Saturday, 8 February 2020

Ham Radio-fascinating hobby

Ham Radio-fascinating hobby

Ham Radio-fascinating hobby, how I started in the fascinating World of Ham radio and how it leads me into the Telecommunications Industry, where I worked as an Engineer.

Ham Radio - How Did I Start in This Fascinating Hobby?


It all started when I received a book called "wires bulbs and batteries." It was Christmas following my sixth birthday. I believe it was due to the fact that my parents had noticed their torch had been taken apart, and the components rewired together.

Ham Radio - How Did I Start in This Fascinating Hobby?

After studying the circuit diagram in the book on batteries and bulbs it seemed obvious that I was keen to explore electricity and how circuits worked together when a switch was activated and the bulb lit. I soon explored the school library and found a book called how to build a crystal set. These books are still available on auction websites at reasonable prices; I would buy one they still hold great information even today, fifty years on.

Ham Radio - How Did I Start in This Fascinating Hobby?

May I suggest that you explore the secondhand market for a general coverage receiver? Listening to the Short Wave spectrum will give you a good grounding in what Ham Radio has to offer. It is better to buy a secondhand receiver from a reputable dealer, secondhand radios keep their value if you decide to sell it on if the radio is not for you.

Ham Radio - How Did I Start in This Fascinating Hobby?


For the more adventurous explorer, a radio kit is a good introduction to Ham Radio. A kit comes with all the components and a drilled circuit board which removes the time from having to source components separately from radio suppliers.

Ham Radio - How Did I Start in This Fascinating Hobby?


If you decide to buy a Short Wave receiver, make sure it has the capability of receiving Frequency Modulation or F.M. My first commercial the receiver was used as a driver for a frequency converter. Using the ten-meter band as an Intermediate Frequency and the converter I could tune into transmissions on the V.H.F. Ham Radio allocation on 144 Megahertz.

Ham Radio - How Did I Start in This Fascinating Hobby?


Another excellent way to develop your interest in Ham Radio is to buy an ex Private Mobile Radio Transceiver, the type used by taxi companies and Utility services. Some of these transceivers can be easily converted to Ham Radio bands at a fraction of the cost of commercially designed equipment. There are many websites showing you how to do this.

Ham Radio - How Did I Start in This Fascinating Hobby?


In my opinion, building either a receiver or modifying a piece of commercial equipment, have many advantages for the newcomer to Ham Radio. 

The education is worth its weight in gold and you can go on to other modifications, including making fixed crystal-controlled receivers and transceivers into variable frequency rigs by building a variable frequency oscillator. 

There are plenty of instructions on the internet for the keen and practical Radio Ham.

Ham Radio-John G4YDM

Ham Radio-John G4YDM

Ham Radio-John G4YDM

Ham Radio-John G4YDM.  Thank you for your continued complimentary comments about my artwork-Ham Radio is my other interest-I,m a Radio Engineer by profession.

Ham Radio – What Is a Balun and How to Make One Cheaply

A Balun is a transformer which allows coaxial cable, which is an unbalanced lead to be connected to a balanced load, for example, a resonant aerial.

The 1:1 balun is often called a choke balun, it works by eliminating Radio Frequency currents flowing on the outside of your coaxial cable, this is important because it prevents the pattern of the dipole becoming distorted and prevents the braid of the coaxial cable radiating.

Connecting coax to your resonant dipole can be configured in a V shape or in a sloping fashion, however, serious power loss and feeder radiation can occur without the use of a balun transformer. No one wants to induce Radio Frequency currents into Television receivers or Broadcast equipment as it may result in disputes with neighbors and could possibly lead to your station having to close down. 

Try to keep the center of your aerial away from buildings as it may induce Radio currents into the mains wiring.

Building a choke is not difficult all you need is some plastic pipe available from many Do It Yourself outlets and warehouses. I use a length of about 1 foot of plastic pipe and 21 feet of coaxial cable, the length of the pipe and diameter is chosen because it works well if using R-G-5-8 coax the ends of the pipe can be sealed after placing a SO-239 connector for your coaxial lead. I use two bolts and solder tags at the other end of the pipe to connect the ends of the dipole to the choke.

