About me ...
By Fred Johnson ZL2AMJ
Summary:
Early Days The Amateur Radio Examination
My Early Radio Interests Treasure Trove
Forestry Communications My First Transmitting Antenna
My First Receivers My First Operations
Signals Operating Portable
My age is not secret. I was born on 17 February 1932 at Riverhead Forest, just north of Auckland, New Zealand. I have often wondered why anyone would want to keep their age secret! My father was the forester in charge of the forest. It was the time of the "great depression" and there were many work parties around the forest working on projects to give work to men who would have otherwise been unemployed. I have many memories of this time and its circumstances.
My father was a radio amateur. Joe was licensed as 2GA in 1925. As the system changed, he changed to Z2GA in 1926, to OZ2GA in 1927 and to ZL2GA in 1929. He later held the callsigns ZL1CX, ZL4FC, ZL2AHD and ZL2GA (again) at various times as we moved around the country. He died in 1977.
Joe was a Foundation Member and one of the six NZART Vice-Presidents at the time of its founding in 1926. You can read about him in the history book "Ham Shacks, Brass Pounders & Rag Chewers, A History of Amateur Radio in New Zealand" 1977, by Ian Dougherty, published by NZART. Detail about this publication is at: http://www.nzart.org.nz/nzart/history/history.html Back to Summary
So I was born into Amateur Radio. My father had some boxes of radio gear. These were frequently emptied by me and the contents closely examined. There were many large variable capacitors - meshed plates that opened and shut. What possible use could they be? I didn't know what they were called, and could not envisage their purpose. There were meters too - round things with a glass front and a wobbly pointer inside.
Sometime around 1936 we moved to Invercargill. At times my father was away from home for a week or so inspecting forests. On page 211 of the history book is a picture of my father with a portable station that he had constructed many years earlier. Dad arrived home from one trip to find that in his absence I had started to dismantle it! He wasn't very pleased! How can you find out what's inside and how it works if you don't dismantle it?
Dad had stacks of radio books - QSTs of many years, ARRL Handbooks and The Radio Handbook (Jones) with pictures of transmitters and receivers, I regarded these in awe. They were well thumbed by me! There were "Lamphouse Annuals" too, published by "The Electric Lamphouse" of Manners Street in Wellington. These showed pictures and diagrams of simple receivers, simple "crystal sets"!
I can remember a magazine arriving in the mail addressed to my father - it was called "Break-In". Back to Summary
In 1940 we moved to the Headquarters of Kaingaroa Forest, some 32 miles from Rotorua where my father was second-in-command of the forest. It was wartime, the Second World War was raging.
The NZ Forest Service introduced radio to assist with the management of the forest. The main station was ZLGA at the Headquarters with other stations at various outposts. The callsign ZLGA had an association fascination for my father! All the gear was made by "Collier and Beale". One of the reasons that my father was transferred from Invercargill to Kaingaroa Forest was because his background in radio would be useful for the introduction of radio to forest management.
The frequency in use was 2760 kHz. All equipment was amplitude-modulated phone. There was a daily "sked" to test all the stations in the network. ZLGB was at Waimahia at the southern end of the forest. ZLGC at the Headquarters of the Conservancy in Rotorua. ZLGD was a portable station, powered by a 12-volt battery, carried around on the back of a truck. ZLGE and ZLGF were portables. These were a small grey box, with a telephone handset with press-to-talk switch on the handpiece, powered by a Number-6 cell and 45-volt batteries.
ZLGA, the base station, was installed at the local Kaingaroa telephone exchange, where a "Mr Currie" was the operator. Several 70-foot Oregon-pine masts (grown on the forest) supported the antennas. A second transmitter and receiver were also installed. It was a Collins transmitter and could operate on a frequency just above 5 MHz. It was used to send the daily weather and other reports to the NZ Post Office Receiving Station at Makara from where they were sent on by telephone to the Head Office of the NZ Forest Service in Wellington. I have never been able to find out just what these reports were actually used for! Back to Summary
I built my first crystal set when I was about nine or ten years old. It was made with parts from Dad's "junk boxes". He had a small tin containing galena pieces that I used for the detector. I still have that tin!
Because of the low sensitivity of my crystal set and the long distance we were from any broadcast transmitter, the only station I could hear was ZLGA!
From this crystal set, I graduated to one-valve regenerative receivers. The only valve available to me was a 1A5GT - an octal audio output pentode with a 1.4 volt filament. An audio output valve is not the best choice for an RF purpose, but when it's all you've got, it is what you use! I think this valve was a left-over from servicing one of the Forestry sets! I later obtained a 1N5GT and several other types too.
