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Spurious Comments

Well as predicted It's been all hands to the pumps to get the TOC building stripped down in preparation to dismantle and move it down to 56 Friday Hill. It's been a busy few months let me tell you and no easy task with still loads to do for the new build.
The new building has been named "Friday Hall"  this became official in May


National Mills Weekend was still fun even though the club didn't take part this year. I heard six special event stations on 2m and 40m and made contact with the Havering radio club GB2UW on 145.575MHz. They were operating from their local Mill in Upminster, running ​50w from their FT847 using a co-linear​.




The furthest stations heard were up in Leeds, GB2TMI were operating out of Thwaite Mill and Nottingham GB2GG were operating out of Greens windmill

The clubs radio camp is almost on us again. Let's hope that camp this year is blessed with good weather thorough out, members are invited to show their support.

Finally I would just like to say welcome to our newest student Dieudonne. We hope that you enjoy your time here.

Michael M6MBM

Chairman’s Band

At last the club has moved to its new Headquarters (QTH) on FRIDAY HILL. It is a pleasant single story brick building with central heating and land at the back for us to use. It is adjacent to the main bus stop.  Plus some off road parking.

This move has taken place thanks to a lot of hard work by Peter, Tom, Clive, Michael, Rodney and some new members. Borough of Waltham forest now need to know  what masts and aerials the club needs to enable the council to give planning permission before work takes place.

We now have a rig working on 70cms, 6 meters & 2 meters and about 6 people have enquired about joining the foundation licence course.

There is still a great deal of work to be completed in the coming months on our new QTH. Please offer your help to Peter and Tom.

Do remember that the clubs radio camp is arranged for Friday 26/7/2013 opening at 12 midday through till midday Monday 29/7/2013. The site is at The Lambourne end centre, Manor Rd, Lambourne End, Essex. RM4 1NB
If you do not have a tent etc, just come for the day or each day and stay till the evening. Although we would like you to come for the whole time, your presence any day will be most welcome. This is when you can bring those bits you want to test without upsetting the neighbours.




Secretary’s Comments

As meetings become established at our new venue, it adds another piece of history to Amateur Radio in Chingford. The earliest meetings are traceable
back to the late 1920s/early 1930s where a club night would be hosted at a different members house each time. Silverthorn started off meeting in South
Chingford before moving to Friday Hill House, our brief time in the Tom Oakman Centre, and of course now to Friday Hall..

For decades, the club camp used to be held in a field at the end of Green Lane in Sewardstonebury. It was originally a piece of ancient Woodland, until 1957, when the trees were taken up on the understanding that new trees were replanted. That never happened, and the 1960s - 1980s saw the land used as grazing by horses. 

On regular occasions Silverthorn Radio Club was given

permission by the landowner to use the upper flat part of the field adjacent to the golf course to site an antenna farm, tents and caravans.

In 1997, the Corporation Of London had the opportunity to purchase this land called Fernhill, and the adjoining wood which runs alongside Mott Street known as Trueloves, and has incorporated both parts into Epping Forest.

Last year I walked through Trueloves and Fernhill. The views are still excellent but it is unrecognisable as the place where we used to camp, careful hedge planting and management have allowed the land to return to a natural forest setting.

Malcolm G0DPT

Bargains to be had!

RSGB Special Offers.
From their on-line catalogue
Some of the current special
Offers are web exclusives!
Buy today whilst they last!

Michael recommends …

JAB Electronic Components for Radio Hams

" We normally despatch items twice a week Mondays & Thursdays. We aim to complete all orders within 14 days from receipt. "

Rod recommends …

627 Romford Road
Manor Park E12

Tel:  020 8553 1174

My QRP Experiences...

Silverthorn Radio Club committee asked me to make use of their FT-817  and get it running again. I was particularly interested in the FT-817 commander software interface and I found something called weak signal propagation reporter (wspr) software that looked very interesting indeed..............

Initially, I took my laptop into the club and tried the commander software out using the adapter without installing any drivers. The interface when started found the radio and it seemed to be working, however when Tom, M5AJK suggested to try clicking on a band to change frequency, the frequencies I tried were not being shown in the display window correctly, for some reason they were displaying random frequencies. It turned out the reason for this was because the USB – serial adapter had not been installed properly! So we aborted this attempt.......

