Plessey SL600 Transceiver

Image of my transceiver along with my 144Mhz transmitter and Hallicrafters SX24 receiver.

Last week I read an interesting article in RADCOM about the SL600 series of chips back in the 1970's and 80's. The article concerned the SL641 or SL1641 VOGAD chip.
Back in the late 70's I built a complete SSB hybrid transceiver for 160m and 80m. It was based on the SL600 transceiver by G3ZVC. The SL600 chips were abundant at the time and I purchased mine from Birkett's. Most were 'untested', but all of them worked a treat and were very cheap! The SL600's came in metal TO5 cans and were supplied by Birkitts with data sheets. (Which I still have)

When I built my transceiver I remember making a PC board for the G3ZVC circuit, but I can't remember if I used it or made descrete boards??  I know that building this transceiver was the biggest construction project that I have ever made. I bought an XF-9B SSB filter and crystals which was the most expensive component and also a new Eddystone 898 dial for the front. (I just love the Eddystone 898 dial!) The transmitter used an EL84 valve in the PA giving about 20 watts PEP output on 160m and 80m. The MD108 diode mixer was a brilliant piece of kit, so easy to use and no tuning.

On reflection, this transceiver was pretty amazing, parts of it were my own designs or adapted from circuits in RADCOM or handbooks. Getting it working was frustrating and I had to re-build parts of it. The VFO caused some problems, as did the power supply which was built on-board the chassis. A lot of metalwork and construction, but the SL600's were great! If I remember right I used a couple of SL610's in the RF stage, but the front end was a bit 'deaf' with the SL610 and I ended up building a pre-selector to improve the reception.

My transceiver (left) with 144Mhz transmitter, SX24 receiver and (above) 432 Mhz tripler and transmitter.

What I don't understand is why I decided to take it all apart, I know I had lots of niggling problems, but the project was worthwhile. I think it was in 1980 when for the very first time I bought an HF transceiver - the Yaesu FT101E (which I still have) I took it apart to concentrate and make more room for my FT101E. What a silly thing to do...I would love to still have that transceiver now just to admire the work I put into it!  Also, why did I not take photos of it!

Yaesu FT817 stand

Now here is nifty little trick for anyone who has a Yaesu FT817 or other portable transciever. Last week I went into 'Poundworld' and spotted a fully adjustable folding stand for an iPad or tablet, so I bought one to support my Tab 2 tablet. Then I realised that this little stand fold up in different ways and is ideal for my Yeasu FT817. Great for a quid! 

Now I need another one for my Tab 2...

Carry on blogging!

Last week I spent an afternoon at Heathfield Primary School where the children could showcase their blogs. At my school I introduced blogs about six years ago and we were a kind pioneer in using blogs in the classroom. At the time we used Blogger to set up some class blogs. The children loved it, but often didn't get the opportunity to blog independently. Later, the school's firewalls wouldn't let blogger through and things came to an abrupt end. Meanwhile, at Heathfield Primary School, David Mitchell who was Deputy Head at the time realised the impact of children blogging and the positive effect it has on their writing ability.

My school have also been blogging, this time using Wordpress, which, I must admit, is harder and not as user friendly as Blogger. Now all our classes have blogs and are using them.

Tonight I downloaded an app called Classdroid on my new Samsung Galaxy Tab 2, this allows you to take a photo of a piece of work, grade it and upload it onto the class blog - amazing!

I also learned more about QR Codes and Tabs when using blogs.

Digital Pope

A bolt of lightning - surely not a message from above - was photographed striking the lightning rod on the top St Peter's Basilica,

OMG! The Pope has resigned...how can that be? Popes don't just 'resign', its a bit like golfers who just grow old and loose their balls! 

Well, now it has happened what will the new Pope be like analogue or digital? 

Maybe we need a 'Digital Pope' who can bring the Catholic Church into the 21st Century... a scientist maybe?

This was interesting and fun to read today...take note Brian Cox!

To: The Vatican (HR Department)
Name: Dean Burnett
Date: 11-02-2013
Reference: Vacancy CCLXVI ('Pope')
CV: [Attached]

PERSONAL STATEMENT IN SUPPORT OF APPLICATION: See below
Dear Sir/Madam/Holy Ghost
I am very interested in applying for the recently announced vacancy for the position of pope. I am sure you've received many applications already, but I believe I would make an excellent candidate for the role as I could bring innovative new approaches and help increase diversity, which would have the effect of both motivating those involved in and enhancing the reputation of the organisation (i.e. The Catholic Church).

