G4IYK

G4IYK This is where I park my Radio Stuff. You'll see its quite small. I hope it will grow.

like many people I take pleasure from skills and learning and supporting others.

The Clansman DipoleBelow is a Clansman dipole.  It comprises 2 antenna (Kevlar wire) elements graduated in meters, by ad...
08/09/2024

The Clansman Dipole

Below is a Clansman dipole. It comprises 2 antenna (Kevlar wire) elements graduated in meters, by adding markers at various spacings from 2 to 30 Mhz. The wire is wrapped onto double reels. The markers are designed to make it easy to set up in the dark with different markers at 1, 5 and 10M intervals. The reels also hold about 100 M of very nice string*. There is a dipole centre junction, (not a balun). The kit also comes with 30m of 50 Ohm Coax and a four wire counterpoise for improving ground reflection when operating the antenna against the earth.

This type of kit has traditionally been used by the military to create a number of balanced and unbalanced antenna for portable use. It accompanies the Clansman HF radio sets as standard and the radios come with a laminated chart detailing the required length for end fed and dipole antenna.

The chart simplifies the job of calculating the length of wire needed for any particular frequency.

In use, to erect the antenna, the operator reels out enough string to throw the whole wire element over an object such as a tree, and then ties the end of the string off. The required length of wire is then reeled off, fastening the appropriate length marker to the reel. This is repeated for the other side of the antenna and then each side is connected to the centre junction, and the coax before hauling it taught to form a horizontal, vee shaped or inverted vee dipole.

The inverted vee antenna is a simple and effective method of achieving high angle radiation for omni directional use and good in hilly countryside or woods. This is because the Signal is bounced between the f2 layer of the ionosphere and earth , in all directions, for between 0 and 900 Km.

For longer distances, mounting the Clansman dipole antenna horizontally will produce a bidirectional radiation pattern and if the height is set at a quarter wavelength it will achieve distances in excess of 1000km. The military user is supplied with additional equipment to aid construction.

There are a number of electrical issues that have been designed out of the clansman radios, to create this simple effective tool kit. The surplus wire affects the electrical length and the antenna lacks a balun, although to prevent interference from nearby transmitters the set is provided with a tunable filter instead. In amateur radio such an antenna would be cut to length and trimmed, then a reel added to make it portable and reusable. Several antennas would be needed to cover various bands and traps or switches could be added.

Amateur radio enthusiasts have different needs and might find difficulty in practice to bring the Standing Wave Ratio to an acceptable level. Using the published chart produces an antenna that is too long and therefore unmatched to the 50 Ohm output of the set. One way to overcome this is to use an Antenna Matching Unit (AMU or ATU) to Tune the antenna. As I don't yet have an ATU in my mobile setup, this time out I used an antenna analyser before hooking the antenna up to the radio, simply reeling in the surplus antenna wire until the analyser showed the lowest SWR.

Using this setup, I worked Peter, G3RE in Poole, Derek G3XWD in Staffs and Mike G4ICC in Leicester using a FT891 using 100Watts. Signals were conversation quality.

* very nice because it has been specially selected to slip smoothly across most surfaces, which decomplicates setting up and taking down the antenna.

The antenna reels come up on Ebay from time to time.

11/10/2022

steve

People are rebelling, as a Tesco employee of nearly 40 years I find myself tending to agree with this chap@. Sorry

5/8ths on 10m and 10Watts out.  Bring on the Sunspots.
06/07/2022

5/8ths on 10m and 10Watts out. Bring on the Sunspots.

12/06/2022

Nice to be able to hear and work Sardinia this morning on 6m. Only one glitch. RF stopped the PC. Need more ferrite :)

11/01/2022
The view from 2E0OOM this morning.
27/05/2021

The view from 2E0OOM this morning.