OK, next day and back in the shack. So once I had resolved the teething problems, i.e. my laptop only has USB, VGA, SD and Ethernet ports so to use the radio's CAT lead with my laptop I have to use a USB-serial-adapter. Vista does not always play ball with certain devices and on this occasion there was no change. I plugged the adapter in and windows detected it and went through the process of trying to find the driver then giving me the option to look for it myself. I had a USB-Serial-adapter driver already downloaded so I quickly navigated to my Linux file server where it was being held and chose the driver "ser2pl.sys" that was supposed to be compatible with Vista. All seemed well while it was installing the driver then all of a sudden the dreaded “Blue Screen of Death”

One good thing about Windows newer versions XP, Vista, Win7, they recover from this sort of problem very quickly. It did a dump and rebooted back to the login page.
It took me a couple of attempts & re-boots to realise that I was wasting my time, I then used the driver removal tool to get rid of the offending code. Once everything was stable again I had to search for a compatible driver, and came across “PL2303_Prolific_DriverInstaller_v110”, now here’s the thing! When I checked what was in the zipped folder the Vista driver was named “ser2pl.sys”. ​Alarm bells started ringing and I prepared myself for another disappointment

I went through the same process of installing the driver only this time, to my relief the driver was accepted and installed to COM 4. This was verified by looking in device manager.

While I was trying to find information about the driver I came across a useful tool that is built into Vista called “Driver Verifier Manager”. If you click on “start” then type run and hit the return key the run command line window appears. In here you need to type verifier and hit return. This brings out the “Driver Verifier Manager” window. Using this window you can test or verify all of the installed or not in use drivers on your machine to pin point a faulty driver. It’s a very useful tool indeed. So now at last I could get to the good stuff and test out the FT-817 Commander software and rig.

The FT-817 has 1w, 2.5w and 5w power settings, works on 70cms, 2m, 6m, 160m, 80m, 40m, 20m, 17m, 15m 12m and 10m. It comes supplied with a rechargeable battery and rubber duck antenna with 3 attachments. One is connected to the radio this is obvious as it has a BNC connection. The remaining two pieces one shorter than the other are screwed onto the first piece, your choice of which piece to use dependant on what frequencies you intend to work.

Most of a Saturday was spent playing around with the interface and getting familiar with the controls and the numerous settings the radio GUI had. It must have been after about 4 or 5 hours playing that I went

through the FT-817 manual, it was worth the read and time spent playing around. I became confident and started the PSK31 interface via the Commander interface.
I remember changing to a data frequency and also a setting to PSK31, I typed in “cq cq cq m6mbm cq cq" and sent it. I later realised that using the CAT lead was only enough to receive data to and from the commander graphical user interface(GUI), and that an additional data lead was needed to send data from the laptop to the radio

My QRP experience so far had been while using silent key Frank, G4CPT's FM 2m transceiver. A TR2300 trio with 5w output,10w if you use the power amp he made with it and a slim Jim antenna
The furthest QSO was with Steve M0GXN based in Chislehurst, Kent. Since I had been using Franks

rig I suppose going on the best part of a year, I had found my local area to be very quiet, every now and then the local amateur clubs, Barking & Havering and LEFARS would have nets and I took part any time I was on air and heard them. Unfortunately around this time while using the FT-817 two metres had been exceptionally quiet. I tried putting out a cq call a few times without response so didn’t know how I sounded. At this stage I couldn't try the SSB frequencies on HF as I knew these were really dependant on having suitable antennas which I hadn't got round to experimenting with yet, however the manual suggested that the FT-817 rubber duck antenna is designed to cope.

So I gave it a bash, scanning the bands manually and also using the built in scanner. I thought I had heard very faint morse or a sound of that nature, when I tried to lock in on any signal it eventually started to sound like a data noise. I switched to one of the data programs I had installed, first I tried Commanders PSK31 and didn’t see any data being decoded on screen.
I went on-line and watched a video on you tube about PSK31 to see what it was I may have been doing wrong. My hunch was correct, even though I had a CAT lead this only control’s the PTT and the controls to the rig. I still needed to interface to the PC sound card and the DATA port on the rig.


