THE PAST WEEK
Saturday. The net-via-repeater was another success.
Sunday. Club members assisted the Armistice parade with radio communications
Tuesday Saw a committee meeting at which one hopes the principal matter discussed was the OUR OWN CLUB PREMISES.
Wednesday. The meeting was well worthwhile as always, punctuated by Norman’s hilarious stories about the things he encounters on Britain’s highways. The club radio was on full song for members to operate if they wished .Tickets were on sale for the Christmas party, but suggestions that the 5 quid admission money should include a welcoming drink and half a bottle of wine with the supper, met with a very cold response.
RALLIES THIS WEEKEND
Sunday. Hustle up the M23 to COULSDON amateur transmitting society annual bazaar.
. Admission price of £1.50 includes free coffee so you’re in profit right from the start.:-) Seriously though, those of you who think of learning useful things by building them should stop paying silly prices on ebay and get around to weekend rallies for cheap useful bits and bobs.
THIS WEEKEND ON THE RADIO
(It is a positive feast of top-band stuff BTW You _have_ put up your multiple of 43 ‘ doublet , right?
The ARRL SSB Sweepstakes Contest,
ARRL EME Contest, (Helluva big moon this week)
All Austrian 160-Meter CW Contest,
REF 160-Meter CW Contest,
RSGB 2nd 1.8 MHz CW Contest,
NCCC RTTY Sprint, QRP 80-meter CW Fox Hunt,
NCCC CW Sprint, YO International 80-Meter PSK31 Contest,
LZ DX Contest for Norman to speak Bulgarian,
**** Homebrew and Oldtime Equipment CW Party***
The Run for the Bacon QRP CW Contest is scheduled for November 21
The Phone Fray, CWops Mini-CWT CW Test and SKCC CW Sprint are scheduled for November 23.
Forthcoming Club Meetings
Please Note : The meeting formally begins at 8 but doors are open from 7.15 so arrive early to grab any freebies and tell lies about DX you have worked
- Construction Competition – Wed 23rd November – 8:00 pm – 9:45 pm •
- Club Evening – Wed 30th November – 8:00 pm – 9:45 pm •
- Sunday Breakfast Meeting – Sun 4th December – 9:00 am •
- Test or Practical Evening – Wed 7th December – 8:00 pm – 9:45 pm •
- Christmas Party Orgy – Wed 14th December – 7:30 pm – 9:45 pm •
- Club Evening – A really thoughful chairman would bring us all Christmas presents. Wed 21st December – 8:00 pm – 9:45 pm •
- Christmas inebriated nets TBA
- On the repeater evening. – Wed 28th December – 8:00 pm – 9:45 pm •
- Hungover Sunday Breakfast – Sun 1st January – 9:00 am •
- Club Evening – Wed 4th January – 8:00 pm – 9:45 pm •
- Thereafter ??? Someone wake up the website !!
Last week week , tucked away in DX news, was inserted a paragraph asking anyone who read it, to email me. No-one did so I conclude, gentlemen, that no-one reads DX news So it is discontinued.
You should go to:
he’s much cleverer with it than your humble scribe.
This weeks Sermon :
There is NO such thing as a MONOPOLE . For the physics explanation buttonhole G1EXG but for practical radio engineering read on :
Before an electrical charge i.e. a whole bunch of electrons, can be pushed up an antenna element, they have to come from somewhere; they can’t be created from nothing. A transmitter is bit like a pump, or a mouth organ, if it has nowhere to suck from, it can blow nothing out.
With a vertical dipole,this is easy to understand; charges are drawn from the bottom half and pumped into the top one then sucked back down again and pumped into the bottom one 7 million times a second. “But” you say “I’ve seen quarter-wave verticals working by themselves” What you don’t realise is that it needs an earth connection and the electricity is drawn out of the earth pumped up the so-called monopole and pumped back into the earth, the Earth is acting as one of the poles. In the wrongly called ground plane antenna, the charges are drawn out of the of the radials. “aha” I hear you say, “but what about the handheld rubber duck.?” Well, the same facts of life apply. The charges to be pushed up the rubber duck must come from somewhere. In the old days when handhelds were quite large and had a metal case the charge came substantially from the case of the radio but also,to some extent, from contact with the hand. Now that handhelds are very small and in a plastic case, things are different. The PCB inside acts as one plate and your hand outside the plastic the other to form a capacitor through which the antenna currents can flow up through your body. You will all have experienced the fact that putting your finger on the aerial terminal of a receiver produces lots of signal because your body is acting as a receiving antenna and in the same way, it can act as a transmitting one.
The trouble is your body is a lousy conductor. ( and this is just as well because otherwise you would be electrocuted by a 12 V battery). it functions as a very inefficient ‘other-half’ of a dipole… Using a hand-held antenna with just one antenna element is like trying to play a mouth organ through a drinking straw, no matter how hard you suck and blow, what comes out is very feeble.
What to do ? Well , you must replace your body with something better [no,. not by going to the gym and pumping iron,] but taking your body out of the RF circuit altogether. Give the radio a better place through which to suck and blow ! This is easy enough, get yourself 24 inches of insulated, wire strip the plastic for three inches from one end , wrap the bare wire around the bare metal part of the antenna base. With a BNC plug you have a nice lump sticking up to wrap around, with an SMA there is a threaded plug at one end or other around which you wrap your wire before screwing it into position. Trim the length of the wire to 19 and a half inches for 2 metres and let the wire hang down. You’ve made a dipole !! Both for transmitting and receiving you will find a tremendous improvement. Run tests with a friend if you like, or observe the better signal you get from some distant repeater. It costs nothing and takes about 10 minutes to make. I mean, like, it’s cool, man !
70 cm? Will have to wait for another day.
Bryan – G3GVB