15/04/2021
https://www.ebay.co.uk/itm/LCD-Digital-Electromagnetic-Radiation-Detector-EMF-Meter-Field-Dosimeter-Tester/363287781535?...
13/03/2021

https://www.ebay.co.uk/itm/LCD-Digital-Electromagnetic-Radiation-Detector-EMF-Meter-Field-Dosimeter-Tester/363287781535?_trkparms=aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D20201210111314%26meid%3Dbf86e15a642841a0b5fa1164b0f62760%26pid%3D101195%26rk%3D6%26rkt%3D12%26mehot%3Dpf%26sd%3D353417409113%26itm%3D363287781535%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv9PairwiseUnbiasedWeb%26brand%3DUnbranded&_trksid=p2047675.c101195.m1851

Interesting market springing up for EMF Testing. This one says its a dosimeter and has an alarm when safe levels are exceeded. I can just imagine such a device in the hands of a neighbour.

Feature: 1. One Machine for Two Purposes: it can measure electric field (1v/m~1999 V/m) and magnetic field radiation (0.01μt~99.99μt) at the same time. 2. Clear Display: The built-in electromagnetic radiation sensor can display the radiation value on the clear LCD digital disp...

A days work with Mike 2E0OOM to get this GAP Titan pointing skyward.
09/03/2020

A days work with Mike 2E0OOM to get this GAP Titan pointing skyward.

19/02/2019

Having now decided to change broadband service providers, I had a call from BT today to ask why I was leaving. The YL at the other end was quite enthusiastic up to the point I said of course the other reason I am leaving is because BT Openreach can't apply the filters to their VDSL Router installations and it is having a devastating impact on my hobby which is listening to medium wave and shortwave broadcasts and amateur radio. "I haven't heard that one before" she said. I said that doesn't surprise me. I am going with Virgin, and if I can persuade all the other neighbours to do so, then I would. End of conversation.

On the Royal Engineers 80m net this morning.  Listening to Hackgreen Web SDR because my own receivers are jammed with lo...
02/02/2019

On the Royal Engineers 80m net this morning. Listening to Hackgreen Web SDR because my own receivers are jammed with local noise thanks to BT Openreach et al😕😕. ( Planning Policy and Neighbour Relations Support Group - UK Amateur Radio How can they do this?)

Without Web SDR I would have been forced off the air years ago. I am particulalry grateful to hackgreensdr.org. It's not without problems though. If your broadband drops out or is intermittent it's very difficult to keep up with a conversation if you are using a browser alone - keeping the radio and the PC on the same frequency can be a problem.

This job has been made ultimately easier by CAT Sync https://catsyncsdr.wordpress.com/

This amazing piece of software allows the WEB SDR to be controlled from the radio. Catsync keeps the WEB SDR (on the PC) on the same frequency as the local radio by synchronising with it. Also the photo shows the favourites list which enables you to flick between SDR Sites. Before going on net this Morning I tested signals from a few sites.👍 including the Secret Nuclear Bunker in Essex and locally in london to see how my own signals were being received.

Full Duplex allows you to hear your own signals coming back if conditions are right which is an added bonus to SDR. Theres nothing to dislike about this and as it costs less than £10 its well worth it. Please also consider a donation to the Web SDR Sites you use because as far as I can see these guys are saving HF Amateur Radio.

December 2nd. RSGB 2 Meter contest with Invicta Contest Group - My first time in a Radio Contest - learnt lots :)
03/12/2018

December 2nd. RSGB 2 Meter contest with Invicta Contest Group - My first time in a Radio Contest - learnt lots :)

19/11/2018

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Amateur Radio and Me

In 1979 I was lucky to be mates with a radio amateur called Gordon, G3WOV who taught me the whole syllabus and encouraged me to take the exam and the morse test. Some of this was also part of the Army Radio Operators Syllabus and as that was where I was almost fifty years ago, that’s when the party started. Since then I have operated a licensed Amateur Radio Station in UK, Germany and Zimbabwe which is why I put the commemorative QSL card in as the cover photo.