The video made by Randy K7AGE was very helpful and got me up and running without going to the expense of having to purchase a data lead. He shows how to set up another application called DigiPan which can be found on  this site

All that is needed is a pc microphone plugged into the laptop and you place it on top of the FT-817 near the speaker. Once launched the DigiPan software was very easy to get to grips with, especially after the very informative explanation given by K7AGE.
I was soon starting to see garbage coming in on the interface It was starting to look good for success with hearing a few QSO’s with PSK31


Another promising program that I never really got much response from was the weak signal propagation reporter (WSPR) pronounced whisper. The program is all about sending & receiving signals that are barely audible, and I started to think that you use it like a beacon, in that you just let the program run all the time

or​ just when you are operating to send out signals and to listen for signals. You can find out who is operating near you through this website. If you become a member you can use the site chat room to arrange schedules with other operators and perhaps do antenna checks.

Unfortunately it wasn’t very rewarding however I really believed this would prove very fruitful once I had a good antenna system in place. I couldn't wait to have a go at the club.....

Well as I had hoped the on air session at the club proved very fruitful indeed.
Peter, G4KSE and I had a scheduled QSO with the person with whom I had my first ever HF QSO with. His name is Peter, G4IUV and is based up in Norfolk. We made contact on 80 metres but only just,  conditions were exceptionally bad. In fact another station 2E0EKG Nigel based in Chichester could hear us and Nigel kindly acted as a relay.

We put the HF rig away and got the FT-817 out and set-up the laptop and radio. I gave Pete a quick run through of the controls on the actual rig and then started the Commander interface for him to see.
It was getting late it was already 11.40pm so I quickly selected one of the PSK31 frequencies stored on commander, 7MHz and straight away we had strong data type activity.
I started the PSK31 interface through commander and to my great joy we actually started to see
"CQ CQ CQ de" coming up on the screen. YES, I was over the moon. Peter and I were both tired so we decided to call it a night. Operations to be continued the next day.

Pete kindly loaned me his MFJ ATU. I intended to rig up a long wire to see what I could pick up on HF.

73’s for now

Michael M6MBM


Radio Problems Of a Serious Nature

By G-MWEZ aka M5AJK.

Readers of the January edition of Spurious will remember my difficulties in contacting the Distress and Diversion cell, the AA of the Sky, during my flight between Northern Ireland and the Mull of Kintyre during June 2012.  Fortunately it was a ‘Practice Pan’ and not a ‘Mayday’, so the failure of my radio to transmit effectively was of no real concern.  However I might not be so lucky next time, so action was needed.

My first thought was that the coaxial cable had become damaged due to some problem such as water ingress and a new cable would be the answer.  It was certainly not working as expected.  Although I could get a signal report of strength 5 from pilots when we were on the ground at my airfield, this did not translate to 5 when airborne, at greater distances of several hundreds of yards and more. 

My next visit to the airfield was to prepare G-MWEZ, my Shadow microlight, for a flight up to Derbyshire with a passenger. Yes, I was taking Clive, G8VZD to Calton Moor airfield near to Ashbourne so that he could pick up my mother’s car which he had bravely bought, sight unseen, before he headed further northwards to spend a few days with friends walking the dales and peaks.  I couldn’t go without ensuring that I could call up should we get into difficulties. 

The Distress and Diversion cell, known as D&D, is the name given to the radio service that monitors the frequency 121.5MHz, the emergency frequency.  This frequency is used not just for dire emergencies such as structural failure of the airframe, or fire in the air, but also in the event of being unsure of position.  If I were to wander off course I might fly into a zone reserved for airliners for example. The result could be an airprox (near collision) or worse, or it could be that the airliners are diverted away from me. The cost of diverting a large airliner is about £100 per minute, so I want to avoid that cost!