The 1.4 volt supply for the filament came from a single "Number 6 cell". These were in plentiful supply. The forestry telephone system around the Kaingaroa Forest was a single-wire earth-return system with a hand-cranked magneto and bells for ringing. Each phone had a couple of No. 6 cells inside!
The cells, when they got to me, were "flat". They could be rejuvenated by stripping the cardboard outer from them to expose the zinc containerl. Many holes were punched in this zinc using a nail and hammer. The cell was then immersed in one of my mother's preserving jars. Being war-time, my Mum grew and preserved lots of home-grown fruit and vegetables. She made lots of jam too - all on a wood-burning stove! The preserving jar was about half-filled with water and some salt added, scrounged from my mother's supply. I could greatly extend the life of these cells!
The HT supply was not so easy to obtain. Some models of transcetver used by the Forestry used "B" batteries of the 45-volt kind. I scrounged as many of these as I could. By stripping these apart, I could test each cell in turn. The cells that were "faulty" could be bridged and some further life obtained from these batteries. This was when I discovered the difference between a volt-meter and an ammeter! I also learned how to dismantle meters and to straighten pointer needles too!
The cells of various types were "installed" under my bed with the receiver supported on a wooden arm attached to the wall that I built to swing across my bed. I could listen whenever I wished! The antenna was a length of Forestry hard-drawn copper telephone line out the window and up to a tree - with some egg insulators from my father's junk box.
The "volume" of the audio output from the phones could be increased by adding more 45-volt batteries in series! My knowledge of the ratings of the valve was almost nil, being limited to what was given in the handbooks. But my valves seemed to survive! Back to Summary
This receiver provided me with lots of interesting signals. I could listen to the progress of the war from the BBC and Radio Australia, and plot the advances made by troops on my atlas. I could listen to various military networks too. My Boy Scout Morse speed was about 6 words-per-minute and increasing. This was useful for monitoring many different military circuits.
The war ended in 1945 and in early 1946 I was bundled off to boarding school for my secondary education, so my radio interests were curtailed. Back to Summary
At this time I dreamed of having a power supply and being able to build a more elaborate mains-powered receiver. The chance came during "school holidays" in 1947 when I finally obtained the components. I built a 3-valve TRF using valves of the 6K7, 6U7 and 6V6 variety with 6.3 volt heaters. It drove a speaker too - for the first time. All my previous sets used uncomfortable headphones. The speaker was an "e-m" (electromagnetic) type - with a field coil that acted as the speaker magnet and also acted as the smoothing choke for the power supply. The smoothing capacitors were wet electrolytics! The rectifier was an "80" valve.
At this time
the family were again living at Riverhead Forest. My father had been
transferred to the office of the Forest Service in Auckland. That office was in
the same building as 1ZB - a popular broadcast station of the time. I
visited during school holidays, being a boarder at Wellington College. Dad was
transferred to Wellington, to the Head Office of the NZ Forest Service.
The family now lived in a "State House" at 50 Chapman Crescent in Naenae in the Hutt Valley. The post-war housing shortage was such that we were very luck indeeed to get this house. I continued to attend Wellington College, travelling each day from Naenae to Wellington by train and then from the Railway Station to college at the Basin Reserve by tramcar. I now had the resources and the time to build a new receiver.
The receiver went through several phases ending up as a 15-tube double-change with 954 RF amp, ECC91 triode mixer and 6C5 HF oscillator. It had 1600 kHz first IF changed to 465 kHz with a 6K8. It had a 6H6 as a noise-limiter, amplified AGC with an S meter. The circuit diagram is hand-drawn, glued to the inside of the lid. An exercise book was kept with various details about the receiver. It is now brown and faded - the ink was blue, from a fountain pen! The circuit of the receiver was also recorded in this book. Receiver Circuit
The
photos were taken in January 1949 and show the stage of development at that
time. Note the use of "ZC1" IF transformers and a "ZC1" BFO
coil.
These photographs have been scanned from prints of the time, taken by me and all the processing done by me. The prints have lasted well considering they were produced by a very amateur photographer and the "fixing" of the prints used only basic chemicals.
The developing of the film and the printing was done in the "downstairs toilet" of our Chapman Crescent house. Some of Mum's blankets were used to cover up the window and the door to make a dark-room. With no ventilation and in such a small room, the air got a bit thick! But the processing of the film set the time for the task and the door or window could not be opened until the photographic developing or printing had finished!
