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June 1985

Beechlog
 
The on-line magazine of the Burnham Beeches Radio Club.
INDEX AND ACKNOWLEDGEMENTS


ISSUE No.14 JUNE 1985

Page 1................Index
Page 2................From the Chair
Page 3................Library
................Club Equipment+Video?
Page 4................News and Views
Page 5................Last Bit
Page 6................Learning Pascal
Page 7................HF Aerial Programme
Page 8................Listing cont'
Page 9................For Sale and Wanted
................Oman!
Page 10...............Tech-Ed's Notes
Page 11...............Diary of Events
Page 12...............Membership List
Page 13...............Membership Form



Editor................Dave Chislett G4XDU
Technical Editor......Dave Lomas G4XOW
Printer...............Dave Ayres G6GBC
Computer Editor.......Mike Brown G4RAA

****************************************************************

B.B.R.C. COMMITTEE

Chairperson...........David Ayres G6GBC
Secretary.............Paul Robinson G6DVC
Treasurer.............Lynas Newton G6LYN
Member................Dave Bentley G6LKZ
Member................Bruce Gilson G4WVX

Library...............Stored at Haymill
Club Equipment........Stored at Haymill
For details see elsewhere in issue
To borrow any item see a member of
the committee.

****************************************************************

New Club Rooms...........Haymill Community Centre
112 Burnham Lane
Slough. SL1 6LZ
There is no telephone available at the Centre


FROM THE CHAIR

Well now, would you 'adam and eve' it ?
Guess who has now held every position on the committee ? (Answers
on a postcard please - to the Ed). Still, perhaps one day I'll get
it right.

I must first thank all those members who didn't vote for me, people
with taste one must assume. To those who did vote for me you must
have got the name wrong - now look what you've done !

I trust that I have just been unlucky with the first meetings as
Chairman but I am somewhat concerned to say the least. The Foxhunt
was a washout due to the weather (Beyond even my control, I'm
afraid ) and the first meeting in May had to be cancelled at short
notice - my fault for not checking with the Haymill Centre earlier.

Whilst on the subject of Haymill there are a few things I wish to
draw your attention to. First of all, the August Bank Holiday will
not affect our normal meeting. Secondly, perhaps YOU would prefer a
different day or maybe just an alternative for one of the Two
meetings ? Let me know your thoughts and ideas. Thirdly the bar.
Aha ! you cry, now the idiot is talking about something
interesting. If you did not already know, the bar is now
operational during specified times, (see notices in Haymill -
alright I don't know yet !).

To use the services of the bar you have to be a Haymill member or
be signed in by one, )If they've got the book yet !). Membership of
the B.B.R.C. includes Haymill membership: (What absolutely
terrific value ay ?).

Full rules for the bar use and times will be displayed shortly.

If it has not already been arranged, please let me know if you can
donate either time, advice or parts towards the club station. We
have had a generous offer of an aerial and rotator from John G4XJN
and obviously hands will be needed to help erect these along with
the existing Club equipment - let me know if you can help.

Something a little more positive is our involvement with the
McMichael Rally on the 21st July. We will need all the volunteers
we can find to do the Rally justice. As it is a significant source
of income as well as good fun we do expect a special effort from
everyone who is able. Let either Dave G6LKZ or myself know if you
are available to help, BEFORE or during the Rally, (e.g. Operate
talk-in; put up road signs).

FROM THE CHAIR CONT'

We will be holding more foxhunts and wish to be advised of your
preference of time and day - again let me have your (repeatable)
thoughts.

Any requests for future meetings or events are most welcome.

Well I think that will do for the time being, so Ta Ta, 73's, 10-4,
all them golden numbers to ya' and see you soon.