If uncertain of position a pilot may call up D&D and ask for a position fix. Within moments D&D will have triangulated the aircraft position and given a bearing to or from an object or airfield so that safe flight may be resumed. If I had wandered into reserved airspace they would also give guidance to depart that space by the most expeditious route. A very useful service!
Back to the aircraft…  

Peter, G4KSE and I spent a couple of days at the airfield fitting new fuel tanks to G-MWEZ (known affectionately by pilots around the country as WEZ).  During this time we also fixed a few other problems that became apparent, such as welding up a split in the exhaust and changing some rubber fuel pipes that

were becoming perished. I also took a look at the radio coax and radio installation. The antenna is a quarter wave whip which is mounted above the pilot on top of the fuselage. It can be seen in front of the central wing section in the picture. The fuselage covering is just 1mm thick plywood which doesn’t form any sort of ground plane, so it is lined internally with a strip of cooking foil glued in place, and which is very effective. The coax enters the fitting through the underside of the whip and the core is connected to the whip by a grub screw. The braid is turned back along the outside of the sheath and when the coax is pushed into the fitting this makes a tight contact with the earth side.  Simple but effective – usually.

I examined this connection of coax to braid. Not with a microscope or magnifying glass, but using the robust technique of giving it a twist and a pull.  It didn’t seem quite right – I think the technical term may be that it had become too wiggly! Perhaps here was the problem. So I tried to disconnect the antenna from the body of the aircraft. There is a hexagonal shape to the body so I gave it a twist and the fitting loosened.  However, for some reason, unknown to me, it wouldn’t unscrew entirely. In fact it left the fitting loose on top of the aircraft, with me unable to take it off and unable to screw it back down. Not good.

After much prying at it, I realised that it really wasn’t going to come away, so I then resorted to trying to get it back on. This wasn’t easy either, but eventually a thread caught on the nut and it tightened down. With much relief I then undid the grub screw that holds the

inner conductor of the coax and pulled the coax free. Now to re-fit it.

In the usual fashion I determined the length of inner conductor that should be bared of insulant and cut this away. I then decided how much of the insulant should show and I cut back the outer insulant. The braid was then turned back over this sheathing and the whole was pushed back into the antenna base. The braid was a very snug fit on the antenna so it was clear that a good connection was made. I then tightened the grub screw to attach the inner conductor to the antenna whip and the job was done. It looked much better. But, as Marconi would have said, the proof of the pudding is in the transmitting. 

A pilot has to do three landings in the three months prior to carrying a passenger, so as I hadn’t flown since last June I had to carry out this procedure. It was the day of the flight to Derbyshire so I reserved the test until I was sitting in the aircraft with the engine running to provide power to the
radio. I made my call… ‘Plaistows traffic, G-MWEZ, radio check, please.’  Nothing heard!  I tried again with the same result. Things were looking worse than before. Clearly no-one could hear me.
So I called Peter over and asked him to have a word with the pilot of one of the aircraft that were at the airfield.  This he did and after a bit of fumbling by the other pilot to get the frequency right I heard his response. ‘Echo Zulu, you are signal strength 5’.  Relieved I replied in the usual fashion. ‘Thank you.  You are strength 5 also.’ And so I set off to complete my three landings.

The farmer and owner of the airfield was busy cutting the grass of the runways so I waited for him to clear the runway before entering and lining up for take-off.  My first circuit was uneventful and I called for a landing on runway 33 before quickly correcting to the more into wind but shorter runway, 30. I saw the tractor clear the runway as I turned for final approach and I made a touch and go, returning to the circuit for a second touch and go, followed by a full stop. With my three landings complete I was entitled to carry a passenger. It seemed clear to me that the tractor driver, who has a radio in his cab, had heard me and

cleared the runways for my approach each time.  No problems with my radio then. That’s all good then.

Now it was time for Clive to squeeze himself into the rear cockpit ready for the flight.  He just managed it and settled down to two and a half hours of cramped conditions. The aircraft is definitely a pilot’s dream but might be considered a passenger’s nightmare! Once again I made the radio call anyone for a response but got nothing back. I decided that they were all too busy to be listening, so I called my intentions to take off and away we went.