When wrapping your coax around the pipe don’t use too much force as it may damage the inner braid and space the turns away from each other by a millimeter or two. R-G-2-1-3 coax around 21 feet used with the 5-inch pipe will handle 400 watts pf power. 

Wire ties can be used to hold the turns together along the length of the pipe. Using these measurements your choke will cover all of the ham radio bands from 1.8 Megahertz through to 28 Megahertz and will keep the radiation pattern.

Using a dummy load connected to the choke and transmitting 100 watts from my transmitter indicated S.W.R. readings of around 1.5 to 1 at 3.5 Megahertz when testing 28 Megahertz the S.W.R. reading came down to 1.1 to 1 which is an excellent match. 

Using the choke as it should be at the feed point of a dipole cut for 40 meters gives an S.W.R. reading of 1.2 to 1. The highest reading was 1.5 to 1 when using 18 Megahertz but the rest of the High-frequency bands gave me very acceptable matching.


Ham Radio-John G4YDM

Ham Radio Pages

Ham Radio-aerials

Ham Radio-aerials

Ham Radio - A Wide Band Aerial for VHF or UHF Bands

Ham Radio-aerials, I was recently asked to help out a newly licensed radio ham with his VHF & UHF aerial system, he was finding that a Disc-cone aerial which he had been using for a number of years as a Short Wave listener was not doing a good enough job of transmitting his VHF l and U.H.F. signal. 

Here is a suggestion of how you can improve your Ham Radio aerials.

The Disc-cone is a well-known wideband, Ham Radio-aerial, used by many people who enjoy scanning the VHF and UHF part of the Radio Spectrum for commercial traffic and Ham radio transmissions.
The Disc-cone works well if you are nearby to radio masts that repeat the broadcasts from commercial or Ham Radio bands but they vary in their bandwidth and sometimes fail to give adequate matching at ham allocations.

I have seen Disc-cone S.W.R. (Standing Wave Ratio) readings at 5 to one on two meters or 144 Megahertz, this can severely impair both your output signal and the received signal.

Most Ham radio Transceivers are designed with 50-ohm output connections using SO-239 sockets, these allow easy connection to the coaxial cable used by many operators as their means of feeding their transceiver power into an aerial. 

A 5 to one impedance match at VHF is not desirable; it indicates the load you are transmitting into is either 5 times 50 or 50 divided by 5. 250 or 10 ohms will not deliver all of your power into your aerial and conversely it will not gather the voltage required by your receiver for optimum efficiency. Radio transmissions need to be correctly matched, maximum transfer of power only happens when the feed line sees the correct load, in our example 50 ohms.

Here is a simple aerial, which can be built inexpensively from a length of the square wooden post. The aerial will transfer power correctly and at the right load, I.E. 50 ohms. Using this aerial I have seen my signal meter improve on two-meter transmissions at 144 Megahertz and the rest of the frequency bands it was designed for.

Wooden posts are available in different lengths, from four meters and above down to 2.5 meters, these posts are available from most high street to Do It Yourself outlets and are not too expensive to buy. Being square they have four sides; these sides are used to hold a dipole for the bands you choose to operate on. 

A three-meter length of post comfortably holds `four Radio ham bands, namely six meters, four meters, two meters, and seventy centimeters. These bands work out at 50 Megahertz, 70 Megahertz, 144 Megahertz, and 432 Megahertz respectively.

The aerial is very similar to a nest of dipoles that are commonly used by radio Hams for use on the H.F. part of the Radio spectrum. This allocation is between 1.8 Megahertz and 30 Megahertz.

Using the formulae to calculate the length of a dipole, I.E. 468 feet, divide the lowest frequency into this number. In our case, we are going to use 50 Megahertz. The six-meter band or 50 Megahertz works out about at about 9.36 feet for our dipole, depending on what part of the band you wish to use, this length is the longest that can be accommodated on a three-meter length of the wooden post.