Chairperson David G6GBC




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CLUB LIBRARY

HF Antennas for all Locations Moxon
1981 Call Book RSGB
1984 Call Book RSGB
Radio communications Handbook RSGB
R.S Components Cataloque
Confidential Frequency List
+Supplement

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CLUB EQUIPMENT

1. 25ft Telescopic Mast/base/guys & pegs (Haymill)
2. J-Beam 2mtr+70cms Beam/cables (Haymill)
3. 4x23 ele JVL 23cms Beams (G4XDU)
4. Tent+Awning pegs (G4XOW)
5. G5RV HF Aerial/cable (Haymill)
6. AM. HF Transceiver 'valves req' (Haymill)

-----------------------------------------------------------------

The club has started to make a Video of the club activities
starting with the DX Picnic. During the next foxhunt there will be
a roving camera about, and at one of the forthcoming club meetings.
We hope to compile a video to show at the McMichael Rally. If you
have any suggestion for items to be included please let the editor
know.



NEWS AND VIEWS

Firstly in this issue, I think everyone has heard about the change
to the editor of Beechlog. Well, if you haven't, it seems that the
DTI gave me the wrong call-sign on the changeover to the G4. It
only came to light when the renewal came through from the Post
Office with the wrong Call-sign on it. On asking for the corrected
validation document i.e with old call-sign, I was informed that it
was wrong and there had been a mix up. Well I now have a nice new
licence and a photo-copy of the old to prove they made the mistake.
-------------------------------------------------------------------
Talking of call-signs, some time ago Mark and Sue G8ZRT/G8YKU
popped in while in the area. Both have passed the morse test and
have changed their G8's to G4's. Sue is taking a Degree in
electronics and Mark is still with IBM jetting around the world.
-------------------------------------------------------------------
This issue sees a new committee elected at the AGM. This year saw
two candidates standing for Chairperson quite unknown in recent
years. Our new Chairperson David has asked for your ideas and
suggestions for things to do. PLEASE give this a lot of thought and
pass the suggestion on. Normally we work on the principal that if
we hear nothing then you must be happy, but the attendance at
meetings and other events has been falling off and there must be a
reason. PLEASE PLEASE tell someone?
-------------------------------------------------------------------
The spring DX Picnic is now behind us and for once the weather was
kind on the Saturday. Several members got sunburnt and one person
missed the event because he couldn't find us! Unfortunately, the
generator we normally borrowed was not available, but an old friend
of the club, G8ZWS Ray, came to the rescue with a 1200Watt
generator, which unusually was easy to start and bring to the site.
I would like to thank Ray who has said we may make use of the
generator as often as we wish. We were in a different field from
last time, but all there agreed it was by far the best to date.
Radio took up a fair amount of time with contacts around the world.
However 2Mtr operation took a back seat due a contest over the
weekend. Stations we think only a mile or two away flattened both 2
and 70cms, however, later on Saturday evening, calling CQ on SSB a
number of stations from Wales came back desperate for anyone to
have a ragchew with.
-------------------------------------------------------------------
While at the DX Picnic I was handed an article from one of the
national newspapers. The headline read 'Radio Ham Cancer Risk'. The
article went on to say that Hams and TV repair men run the risk of
developing blood cancer. It appears that researchers in, where
else, the USA reckon that almost twice as many Hams die of
leukaemia than the national average. The cause is said to
be and I quote, ' electromagnate fields generated by the
equipment'. So be warned, like eating, drinking, and having sex,
radio is bad for you!!
-------------------------------------------------------------------



The Last Bit


IN THE COLUMN THIS QUARTER :
Results of the computer questionnaire, review of two books on
Pascal and an HF antenna design programme.


QUESTIONNAIRE

I have now had time to look at the computer/morse questionnaires
and here are some of the statistics:-

There were 11 replies out of 32 magazines distributed, which by
club standards is quite a good response. 3 of the 11 did not own a
computer, the remaining 8 own a wide selection of computers. In all
there are 8 different types in use, although some people owned more
than one micro.

The obvious conclusion from this is that any listings I include had
better be in plain and simple Basic, rather than in anything too
machine specific!