I have read the job description and although I admittedly do not meet all the specified essential criteria for the role (e.g. I do not regularly commune with God or any other unspecified deity) I feel that my strengths in other areas more than make up for my lack of direct experience.
Although I am not a practising member of the Catholic (or any other) Church, I am a qualified and enthusiastic scientist. I believe this makes me an ideal choice for the next pope, for a number of reasons. For example, I have had many jobs where it is compulsory to wear a white coat, and the wearing of long white garments appears to be the main duty of the pope. I also regularly lecture on the subject of neuroscience, so am extensively experienced at speaking in an unfamiliar language to rooms full of people who are struggling to stay awake, so it would be no trouble for me to offer Mass whenever required.

I am not a cardinal, but a recent check of my wallet reveals that I still have a membership cards for both GAME, Blockbuster Video and MVC, showing that I am clearly dedicated to declining institutions and have a robust if unrealistic belief in resurrection.
As an atheist scientist I cannot claim to be in regular contact with God per se, but I have regularly encountered professors with equivalent levels of power and influence who demand unquestioning obedience from those who serve them, so feel this has provided me with equivalent professional experience required for the position.
As a scientist pope, I could bring an element of rationalism and logic to the Catholic Church, which would better equip it to survive in more modern, enlightened times. I could provide numerous plausible-sounding theories as to the origins of the universe, life, evolution, human consciousness and any other area that the Church feels it should have influence over. Whereas most scientists require evidence and peer review before their theories can be accepted, my being the pope would mean I was infallible so I wouldn't have to go through this process; the simple act of me saying it would mean it is accepted by many as fact. This is a privilege enjoyed by only a few scientists, and one I definitely wouldn't abuse, scouts honour!

I have performed a number of miracles in recent years. For example, I have managed to sustain a career in science in present circumstances, despite having very few notable publications to my name and a disastrous history of high-profile embarrassments.
I have managed to remain in my post despite these numerous blunders, so I would be able to bring this experience to my duties as pope. I can also turn water into wine, which is viewed as more of a "classic" miracle. It takes some time as it involves me pouring the water onto grapevines before growing, picking, sorting, crushing, fermenting, maturing, bottling and selling. But overall, it's definitely water being turned into wine. With Science! (Unless that doesn't count as a miracle, in which case it's clearly magic).

I am not presently celibate, but as a teenager who was a big science fan with terrible acne, I am very familiar with the concept. I am also not a homosexual, as that would obviously exclude me from the role (NB. In the interests of transparency, I did once suck a penis, but I didn't inhale so it doesn't count). At the last count, I also have the required number of testicles to be pope (at least two). I also have experience with covering up crimes.

I believe these qualities and more make me an ideal candidate for the position, so I hope you will consider my application seriously. I realise the vacancy is somewhat above my pay grade, but I am looking for a higher paying position as I need money to provide for my family … I mean buy condoms … I mean jewels.
I look forward to hearing from you.
Vestrum fideliter

Dean Burnett

BETT 2013

BETT 2013 has just finished. Each year in London there is a huge exhibition of Educational Technology...ICT for Schools. I have always avoided going to this monster 'sell, sell, sell' event and every year it gets bigger. OK...last year I got a free mug from 'Education City' from a friend who went. It was fun when I read this, comparing BETT with IKEA. I'm sure that if I went I would react in the same way!

"I don’t like IKEA. I’ll tell you why. It is because of what I call ‘IKEA Fear’. The symptoms of IKEA Fear are a mounting sense of disquiet that commences the minute I pass through the large revolving doors. This disquiet worsens progressively as I meander first through immaculate living rooms, on through offices, bedrooms and kitchens until it becomes something visceral within my chest and stomach, usually around the time I reach the carpet, curtains and cushions – urging me to run screaming from the building clutching at my hair.
I have contemplated this feeling and the possible reasons for it. I have a theory based upon nothing other than my own tenuous guesses. I think my problem may possibly be similar to conditions such as agoraphobia or claustrophobia, and here are a couple of exacerbating factors:
• There is a disorientating absence of any reference to the outside world. If you are lucky, you might glimpse a rectangle of far-off, semi-industrial car-park through a distant fire door (the location of which is noted in the event of a panic-induced exit in due course).
• There is a disturbing juxtaposing of comfy, soft, homely environments in which you can sit and imagine oneself in the bosom of family relaxing after or during a meal… until you look up and witness the horrific, industrial tangle of ducting and steel. I don’t mind telling you that this contrast messes with my head.