Using the remaining three faces of the wooden post, attach the other three dipoles which you have calculated from the above formulae. Attach you 50-ohm coax to the center of the four dipoles weatherproof using duct tape, the inner or Braid of the coax is attached to the lower part of the four dipoles and the inner is attached to the upper part. Both the inner and Braid parts of the coaxial cable are secured with an additional piece of wire. 

If you intend to use this aerial in the horizontal plane, make sure that the feeder falls away from the post at 90 degrees. If you intend to use the aerial in a vertical position and additional piece of wood is attached near to the feed point at ninety degrees, running the coax parallel with the dipoles makes tuning very difficult because of the dipole elements.

The aerial is completed by trimming the highest frequency for the lowest S.W.R. reading, in our case, this will be 432 Megahertz. Mounting the post on brackets on the side of your house as high as possible will give you the best performance, however, if your loft or attic space is high enough you can mount it indoors. 

Turn the aerial through 90 degrees for horizontal polarization, used mainly for S.S.B. and C.W. transmissions. Complete the aerial by winding about nine coils of the coax cable and place it near to the feed point; this choke prevents the braid from radiating your signal.

Ham Radio-John G4YDM

Ham Radio-SDR Receiver

Ham Radio-SDR Receiver

Ham Radio and the RTL SDR Receiver

Ham Radio-SDR Receiver.  Did you know that you can listen to Ham Radio via a simple dongle plugged into your computers USB drive?

The device is called an R.T.L.-S.D.R. receiver, it uses software that allows you to listen to Ham Radio and many other radio transmissions including Police, Fire and Ambulance transmissions. The receiver is based on the R.T.L.2832-U chip-set and often called the D.V.B.-T TV tuner

These cheap dongle receivers cost as little as 8 pounds and turn your computer into a general coverage receiver. With appropriate software, you can store and scan frequencies just like scanners costing many hundreds of pounds

Software-defined dongle receivers on the market including the Air spy and S.D.R.-PLAY costing around $199 and £149 respectively and there are other higher priced units including the Hack-RF costing $300 and the Blade-RF which currently sells for $650 these units actually transmit as well as receive.

Software-defined radio receivers replace traditional radio receivers, which were constructed with radio components including modulators and amplifiers, these hardware components are now replaced with software. Modern computers using easy to download and install programs do the work of all the processing needed to de-modulate signals and turn your computer into a modern radio receiver.

S.D.R. radio offers the opportunity to de-modulate ham radio transmissions across a wide part of the radio spectrum. High-frequency bands are covered and you have the benefit of listening to a full range of transmission modes including single side-band, amplitude modulation, and a constant wave or C.W. many allow F.M. reception too.

S.D.R. radio allows hobbyists to monitor aircraft control conversations on both short wave and V.H.F. band. You can also track aircraft using ADS-B (Automatic Dependent Surveillance-Broadcast) which plots the aircraft position on a local map. A.C.A.R.S. is also catered for making S.D.R. receivers a very beneficial tool for the ham radio hobbyist.

Programs are available which allow the reception of digital radio mono-dial this form of broadcasting is used by international broadcast stations, It provides superior audio quality compared to A.M. signals by utilizing digital audio encoding.

One of the most interesting applications to use with your S.D.R. radio is receiving N.O.A.A. weather pictures, there are many multiple satellites pass every day, N.O.A.A. weather satellites broadcast Automatic Picture transmissions and these broadcasts contain live weather images of your area.

You can de-modulate N.O.A.A. pictures with a good outside aerial and a program called S.D.R.-Sharp and an additional decoding program, these images can be seen several times a day.

There are many more programs to use with S.D.R. radio, D-star and D.M.R. together with fusion transmissions can be de-modulated. A great benefit you have using these simple radio receivers is that most of the programs are completely free to download and use.

Ham Radio-SDR Receiver

Ham Radio-Mistakes

Ham Radio-Mistakes

Click the links below, these are articles which I have written to help new people understand aspects of Ham Radio.