Note the use of a separate power supply with its "80" rectifier valve - or it might have been a 5Z4 (or similar), I used both types at various times. The chassis of the power supply is an aluminium ex-army "mess tin"!
The dial of the receiver used a "planetary drive" The escutcheon was made from a piece of 3-ply wood, fretsawed to shape and painted black to look like a commercial dial! Back to Summary
The Amateur Radio Examinations were held on the first Wednesday of the months of March and September at the Radio Inspectors' premises, upstairs above the Te Aro Post Office. After sitting and passing the Morse code test (12 words-per-minute) on the September morning in 1950, and attempting the written paper in the afternoon, I had to sit through the long "wait while we mark the papers" delay. The delay gave time to construct a transmitter and a "station".
The Morse code test was not a difficulty. I had been receiving Morse signals on my receivers for many years. Dad kindly gave me some practice with an audio oscillator I had built during the weeks before the test. There were no tape-recorders or computers in those days. The only problem expected was the attitude of the Radio Inspector who examined. Some had fearsome reputations! I found no difficulties with the test.
My father did not have any operational equipment at that time. My receiver was still operational. The task was to build a transmitter.
My father was working in the Head Office of the State Forest Service in Wellington. Another radio amateur worked with him, Graham (Graeme?) Upchurch ZL2CJ. He offered to give me a lot of his surplus components because he was shifting to some other place further north. One Saturday afternoon I visited his home which was at the top of highest hill on the Whiteman's Valley Road, above Pinehaven. I arrived there on my push-bike, our family did not have any other form of transport in those days. When that's all you've got, that's what ya' use! Back to Summary
Graham provided me with lots of very useful bits and pieces, transformers, valves, and a small three-level rack and cabinet for a transmitter. This had three chassis which could be used for the antenna tuning gear (top rack), the RF circuitry (middle rack) and the audio modulator stages on the bottom rack. I planned to use my external power supply which currently supplied the receiver. The rack cabinet had a door at the back and holes for two large insulators on top! A treasured find indeed!
Graham gave me a wooden apple-box to take most of the treasures I had been given. The box was tied on to the carrier on the back of my bike. I carried the racks and cabinet balanced on the handlebars and proceded home to Naenae, loaded up with these treasures. From the hilltop down to Silverstream is a long narrow and very winding road, a steady grade which I managed to negotiate with caution, riding the brake - which was one of the "back pedal" variety! When I drive down the same hill by car today I remember the generosity of ZL2CJ in helping this young keen amateur to get on the air. I remember too riding down the same hill on my bike, loaded up with "goodies". I had not the slightest inclination that I would, much later in my life, move into a house at Silverstream near the bottom of this hill - a house that had not even been built then!
My first transmitter, built into the rack, was a 6C5 crystal oscillator with an 807 final, running about 26 watt (DC input to the final) on CW. The antenna was a half-wave doublet. The crystal used was one "borrowed" from my father's collection, 3550 kHz (or kc/s as it was in those days). Back to Summary
Our state house was double-storeyed. My bedroom, which I shared with my (younger) brother Hugh, was on the top floor. I could not figure out how to get access to such a high roof, so the only way I could erect an aerial was to attach the centre of it to the middle of one side of the house by a rope out of a window at the landing at the top of the stairs. Each end of the dipole was trapsed to the front and to the back of the property where the ends were supported on the highest poles I could find - which made it just above head-height at the ends. The legs of the antenna were kept free of the house and other obstacles by ropes. The property was too short for a straight 130-foot antenna . So the antenna had a series of several kinks - but it worked!
Unfortunately I did not have any coaxial cable, nor the funds to acquire any, so I had to use open-wire feeders. This sounds excellent, but installation was another problem. My bedroom was on the other side of the house to where I managed to attach the centre feed-point of the antenna. There was a short passage-way from the landing at the top of the stairs to my bedroom. So two wires were stretched from the window top along the hallway to above my bedroom door! There was enough clearance in the wooden window-frame and at the top of my bedroom door for these to each be opened and shut - but not hindering the feeders! My mother must have been very tolerant, I recall no objections from her, whether she was asked or not I cannot recall!
The transmitting antenna was also used as the receive antenna. The receiver was now "state-of-the-art" for the time! During December 1950 it was rebuilt to use a 100 kHz second IF which improved the selectivity. Back to Summary
Finally I received the examination result - I had passed! A trip to the same premises with 30 shillings, filling in a form, I then had to wait while the Post Office system processed my application. Finally my licence arrived in the mail. I found my callsign, ZL2AMJ. In the days before the callsign was received in the mail, I would leave the College grounds at lunch-time and use a public telephone in a phone box at the Basin Reserve to ring my Mum to ask if the mail had arrived!