Most of the computer owners (6/8) have printers, with a significant
number owning monitors, disk drives and RTTY terminal units. The
most wanted peripheral (3/8) was a monitor, although several wanted
a modem, T.U. or printer.

When it came to software, Amateur Radio applications programmes
were (predictably!) most popular. Half the computer owners had more
than three of the program types on the list. The most popular being
a morse tutor (6/8) followed by RTTY (5/8) and logbook (4/8).

There were few 'wants' when it came to software -a sign of waning
interest? Generally the 'communication' type programmes (like RTTY,
CW, ASCII) were the most sought after.

Moving on to the Morse section of the questionnaire, the most
popular method of learning was from cassettes. Due no doubt to the
BBRC morse class tapes. Slow morse transmissions were also very
popular (they're free!). 60% of those learning morse used a
computer whilst 30% used records or a morse tutor.

Most of those learning morse used multiple aids. I must say that I
found this to be the best approach. Using several different aids
gave some variety to what could be a very boring slog.


LEARNING PASCAL?

I have just finished reading two interesting books on Pascal. The
first is called BASIC & PASCAL IN PARALLEL, by S.J.Wainwright. It
is one of the slim Babani volumes, and is a brief 60 page guide to
the differences between the languages.

I have to admit that I don't generally like the Babani books,
because they seem to skim over all but the most major details. That
said, the book does give a better idea of the way Pascal works
than, say, a magazine article, without going into the masses of
detail found in a full textbook. All in all it is a useful and
cheap (#1.50) introduction to Pascal.

MASTERING PASCAL PROGRAMMING by E.Huggins is one of the Macmillan
Master series. At #2.95 for 269 pages it rates as even better value
for money than the Babani book, or most other computing books for
that matter. The Master series is a sort of 'teach yourself' range
of books, covering topics from data processing to hairdressing,
hence the low price.

I spent a long time in Foyles bookshop in London, looking through
about twenty different Pascal textbooks only to give up in disgust,
as most of them seemed aimed at either the data processing
professional or computer student using a mainframe. The prices were
all in the #10 to #20 range too. Fortunately I came across this
book in the Maidenhead branch of Hammicks, and I must say that I
think that it is both better and cheaper than the others.

Eric Huggins is pretty good at explaining the way Pascal operates.
In 18 chapters he takes the reader through the ins and outs of the
language in a very readable way. He somehow manages to tread the
thin line between over-simplification and the more usual sin of
failing to explain something vital because the author thinks that
the reader must already understand something which is so blindingly
obvious to him.

In conclusion, this is a much better book than the Babani volume,
giving a good grounding in all the aspects of using Pascal. It is
however definitely for those who have already decided that Pascal
is the language for them.


H.F. ANTENNA DESIGN

I have included a listing this time so please let me know if you
think the programme is useful. It is pretty well REMmed so I won't
explain it here, suffice it to say that it should run on almost any
Basic, even Commodore.


10REM HALF-SIZE DIPOLE DESIGN
20REM USING LOADING COILS
24REM
25REM (C) M.P.B.BROWN 1985
26REM
30CLS
40PRINTTAB(1)"** LOADED DIPOLE DESIGN PROGRAM **"
50PRINTTAB(1)'"THIS PROGRAM REDUCES A DIPOLE TO HALF "
60PRINTTAB(1)'"SIZE AND PUTS A LOADING COIL IN THE"'
70PRINTTAB(9)"CENTRE OF EACH SIDE"'
75PRINTTAB(3)'"N.B. FEEDPOINT IMPEDANCE IS 22 OHMS"''
80D=0:Z=0:I=0:B=0
90@%=&20207
100INPUT"HOW MANY FREQUENCIES ARE YOU GOING TO"'" ENTER (MAX
10) ",Z
110DIM F(Z)
120FOR I=1 TO Z
130INPUT'"FREQ (MHz) ",F(I)
140NEXT
150FOR I=1 TO Z
160F=F(I)
170A=234/F
180B=58.5/F
190X=A-B
200Y=((A/2)-B)
210IF D>0 THEN 280
220CLS
230INPUTTAB(0,17)"DO YOU WANT TO USE THE WIRE TABLE Y/N",Y$
240IF Y$="Y" THEN PROCwiretable
250IF Y$="N" THEN PROCdiameter
260IF Y$<>"Y" AND Y$<>"N" THEN 230
270CLS
280S1=1E6/(68*3.1415^2*F^2)
290S2=1/X*(LN(24*X/D)-1)
300S3=(1-F*B/234)^2-1
310S4=1/Y*(LN(24*Y/D)-1)
320S5=(Y*F/234)^2-1
330S6=S1*(S2*S3-S4*S5)
340IF I<>1 THEN 380

