THE CATSWHISKER - JULY 2000
Newsletter of the South Dorset Radio Society
Editor - John Rose, M0BQO - 45, Ringstead Crescent, Weymouth. DT3 6PT
The SDRS Annual Barbecue and Car Boot Sale will be held at the usual venue, the Victoria Inn, just west of Chickerell Village on Tuesday 4th July.
No meeting in August !
Radio Hams Do It With Frequency!
Greetings yet again to all members and readers. Did you blink recently? If so, you missed summer: there were just a couple of days when Weymouth basked in sunshine, and a few others when the rest of the county did and we were enveloped by a sea mist.
Portland wore a beret too, as damp air had to rise above the island. Following the logic of the Seasons there have been quite a few visitors, and amongst them it’s good to hear some Radio Amateurs operating either HF mobile or through the Repeater.
Fingers crossed that true summer is upon us for the BBQ and Boot Sale on July 4th.
Apparently there is a movie released now called ‘Frequency’, a supernatural sci-fi tale involving Ham Radio. Sounds interesting.
Thanks for keeping all these pieces coming in - Catswhisker is almost writing itself now.
John, M0BQO
Dates for your Diary
July 4th is the SDRS’s annual Barbecue, combined again with a Car Boot sale - radio items mainly. Members, guests, friends etc will be welcome but a voluntary donation of £1-50 would be appreciated from non-members who wish to sell.
There is no meeting in August but news of the September meeting and onwards will appear in due course.
MISTER TEN PER CENT!
Jim Barton, G7JIM will once again have a table at Flight Refuelling’s Hamfest on 13th August. Last year he sold a lot of items and donated 10% of the takings to the SDRS. He will do the same again this year, hoping to net at least £50 for the Club.
Anyone who has articles to sell and would like to dispose of them in this way is welcome to leave them with Jim on the day, or otherwise contact him on 01300 348790 or 01300 348131.
Jim, who is also dealing with the International Marconi Day QSLs says that they have now started to come in (including some from previous IMDs!)
SDRS Chairman Robert, G0RYL delivered an interesting talk about meters; their setting up, calibration and trouble shooting. Here are a few tips he suggested.
Types of meter:
Moving Iron Meters have fallen out of favour but can still be used to give a reasonable measurement of output power.
Moving Coil Meters are the standard norm, and most of his talk centred on these.
Digital Meters are favoured by some. A digital meter is more accurate than an analogue one of similar quality but does not have a needle to instantly show a trend. (This point gave rise to some discussion, though it was clearly a case of using whatever best served one’s purpose.)
The Needle:
If the needle moves freely, all is probably well.
If the needle does not move freely, then:
The spring may be broken or kinked;The needle may be bent;The needle may be rubbing on the dial.
Re-setting the needle:
Bear in mind that the needle may zero at centre, or at one end of the scale. Robert described how it could be done with a screwdriver, a soldering iron and a built-in sliding weight should the needle movement be abnormal.
The Spring:
This is vitally important. It should return the needle to zero, and it conducts the current that causes the needle to move.
Voltages:
For measuring voltages, a meter needs to have as high a resistance per volt as possible to achieve maximum sensitivity. Typically this should be at least 20,000 ohms/volt. The correct voltage range is switched in from an array of different value 'multiplier' resistors.
Current:
As a meter can easily be damaged by a heavy current rushing through, a shunt resistor is usually fixed in parallel to divert excess current away from the delicate mechanism. Again, an array of such resistors is available depending on the anticipated current. (Always select highest current range first.)
Accuracy:
A meter needs to be calibrated, ensuring that it is accurate at all points on its scale.
The National Standard Meter, against which all meters are tested, is at the National Physical Laboratory. The ones Robert uses at work are checked against meters that are at the first or second level of checking; most are at least five levels down.
HOW TO WORK THE WORLD ON A HANDY!
One evening I had a text message on the Orange 'phone from John,G8IKP who was in Chicago to contact him by e-mail. I had been away on holiday and had not logged on for a week. What he wanted me to do was make use of the new facility of Internet Linking to and from Amateur Radio.
I duly logged on to the web site he suggested ( http://freespace.virgin.net/adrian.g7wfm/conferance.htm ) and found that he was already logged in and able to access Amateur Radio Repeaters all over the world! However as I had not at that time installed the software that was needed and was not in range of G7WFM we were not able to manage a QSO.
The next day however with everything set up I was not only able to have a voice chat with him whilst he was on the Internet but later worked him (John has a US call, KB9VIN/M) through N9RP-R, a UHF repeater in Chicago whilst he was at the airport waiting to board a flight to Minneapolis! My access to the repeater was just the same as if I was using a radio. It is possible for either or both stations to use Radio or the Internet for the QSO and repeaters are coming 'on line' all over the world so when 'SD joins the net (John has already applied to set up an Internet Link to 'SD) it would be quite possible for me to chat whilst walking the dog in Weymouth through 'SD with stations the other side of the world.
If you want to have a go you need to download and install the 'Iphone software' available from the above site.
73 de Geoff, G0EVW
APPEAL FOR YOUR MEMORIES
The society will celebrate its 40th birthday next year, 2001. It would be fitting to produce a booklet telling the story of SDRS during those years.
We are asking now for anyone who can chip in with a memorable tale, a suitable reminiscence, a picture - particularly one that tells or illustrates an event, to come forward and let us share it.
It may be your own memory, or perhaps you can ask previous members for theirs. In particular, let’s make a special effort to focus on the earliest years, as nearly all of us are OK with the later ones.
Personal tales, club events, personalities, good times, bad times; it’s all part of the story and we will all enjoy hearing it.
THE PW QRP CONTEST
Date: 18th June 2000.
Venue: Hardy's Monument.
Weather: hot and sunny.
Working Pat's G1XJH Icom 746 on the 144MHz band USB, at 3 Watts through a beam atop a 30-ft mast the results were:
101 contacts in a total of 26 Squares giving a score of 1926 points.
Some of the CB fraternity, and other interested listeners, appeared on site to give support and pass greetings.
Pat thanks all who participated, mentioning specifically Richard 2E1HSI who handled the QSOs very well, and achieved the one hundredth QSO.
AMEN
Well, after all that cajoling (alright - coercing ) this is the final reminder for those who have not renewed their SDRS subscription.
You will appreciate that the SDRS is not large, while our overheads are, and everyone who renews helps enormously.
Reluctantly we shall have to say a sad farewell (hopefully, au revoir) and that means no more Catswhiskers until late renewers cough up.
Our Treasurer Emma, M1CCJ will be pleased to receive your offerings. Please make cheques payable to the South Dorset Radio Society.
Her address is:- Emma Illsley, 15 Victoria Place, Easton, Portland. DT5 2AA.
AND FINALLY
Thimbles are now very popular collectors items - and they don’t have to be old. Here are a couple from a set called 'Landmarks of Communication', recently commissioned.
The Ferranti Model 145 was the first UK domestic receiver produced after World War II and cost £15.00
The PAM 710 (1956) was the first British all-transistor radio and cost £31.50 (That equates to about £1000.00 in todays money for a MW/LW battery operated portable radio! - Ed.)
John, MoBQO
STOP PRESS - Just posted on this site Morse code training in the RAF by George, G3AVV