal but I make sure it doesn’t interfere with any other station. I tried applying for a liecence but it did not work out. I think the authority want commercial stations that can make them more money than a community station. That is one challenge here in Ghana. The commercial stations pay about US$8,000 to US$25,000 or more depending on the coverage range before they are given the license.

As a participant, what was your experience of the Maker’s Faire Africa?

It was the first time I realized that great Inventors are normal people like us, only they have the perseverance to do what they do despite the failures they encounter. I talked to inventors that I have heard of but never imagined meeting. People like Albert Einstein and Bill Gates become so highly respected when they help solve the world’s problems and I want to be one making life easy through technology is one of my priorities. It was wonderful to meet like minded people.

Radio at Makers Faire Africa

One memorible experience was when the participants were asked to use water and anything they could find (in the room/hall) to create something that would solve one of the worlds greatest problems. I was surprised because that means a lot to me. That is what I sometimes do when I’m limited with resources and can only use local materials to get what I want. [See water sachet pictures] I explained the generation of hydro power using an electric standing fan as Turbine and water sachet as a dam or water falls.
The faire mtrisector and inztanceade me feel very important as well. I didn’t realize my potential before, and was amazed that so many festival goers throughout Africa appreitiated what I was doing. It made alot of people think ‘wow, a Ghanaian man can do this?’. Finally, I emerged as a winner of the event. This obviously gave me some acknowledgement as well as encouragement.

Did the maker’s faire Africa help you and the project potential?

Yes, it did because I wasn’t fully convinced about what I was doing. This is because my own people nearly caused me to give up when I first started and some also said only a white man can build a Transmitter that would work.
Does the faire offer much support? Apart from the prizes I received as a winner I haven’t had any support from the organizers. The prizes were only gifts, like electronic kits, a story book and a solar bag. There were no cash prize awarded to the winners. I haven’t received any financial assistance from the maker faire organizers.

When faced with challenges of funding and support, do you see a sustainable future in this project?

Well, in one sense the future of this project is very bright but in another it’s something else. When I’m faced with the challenges of funding and support, I somehow want to give up and look for for something that can sustain me without me having to invest into it. Life in Ghana as well as well as all over Africa is becoming unbearable these days, one is afraid to be seen as a failure. The poverty level is increasing, though politicians claim it’s getting better now. People hardly eat a daily meal. So I believe in God Almighty that in time my dream will be realized.

How would you like to see the project develop, say in five years time?

In five years time, God willing if everything goes well in terms of funding and support, it will not only be functioning as a community station but also on commercial level. Also, a very big FM transmitters manufacturing company will be established here in Ghana. The community FM station will be expanded to cover the entire of Ghana.

Do you know of other inventors that are facing similar problems in Ghana?

Yes, I do. There are some I met at the faire and they also complained about similar problems. The very lucky ones are flown to Japan or the USA by their family members who are abroad. The unlucky ones generally end up giving up. It’s very sad to see problem solvers give up and the politicians go outside of Africa seeking for help whilst people around them can solve a similar problem. Human resource is not highly explored in Africa.

What kind of support do you need to take the project forward?

What I have realized in this world is that Human beings have unlimited needs no matter what one has. Back to your question, Financial and material support will definitely keep my project moving forward. Financial support in terms of funding, material support in terms of relevant information (books), components and the necessary tools for the job.

What are your personal ambitions for the content of the station, and what kind of importance do you think the role of the station plays in the community?

My personal ambitions for the content of the station is to expand it to cover different communities in Ghana especially rural areas which include farming communities, fishing communities, places where there are no radio stations. I also aim to broadcast commercially as I mentioned earlier.

As for the role the station plays, we are in the information age and the dissemination of information is very important. I would bet you that many people in rural areas do not know what is happening in the world. They only know how to eat and sleep. They hardly get access to share their views on radio and my station is going to do that. This will also increase the strength Democracy, farmers will be educated on new approaches in agricultural, and at election time the station will grant aspiring candidates the opportunity to tell the people their intentions. The other key point is the spread of Gospel, Islam and other community activities.

How often you able to broadcast and how many people are you reaching?

I broadcast as often as possible- when testing my new broadcast antennas and RF amplifiers, during Easter festivity, Christmas festivity, movements and camps organized by churches. Many people tune to my station because most of the commercial FM stations in Ghana (except BBC radio) talk of politics and many people are fed up with that. They think politicians are lairs, and so turn to listen to music from my station. I play a lot of music with less talk, lots of preaching messages and gospel songs, no politics at all.
I cover quite a large community at about 25Km or more in diameter. Sometimes when I’m going round checking the performance of the antenna I hear people listening with the volumes on their radio set very high, which is encouraging.

Does the internet prove to be a useful for yourself and others inventors in Africa when attempting to build projects without local support or expertise?

Yes, it has been very useful to me in the search for information like component Datasheets, and other relevant guidance. To me, not all the information I gather from the internet is useful. Some stuff is there to frustrate people and add to the lies. Most projects on the net are problematic ones and will only waist the time and resources of beginners. What I know in Ghana now is that engineers take me as an expert in radio frequency engineering for I have had a lot of experience in the field.

Also for other inventors, I will say yes internet has been useful to them as well. Because many of the African students and hobbyists across the world have been seeking my help when they visit my homepage- Here
Or Here and look at other articles I have published.

This means that most of them make use of the internet as their source of information on the project they are working on. I personally had over 700 e-mails from different people either black or white had requesting for TV transmitter and VHF 30 watts amplifier assistance.


COMMENTS / ONE COMMENT

[...] (MIT). David happens to be one of the exhibitors at the event, you can read more about his work here Here are some photos of David at the Faire: #gallery-1 { margin: auto; } #gallery-1 .gallery-item [...]

David – “The Radio Engineer” « GH Tech added these pithy words on Jan 27 10 at 11:01 am

SPEAK / ADD YOUR COMMENT
Comments are moderated.

XHTML: You can use these tags: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>

Return to Top