Comment – Woody's Workshop

June 22, 2024June 24, 2024

TA12 USAF WW2 transmitter and 1938 Truphonic MA5T receiver

Time to say goodbye ?

Like all engineers and particularly radio engineers I have a squirrel mentality heavily influenced by emotional attachment. I tend to keep stuff. This is part ‘might be useful one day’, a symptom of my ‘make do and mend’ upbringing and part not being able to bear parting with things.

This weekend is the Newbury Amateur Radio Club annual meet and sale. Together with two likeminded techies we have booked a couple of tables to offload some of our accumulated junk.

I have decided to take two items that meet the emotional attachment category. They both have a story attached that relate to how my interest in radio evolved.

The first is my maternal grandparents Truphonic MA5T domestic radio. As a family we regularly visited them at their ‘2 up – 2 down’ terraced house in York. The radio sat on their sideboard in the kitchen and it totally absorbed me as I would tune up and down the bands and fiddle with the preset station levers. Truphonic were a London based manufacturer and the MA5T was an upright version of the MA5, both of which dated around 1938. The valve line up was TH4B\TDD4\VP43\PENA4\1W3. When I wasn’t playing with their radio I was taking their torches to pieces and making circuits with light bulbs. The technical seed was sown.

The second piece for disposal is a TA12 USAF airborne transmitter as used in WW2 on board B17s etc. It runs a pair of 807s. The story around this is similar.

My radio interest had blossomed and through a contact of my father I had acquired a WW2 R1155A receiver from a radio amateur in York. I became an avid shortwave listener. Wire antennas festooned the back garden and I spent hours with headphones clamped to my head searching for signals from round the globe.

Those familiar with the R1155A will know that its short wave coverage begins at around 3MHz and completely misses the 1.8MHz to 2MHz amateur band known as Top Band. If you were lucky enough to own a R1155N this band was covered but the N model was much less common being used mainly for marine comms rather than bomber command.

However as a family we had a Pilot Blue Peter domestic radio which covered LW/MW and SW frequencies. Unusually it had continuous coverage across these bands. This meant it covered Top Band. This was somewhat unusual for a domestic radio. Occasionally I would switch it on and tune around and one night happened upon a very strong amateur signal on Top Band. Given that the Pilot had little or no antenna connected the transmission had to be local. This was my first contact with Alf Whitelock whose callsign was G3BNM. He was indeed local and lived in Alne which was around 9 miles away.

This was the start of a long and close relationship with Alf. He took me under his wing and taught me so much about radio both operating and building. He was regularly on Top Band with his nephew John G3WQM and Ted G3TNM. Alf ran a pseudo crossband duplex transmission retransmitting the incoming audio from John (4m) and Ted (2m) and so all three of them and anyone listening to Alf could hear everyone talking.

Alf helped me improve my R1155 with external pre-amps and converters so I had full coverage of all the amateur short wave bands. I would regularly bike to and from Alne and would always struggle on the return journey with so many donated radio parts strapped to my bike.

Alf was not young and inevitably he died when I was in my late teens. I was devastated. I felt like I had lost a very special adopted grandfather. He left me his HF station. It was a 6 foot high rack with huge power supplies, modulators and antenna tuner. The heart of the station was the TA12 airborne transmitter. While all the other components have long since gone, I could not bear to part with the TA12 and it has remained with me now for over 50 years. He voice came to me via this radio and it has a very emotional connection.

So what to do ? Two items of huge sentimental value that is personal only to me. My kids don’t care for granddad’s weird hobbies and my accumulated ‘junk’. On my passing both these radios will go to landfill or similar. Taking them to the Newbury event might stir some interest with a historic preservation body. I can then rest knowing that these two radios have moved on and will have an extended life.

But maybe I’m just hoping that nobody shows any interest and I can bring them back home and put them back in the attic for a few more years …..

UPDATE : Both the TA12 and the MA5T sold. Both went to heritage radio collectors. The buyer of the MA5T said he had never seen this particular model and thought it very rare. He was looking forward to restoring it. Result.

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October 14, 2023October 14, 2023

Sending a SMS text message to the EU from UK

Success depends on your network provider

Since the UK left the EU we found that we could not send SMS messages via Vodafone to our neighbours in France. Despite asking we never did get an answer why this was a problem. Vodafone also removed free roaming when in the EU and added a daily charge even if you only sent a single SMS or made one call.

Our contract with Vodafone was due to expire this month so we shopped around with a number of alternate providers and in the end decided to switch to giffgaff. This is a UK service provider that uses the O2 infrastructure in the UK. Big plus – they offer free roaming in the EU. The change over process was very simple to do and we ported our old Vodafone numbers using a PAC code. We were probably ‘off air’ with our numbers for less than 24 hours. It was a totally web based transfer with clear instructions and regular text and email updates from giffgiff on the transfer progress.

Once up and running on giffgaff I tried sending a SMS to France. I got an error message from giffgaff. While we will be paying a monthly service charge this does not include International Calls which is how my SMS was regarded. The solution is to put a small amount of money on an ‘extras’ account that sits outside the normally monthly billing. My SMS was then delivered to France and cost me 24p. We can live with that for the number of times we need to send a ‘we will be arriving’ message to our neighbours.

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July 20, 2023July 20, 2023

Exactly by Simon Winchester

Some engineering bedtime reading

For a recent birthday my wife bought me the above book. She had no idea if it was something that would appeal to me but figured that my engineering brain might enjoy it.