350PRINT'''" FREQ "," TOTAL"," CENTRE"," COIL"," WIRE"
360PRINT" MHz "," LENGTH"," TO "," IND"," DIA."
370PRINT" "," FEET "," COIL "," uH "," INCHES"
380PRINT'F,A,B,S6,D
390NEXT I
400END
410DEFPROCwiretable
420INPUT"WIRE SWG (10 TO 28)",D
430IF D=10 THEN D=.128:ENDPROC
440IF D=11 THEN D=.116:ENDPROC
450IF D=12 THEN D=.104:ENDPROC
460IF D=13 THEN D=.092:ENDPROC
470IF D=14 THEN D=.080:ENDPROC
480IF D=15 THEN D=.072:ENDPROC
490IF D=16 THEN D=.064:ENDPROC
500IF D=17 THEN D=.056:ENDPROC
510IF D=18 THEN D=.048:ENDPROC
520IF D=19 THEN D=.040:ENDPROC
530IF D=20 THEN D=.036:ENDPROC
540IF D=21 THEN D=.032:ENDPROC
550IF D=22 THEN D=.028:ENDPROC
560IF D=23 THEN D=.024:ENDPROC
570IF D=24 THEN D=.022:ENDPROC
580IF D=25 THEN D=.020:ENDPROC
590IF D=26 THEN D=.018:ENDPROC
600IF D=27 THEN D=.0164:ENDPROC
610IF D=28 THEN D=.0148:ENDPROC
620PRINTTAB(1)"WIRE GAUGES MUST BE A NUMBER"
630PRINTTAB(1)"IN THE RANGE 10-28"
640GOTO420
650ENDPROC
660DEFPROCdiameter
670INPUT"WHAT IS THE ELEMENT DIAMETER IN INCHES",D
680ENDPROC
700REM TO CONVERT THIS PROGRAM TO RUN ON COMPUTERS OTHER THAN THE
BBC
710REM 1) LINE 90 IS JUST TO ALTER THE NUMBER FORMAT, DELETE IT
720REM - THE PROGRAM WILL STILL RUN
730REM
740REM 2) REPLACE PROC WITH GOSUB i.e. PROCdiameter BECOMES
GOSUB660
750REM
760REM 3) REPLACE DEFPROC WITH REM i.e. 660DEFPROCdiameter
770REM BECOMES 660 REM diameter
780REM
790REM 4) REPLACE ENDPROC WITH RETURN
800REM
810REM REPLACE LN WITH LOG - LOG TO BASE e IS LN ON THE BBC

FOR SALE OR WANTED

UPDATE YOUR QSL'S WITH YOUR NEW LOCATOR. Simply send your new
locator (your National Grid Reference will do).
Locator rubber stamp #3.49.
"Please QSL" stamp #3.49. Pad #1.39.
Mike Brown,
4 Roebuck Green,
Slough, SL1 5QY.
Tel. Burnham 4262
NB These prices include 12.5% discount
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
5.25" BIB DISC HEAD CLEANING KITS
#4.49 EACH
Mike Brown
4 Roebuck Green,
Slough, SL1 5QY.
Tel. Burnham 4262
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
WANTED:Ceramic wafer switches suitable for ATU.
Dave G4XDU Sl.21896
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
WANTED:
Information on AMTOR. G4XDU is trying to write a programme for
AMTOR on the Acorn Atom, however there seems to be a general lack
of information around about the mode. If you have any information I
would be pleased to hear about it.
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
GETTING A LICENCE IN OMAN