The flight was interesting – we followed the M1 then A5 and at 1500 feet we had a good view of the Silverstone race track. The flight was a bit bumpy due to turbulence so we flew a little higher in smoother air at 4500 feet. As we approached Hinkley, Clive noticed that it was getting colder as the sun hid behind the clouds, so it was prudent to come down to around 1000 feet where the air temperature would be 7 degrees warmer. It was but the turbulence returned and more pronounced. Not to Clive’s liking, but it was only about 20 minutes and we were in the circuit above Calton Moor.

At many airfields around the country where there is no allocated ground based radio, the frequency used by pilots is 135.475MHz, known as Safetycom. This is the case at Calton Moor, so the procedure is to call ‘blind’ using the call ‘Calton Moor traffic’. I called on my approach to advise that I would be landing on runway 24. I then called again to advise that I was down wind for runway 24, and finally I called ‘Final 24’. The radio was quiet in response. Perhaps there was no-one flying. Or is there still a fault? 

I think I’ll check the antenna more thoroughly before Fly-UK.


How Long Do My Batteries Last?
A Quick Guide


One problem that comes up frequently in amateur radio is the actual practical life of batteries or put it another way how long you can actually use them before they become ineffective. Batteries and there construction are actually quite complex. However that does not stop the radio amateur having a stab at the calculations.

With lead acid batteries (car type) the ten hour rate is normally used. What does this mean in practice? Well if the battery is rated at 100 amp hours, it could in theory deliver ten amps for ten hours.
In practice batteries DO deteriorate for various reasons, incorrect charging rate, storage, lack of maintenance, temperature, etc which can all adversely affect their capacity if not done correctly or at the wrong level. One way of finding the actual capacity is the load test, it however requires equipment normally found in commercial premises. It will also depend upon the type of load, for example when using a SSB transceiver the waffle to listen ratio (good technical term that). The actual use may well exceed ten hours as it is not a constant continuous load. It is also worth mentioning that

some manufacturers use the twenty hour rate instead, so the capacity of the battery is simply divided by twenty. So it is worth while actually reading the manufactures instructions in the first instance.

But how can we work out how long the household batteries shown in the picture will last? Again this involves finding out the capacity of the batteries from the manufactures specification and divide by the load giving the time in hours. Some conservative values of alkaline manganese batteries were obtained from the internet as shown in the table below:

Battery type  Capacity mAh Typical load mA  Hours  use
D                    12,000                200                       60
C                     6,000                 100                       60
AA                   2,000                  50                        40
AAA                 1,000                 10                        100
PP3 (9v)            500                  15                         33
6V lantern       11,000               300                        36




It’s then straightforward to change to load values say on a spreadsheet and see how the numbers pan out. If you look at AA batteries and insert the load of a digital camera instead it is easy to see why they do not last very long !

For those that would like to read into the subject even more I would recommend having a look at the website below. It gives the load charts, cut off voltage, characteristics etc of Duracell batteries. There’s plenty of technical info for the radio amateur to get their teeth into.

Leslie  G0CIB


Leslie G0CIB has shown an interest in taking part in the Practical Wireless 144MHz QRP competition to be held 9th June. Weather permitting he and Michael, M6MBM are planning to operate from Pole Hill

If anyone is interested in participating in any special events or contests please make this known at the Friday evening meetings.

Why not organise a team. Operation from the Silverthorn shack is available at most times or go portable. The Club equipment is usually available if needed.
Is anyone up for one of the more unusual contests this year?
If so please contact me to see if we can get a team together.




Diary Dates

Club Events This list supersedes all previous ones.  Please note these events are subject to change and other events will be added as they are organised.

March - Club moves to 54 Friday Hill

Future events in 2013

PW QRP 144MHz                  9th June 2013
VHF National Field day          6/7th July 2013
Silverthorn Club Camp          26th July 2013           Opening 12 midday until 29th July 2013 
Jamboree on the Air             19/20th Oct 2013
Annual General Meeting       25th Oct 2013  8.00pm.

Local Rallies 2013

Don’t miss these rallies…                  Check details with the organiser before making the journey

NATIONAL HAMFEST - RSGB in association with the Lincoln Short Wave Club.
Newark and Notts Show ground, Newark.


Near Milton Keynes.

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