It is subtitled ‘How precision engineers created the modern world’ and I have to admit that I have been unable to put it down. It is an easy read but a thoroughly absorbing read that begins with navy cannons and ends with modern day chip processes having visited people like Rolls-Royce, Frank Whittle, Henry Ford etc.

If you love engineering I would recommend it as a read and should emphasise that I have no affiliation with Simon Winchester.

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November 11, 2022November 15, 2022

Addis Thermopot and Derek Palmer

A convenient way to make a cuppa

This one is a bit of a curved ball story and won’t appeal to all readers …. but is worth recording.

In the 1970s my business was in its infancy. I was working from home trying to get things moving. One lunchtime we had a knock on the door and on answering it I was met with an individual saying “Hi I’m Derek and I am your Farnell Electronic Components rep and I’m taking you out to lunch”. So began a working and personal relationship with Derek Palmer and FEC that lasted many years.

Derek eventually resigned from FEC and began trading as Turnkey Manufacturing Ltd, a one man company specialising in sourcing electronic components, assemblies and services from the Far East. As a Company we continued to use Derek to source items for us.

In the course of his travels in the Far East Derek came across the Thermopot concept. This was a stored hot water boiler that gave ‘close to boiling water’ on tap for making hot drinks. Derek grasped the potential for such an item in the UK market. He began working with the overseas manufacturer to adopt the idea to meet the EU market standards. Very soon he and his wife Jan had a growing business selling the Turnkey version of the Thermopot.

The Thermopot was not perfect. It came in two versions, either a 3.5L or a 5L capacity. In theory it kept the water at a constant temperature of 98C but this was not always stable. The water tank had a sealed lid which stopped the water from de-oxygenating. It had dual heating elements, one for initial boiling and one for maintaining the temperature. An electronic controller managed all the functions.

Needless to say Derek persuaded us to buy one. Our initial cynicism abated and our kettle was soon relegated to the back of a cupboard.

The story now takes a sad turn. One morning in 2014 Derek woke up and went downstairs to make a drink where he collapsed and died. We regarded Derek as an honorary member of our Company such was the relationship he had with us. Everyone was shocked by the loss. I am sure the same feelings were expressed up and down the country in many other small companies that had come to know him.

Jan, Derek’s wife, sold the rights to the Thermopot to Addis who market a wide range of household wares. Over the course of time we have had one or two replacement Thermopots from Addis. It would be inappropriate to comment on their level of customer support other than to say that it is not on a par with how Derek believed customers should be looked after.

Last week our current Thermopot went AWOL. Out came the kettle to keep the cups of tea flowing. Rather than waiting for Addis to respond we decided to just buy a new one. We discovered two things. First of all it is cheaper to buy one on EBay direct from Addis rather than Amazon. Secondly the pictures on EBay of the front panel suggested that there was an updated version now being offered. This was confirmed when the delivery arrived. I have to report that so far the new version keeps the water temperature at a very stable 98C and our cups of tea are much the better for this. The pump that streams the water also has a higher water flow rate.

Being of an engineering mind I stripped down the broken one. It was quite basic on the electrical side. What surprised me was that there was no insulation material around the hot water vessel. This would have greatly improved its energy efficiency. Judging by the temperature of the case on the new delivery, there is unlikely to be insulation in the new model either. Perhaps something for Addis to consider in the next iteration ?

Sorry that wasn’t of much interest but at least Derek Palmer is now enshrined in internet lore. He was a lovely guy, keen sportsman and full of fun. He is very sadly missed by all who encountered him. Whenever we make a cup of tea we think of him.

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June 30, 2022July 2, 2022

Solar Energy servicing issues

We have a ‘wet’ solar panel for our domestic hot water (DHW) and a 3kW PV array to supplement our electricity consumption. We benefit from a feed in tariff for the excess power fed to the electric supply grid.

The DHW system is a 1 metre square grid of evacuated tubes feeding conducted heat through a closed loop pipework to a secondary heating coil in the hot storage water tank. The system was installed in 2008 and has given good service and lots of hot water. Recently the temperatures at the panel on the roof were showing very very high (>100C) and a closer investigation suggested that there was no circulation of the heat transfer fluid.

I registered a service call and the technician duly arrived. The conclusion was that the transfer fluid had degraded, leaving mainly gas and debris in the system pipework.

The technician pressure washed the pipework loop and refilled it with new transfer fluid. The system is now back up and running. He made a not so subtle suggestion that maybe leaving it for 14 years between service intervals might not be a good idea …. hint taken.

The other topic of conversation revolved around holiday absences and hot sunny periods. When we go away on holiday we ask the kids to regularly run off hot water otherwise the hot water storage tank just gets hotter and hotter. This results in the roof panel venting under the pressure.

The technician commented that the latest controllers have a reverse action facility which you can enable during holiday absences. This reverses the transfer fluid flow so the heat in the storage tank water is conducted out to the roof panel at night where it is radiated off. Unfortunately our controller does not have this facility. Maybe in four years time when we have a maintenance service call we can arrange an upgrade ….

While investigating the problem prior to service visit I went up on the roof to check the DHW panel. (We live in a single storey house so reduced Health and Safety risk …). While all seemed OK, it was noticeable that both the DHW panel and the PV panels were dirty. I always clean them early in the year but we have recently had rainy periods where Saharan sand gets deposited via the rain. This was clearly visible on the PV panels and less so on the water panel.

As a result of this, this morning has been a panel cleaning session. Every kW counts. Keep your panels clean.

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