Just as this Beechlog was being compiled, a friend G4CMG, rang to
say he was back on leave from Oman. Tom has been out there for four
months. He expected to have a reciprocal licence quickly but when I
asked what the call was he said things were a little slow and
difficult out there.
If you have ever tried to get a reciprocal licence for France and
thought that difficult read on. Getting a licence in Oman requires
firstly belonging to the national society. No you don't go along to
the local Rally and sign on at the RSGB stand. Joining the national
society is like trying to become a member of Wentworth golf club
and equally as expensive! Firstly, you must be resident in Oman for
three months; then you need a sponsor in a position of importance
i.e. your employer, plus the recommendation of two Society members,
i.e. licenced amateurs not easy when there are only a few in the
country. The annual fee must be enclosed with the application #50!
plus six copies of your passport photograph. Enough, I hear you say
but they also, if you are basically acceptable, call you for an
interview. By the way they only interview once a month! They also
require at least two Omanies to each foreigner so it could be a
long wait. Given up yet? Well you have only got into the national
society, you have still to apply for the licence........

TECH - ED'S NOTES

Time has leapt on since the last magazine, and yours truly has left
this contribution till the last moment.(Way past the last moment
ED!) My comment last time on my 10 metre interference was answered
about a week later when the DTI telephoned to say they were sorry
for taking so long in having a filter fitted to the nearby
telephone system, but they were having trouble getting co-operation
from B.T. Well filters were fitted, but nothing happened so
I shall get the RSGB involved and let them try and sort it out.
There have been a number of good lectures at the club. I remember
after the one on Aerial Matching, I was all keen to make up a an
ATU to his ideas, but somehow the patio in the back garden seems
to be progressing faster. One interesting point that I read
recently, is that whilst for transmitter matching, it should
have a low-pass characteristic to reduce harmonics, for receive
purposes a high-pass is preferred, this helps compensate the
increase in atmospheric noise which occurs at lower frequency.

I was looking forward to the D.X Picnic that Dave G4XDU (must
change all those W's to U's in the log book) organised. It was for
me the best one to date. We were nearly caught out for lack of H.F
equipment, but fortunately my FT7 for which we had no A.T.U
performed suprisingly well. The match on the half-size G5RV was
adequate for direct running on 40,20 and 10 meters. A number of
interesting contacts were made and we did hook up an Acorn Atom
based RTTY machine to the FT7, this took some time due to the
stupid connection differences between Yausu and FDK on the 4 pin
mic socket.

For some time I have been using the computer (BBC), with
the radio equipment for RTTY, SSTV and morse. The problem is that
most of the currently available machines have made no attempt to
reduce radiation of interference. G4XDU has solved this by
repackaging in a metal case. Mike G4RAA found details of an acrylic
copper loaded paint, which we have subsequently purchased and
applied to the inside cases of both our machines. We sprayed using
a set up for car spraying, but a small aerasol dispenser and hand
painting were also successful. We found that it is necessary to
thoroughly clean the surface as substances used during manufacture
can prevent good adhesion. The results on VHF are good, We shall
have more details of the results in the next magazine. We have a
quantity left so if anyone wishes to purchase some then contact
Mike or myself.

The Mc.Michael Rally is not too far away, so please mention it over
the air. We would like to put on a good display this year. In
particular homebrew equipment so do bring them along. Must get back
to that patio.