Ham Radio-Mistakes

 Ham Radio-Mistakes.  I have compiled a list of mistakes that most new radio hams make when they launch themselves into our fascinating hobby, but don't worry too much we all make mistakes.

New transceivers are packed full with many features and benefits, some benefit certain area's and others just make life more complex, the majority of new hams buy a two-meter transceiver either a mobile or handheld to get onto the local repeater, your problems start when you try to upload too many frequencies onto your handheld, after all, there are usually just a couple of VHF repeaters in your vicinity and a number on UHF, trying to load up the transceiver with hundreds is a big mistake and will lead to confusion and sadly disappointment, but do not let these teething problems deter you from learning.

Access tones are often problematic to the new radio Ham, C.T.C.S.S. tones were introduced a number of years ago to prevent operators accessing repeaters in other parts of the country during good lift conditions. Take your time and find out what your local repeater tone is. C.T.C.S.S. adds and sub-audible tone to your transmission to open the repeater and some need it on receive. C.T.C.S.S. stands for the Constant Tone Coded Squelch System.

Older repeaters also use a 1750-HZ tone burst to access the repeater, check through your hand-held manual and research your local repeater to see which C.T.C.S.S. tone you need and find out if 1750Hz is required, these simple instructions will allow you to quickly access your local network and allow you to engage in your first contacts. Repeaters use two frequencies an input and output, make sure to learn what the shift is, on two meters its -600KHZ below the output and UHF is often 1.6 Megahertz higher than the output frequency.

Find out where the microphone is in your handheld transceiver, speaking too loud or not loud enough distorts your signal, don't worry though just ask a fellow radio ham what your audio sounds like and adjust settings accordingly, speak a couple of inches away from the microphone if using a mobile rig or mobile transceiver. I find that a separate speaker and microphone which simply plugs into the handheld is a great asset to your operating, the audio quality on receive and transmit is often much better.

Don't expect too much from your handheld transceiver, they are designed as a pocket set and often arrive with a rubber duck aerial or helically would stub, checking these over the years on a sophisticated sweep generators I have found many to be less than ideal on two meters, due to the extra length required, UHF or seventy centimeters seem to be where most rubber duck aerials are optimized, however better hand-held aerials are available to solve this problem.

I came into the hobby after many years spent as a short wave listener and constructor. Listening is a great benefit to the new radio Ham, you find a lot by listening. Find out who the best operators in your area are, take particular attention to how they conduct themselves. Listening for local nets which tend to operate on specific days at precise times will also help your understanding, join in and make new friends and above all ask questions, in my early days I never got into a situation where I struggled for an answer to a radio problem, get onto the air it will help your confidence.

Scanning the repeaters in your area will indicate when activity peaks, don't just sit and listen all the time put a call out on the local repeater ask for a signal report or audio report and do the same if you hear people calling, go back to them and before long you will be making regular contacts and gaining confidence.

Ham Radio Articles

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Ham Radio - John G4YDM

Ham Radio enthusiast-What to do in Washington Tyne Wear

Ham Radio enthusiast-What to do in Washington Tyne Wear 

Ham Radio enthusiast-What to do in Washington Tyne Wear.   Many readers have continued to comment and praise my artwork, everybody likes the Queen mum and Princess Diana, however, my portraits in oil featuring Alan Shearer and Niall Quinn, football players from Newcastle & Sunderland football clubs get the majority of my thumbs up comments and suggestions.

All of my work is created in oil on linen canvas, oil, in my opinion, is the best medium to use in art, nothing beats the vivid colors and deep tones achievable when using oil as a medium, please enquire I am available for commissions, simply use the contact form on my home page.

Readers of my website have requested information on what to do in Washington Tyne wear, attached below are some links to help you with your visitor plan.

WWT Washington Wetland Centre

Washington Old Hall

Arts Centre Washington

Washington Millennium Centre

Ham Radio enthusiast-What to do in Washington Tyne Wear 

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