Now, on to the BETT Show 2013. This year, it relocated from Olympia to Excel- a move I welcomed initially as it certainly improved accessibility for me. This welcome feeling was short-lived. On arrival at Excel, I attempted to feel upbeat and optimistic but that familiar disquiet, the IKEA Fear, started to creep up on me. I apologise to those friends of mine whom I encountered on that first morning, my brow knitted and jaw slightly tensed. I put on a brave face and greeted you enthusiastically but I wasn’t quite myself. Walking the (seemingly) mile-long boulevards, snickets and ginnels of the exhibition space, my anxiety mounted until I had to make a swift exit. David Mitchell and Julia Skinner were fortunately on hand to scoop me up as I composed myself over some lunch with them.
I struggled throughout the two and a bit days at the show. My misery was mitigated only by the wonderful encounters I had with lovely people. The social, the teachmeet, the laughs and the learning mean that I won’t be boycotting in future. I will take the rough with the smooth.
I miss Olympia. I miss the quirkiness, the characterful architecture, the nooks and crannies, the expanse of sky spread out above. I also miss the opportunities for out-of-body elevations to the balcony for welcome, reorienting breathers during which one could see the layout, establish the landmarks or spot a friend to pursue.
Oh, and I didn’t even see anything especially exciting or innovative in those long corridors of anxiety. Next year, I will dedicate myself to establishing quick exit routes whilst also seeking out people – after all, it is them that make a visit to BETT worthwhile."

FDK Multi Palm IV

Today I was playing about with a Multi Palm IV 70cm FM handheld. I have had this little rig in my possession for years now hidden in the attic along with lots of other 'junk' from the olden days.
This little handheld came out around 1979 and was ahead of it's time. I remember trying to build a transverter for 70cms then and it was difficult to build and tune up. The Multi Palm was small, very compact and stable. It was crystal controlled with a built in shift and tone burst for repeaters. Today I connected a 12v PSU and it worked fine. I could hear GB3CR repeater as good as my new Baofeng handheld.
Inside are a bank of small nicads, which don't seem to work any more. The rig gives an output power of 1 watt on 70cms.

I took the back off to remind myself of the analogue electronics inside, remember, there was nothing digital then. A lot of stuff packed into a small space! I wonder if you can still buy the packs of nicad batteries? Back in 1979 Birkett's would sell packs like this at some of the radio rallies dead cheap.

If you lift up the main board you will find the bank of six crystals which can be changed for the particular channels that you want. The ones fitted at the moment are: RB2, RB4, RB6, SU8, RB10, SU20.

Block Diagram of the FDK Multi Palm IV (Click to enlarge)

Circuit Diagram of the FDK Multi Palm IV (Click to enlarge)

HMV

What is happening to the world of retail?

Soon there will be no stores at all left in our town centre, just pound shops, mobile phone shops, pawn shops and banks!

I remember the days of shopping in Bolton where you could spend all day there browsing round the shops. I loved the record shops! Bulloughs on Knowsley Street, the Co-op on Bridge Street and later Russells, Our Price, WH Smith and Andy's Records.
I find it hard to pay money for something that I cannot hold in my hand and 'keep'. Vinyl LPs with their covers are something that you saved up for and treasured, often reading the sleeves and looking at the pictures while you listened to them. CD's gave us quality without the crackles and scratches, but they sort of took away the feel of a Vinyl album.

Now it is digital, but lets stop here....MP3???  Where is the audio quality in that?
You pay for a digital download to listen on your computer or phone in audio quality on parr with Medium Wave Radio!  What has happened to the high quality Stereo Amps and Speakers?  How many people are listening to their digital downloads on Rotel Amps and Wharfdale Speakers?
People don't seem to have the time anymore for 'quality' listening, life is too fast, music on the go. We seem to be going back in time in the analogue world to the time when we listened to music on a 'record player' with a tinny speaker. In those days we strived for better 'quality' audio production. Now we have it we are going in reverse!

Technology has shot itself in the foot!

Now HMV the last remaining music store is poised to shut, soon CD's will be a thing of the past and we will be doomed to the digital downloads stored in the 'clouds' of digital technology.

Latest news...now Blockbuster have joined the insolvency club!
Members now include: Woolworths, Game, Comet, Jessops, HMV, Blockbuster...I wonder who is next to join?