My first contact was on 15 November 1950 at 7.20 pm with ZL2AHT of Wellington Street, Picton - I had crossed Cook Strait with my first QSO! This was on 80 metres, using CW. The entire station was home-constructed by me.
A modulator was constructed using a ZC1 carbon microphone (because it was available!) a 6J7 speech amplifier, 6C5 phase-inverter, to a 6N7 wired as a push-pull modulator with a power transformer as the modulating transformer, anode modulating the 807. DC power input was about 20 watt.
The next project was to add a VFO. This was made using a 6C5 Clapp oscillator with a 6F6 buffer-doubler. The whole 80-metre band could now be covered!
During December 1950 I shifted my station from the first-floor bedroom to the garden shed at the extreme back of the property. The mains supply came to the shed by a long cable which I laid over the ground from the house! I rolled the cable up when not in use! Being now near to the end of the antenna, I experimented with end-feeding it, changing it to a "zepp". During March 1951 I experimented with controlling the transmitter remotely from my bedroom. Back to Summary
A portable transmitter was constructed using a 6C4 Pearce oscillator with a 6V6 final, 6C4 speech amplifier and 6V6 Heising modulator. The DC input was some 8 to 10 watt. This rig was carried in my luggage to a farm near Ohingaiti where I stayed with a college friend. The friend, John Ramsay, later became ZL1KG at Whangarei. The receiver used was an all-wave Atwater-Kent, the family's house receiver. It was unusual for a house to have more than one domestic receiver in those days!
Using this temporary station enabled me to work to my own home station, Dad operating it at Naenae with his callsign ZL2GA. This avoided the cost of phoning home and having to pay toll bills which were expensive at that time.
John had an ex-services war-surplus "21 Set" and we tried to get that going at various times too, sometimes successfully, with several contacts. Back to Summary
I remember, some time around 1946 or 1947, while still at boarding school, seeing a taxi parked in Lambton Quay, Wellington. It had two-way radio on board! Gee! What next! It seemed to be unbelievable! The boot space was about half-full with the radio gear!
After we moved to Naenae, I made several super-regenerative receivers to listen to the taxis. In the Hutt Valley at that time they were operating just above 100 MHz using amplitude modulation. I also made some "parallel-line" oscillators of various kinds. These were to operate on the "2-metre band" 144 to 148 MHz. The frequency was "found" by using lecher-lines to measure the wave-length of the radiated signal. On a super-regen receiver I could sometimes hear some distant 2m amateur signals too.
The valves used were acorns, 955 triodes and 954 pentodes in the super-regen receivers, and an E1148 or HY615 in the parallel-line oscillators. My father had acquired some of these valves from somewhere.
The audio circuitry from my "portable" transmitter was used to amplitude-modulate this line-oscillator, a "modulated oscillator!
Then I had a stroke of good fortune. A pair of 958A acorns were obtained. These have a 1.4 volt filament. This enabled a pair of 144 MHz "Handie-talkies" to be built. This rig is described in the 1946 ARRL Handbook on page 362. Two valves were used to serve on both send and receive - on receive a super-regenerative receiver with one stage of audio driving a single earpiece, and a modulated oscillator when on transmit. A type DL92 (1S4) miniature 7-pin was used in my version for the audio stage.
My father and I used these two "hand-helds" to communicate around Naenae. They were great fun. Each had a 67v "B" battery and a 1.5v "A" battery. These batteries were quite expensive and the experiments stopped when the batteries died! I would set out on my bike and would report back from various points to check the coverage!
In January 1951 I started work at Shelly Bay with the Civil Aviation Administration, travelling to Wellington daily from Naenae with Doug Berry ZL2AJT who worked in the Stout Street Government Building for a government department. One lunch hour, on 7 August 1951 at 12.15 pm, we worked each other. He was on the roof of the Stout Street Building, I was at the Massey Memorial. Our cross-water, across Wellington Harbour, two-way contact on 144 MHz was determined from a map to be 2 miles and 50 chains! The antennas were rods attached to the small transceivers! Again, entirely home-made gear was used! We repeated the contact on the next day at the same time.
The greatest "DX" with one of these transceivers was with ZL2CX, on 29 September 1951 at 7.35 pm. He was located in Wadestown! I had a 2m yagi at Naenae. We estimated the distance to be 12 miles. I had previously worked ZL2CX on the mains-powered lecher-line modulated oscillator and super-regenerative receiver.
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