73's DAVE G4XOW

DIARY OF EVENTS

4th Feb..................G3CWI Slide Show Antarctic
18th Feb.................G3JKV Aurora's
4th March................A.G.M.
18th March...............G3RZP ATU's & SWR
23rd March...............RSGB VHF convention
Sandown Park (Saturday)
1st April................FoxHunt (Please note usual
start Upton Park car
park)
13/14th April............RSGB National Convention
Birmingham
15th April...............G8DPH Demo A.T.V
6th May..................G4CGS H.F. propagation

18/19th May..............Spring Picnic (Sat/Sunday)

20th May.................G4END Slow scan T.V & colour
3rd June.................G3CWI Slide show ?
17th June................G4PHS R.F. filter design
30th June................Longleat Mobile Rally
21st July................McMichael ARS Mobile Rally

*****************************************************************

Further evenings planned but not confirmed..........
Moon-bounce
6Mtr operation
PMR equipment

*****************************************************************




MEMBERSHIP LIST


001 Eileen Chislett G6EIL Sl.21896
002 Dave Chislett (Editor) G4XDU Sl.21896
003 Tony Alderman G4LQD Fc.3286
004 David Ayres (Chairperson) G6GBC Md.28108
006 Paul Shayler G6TSF Sl.41396
007 Bill Perkins SWL Sl.32171
008 Lynas Newton (Treasurer) G6LYN Bn.66759
009 Mike Brown (Computer Ed) G4RAA Bn.4262
011 Dave Lomas (Tech-Ed) G4XOW Lt.Grn.2847
012 Ann Lomas SWL Lt.Grn.2847
021 Peter Harman G4XGD Sl.28826
025 Dave Bentley (Committee) G6LKZ Sl.25101
026 Kevin Hadley G4HDK 0734 731026
027 Graeme Platts G4XOF Sl.78495
030 Richard Ashberry G6RTM Sl.46012
031 Ted Swaby G4XOE Sl.75099
033 Dave Hemmins G6DRP Bn.64436
034 John Williamson G4XJN Sl.24008
038 Paul Robinson (Secretary) G6DVC Rslp.72125
043 Bruce Gilson (Committee) G4WVX Bn.64415
047 Peter Melling G1LHU Sl.29025
048 Mike Gathergood G4KFK 0895 834167
049 B. Mockett G1DSI ********
050 T.Kay G4ZTK Bn.4255


*******************************************************************

Please note if your details are not correct please the form on the
back of the magazine and hand to a committee member. This will help
us to keep the records up to date.

*******************************************************************

THE BURNHAM BEECHES RADIO CLUB

G3WIR G6WIR

The Burnham Beeches Radio Club, affiliated to the Radio Society of
Great Britain, serves the Slough/Windsor area, although it got its
name from its original meeting place - or that vicinity.

We meet twice a month, and our activities cover a wide range of
topics related to radio communications, such as lectures,
demonstrations, and club operating nights; there is also a keen
interest in home computing among our members.

We welcome members of any age and sex, who have an interest in
Amateur Radio, whether they be licenced amateurs or 'Short Wave
Listeners'.

Meetings: 1st & 3rd Mondays of each Month at 8.00pm
Haymill Community Centre
112 Burnham Lane
Slough. SL1 6LZ
Secretary: Paul Robinson G6DVC. Telephone. Ruslp72125.

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MEMBERSHIP DATA FILE

NAME:.................................... CALLSIGN:................
ADDRESS:................................. DATE:....................
................................. TELEPHONE:...............
................................. POSTCODE:................

BANDS WORKED: HF( ) VHF( ) UHF( )
MODES USED: CW [ ] SSB [ ] FM [ ] RTTY [ ] ATV [ ]

MAIN INTERESTS: (Building, contests, ATV, RTTY etc;)
...................................................................
...................................................................
...................................................................

SUGGESTIONS FOR CLUB ACTIVITIES:
...................................................................
...................................................................
...................................................................

COMPUTER INTEREST:...................... MODEL:...................
[All details held in confidence by the committee]

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