UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Radio (domestic)

Notices

Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only.

Closed Thread
 
Thread Tools
Old 12th Dec 2019, 2:00 pm   #81
Oldmadham
Pentode
 
Join Date: Sep 2019
Location: Perth, Western Australia, Australia.
Posts: 199
Default Re: Nostalgia? Probably.

Quote:
Originally Posted by rambo1152 View Post
Quote:
Originally Posted by Skywave View Post
And since 'electronics' is such a vast subject, there is always something new to learn. I think we've all met a chunk of circuitry (or even a complete item) which upon first inspection invokes the response "Huh? What that's for? How does that bit work?"
So true. Case in point, after watching the latest Big Clive video it occurred to me that I had never built anything containing those now ubiquitous power MOSFETS. I must have blinked and missed how they'd made the quantum leap from small signal RF, to power switching. I've ordered 50 of the ones he was using for about a quid. No idea what I'll do with them.
Most of today's generation have no idea that MOSFETs were used in RF stages.
The only ones they know are used in power applications.

Commonly, they either regard RF as "black magic", or at the other extreme, try to apply low frequency techniques to RF designs.

I have lost count of the number of "radio receivers" that appear in the "beginners' section of electronics forums, with plaintive cries of "I built this, & it just oscillates."

Checking, you find a bog standard Op Amp with an LC network tacked on, inadvertently changing the negative feedback into positive feedback.
Tell them, & they don't believe you!
Oldmadham is offline  
Old 12th Dec 2019, 2:30 pm   #82
Skywave
Rest in Peace
 
Join Date: Jun 2006
Location: Chard, South Somerset, UK.
Posts: 7,457
Arrow Re: Nostalgia? Probably.

Quote:
Originally Posted by Oldmadham View Post
I have lost count of the number of "radio receivers" that appear in the "beginners' section of electronics forums, with plaintive cries of "I built this, & it just oscillates."
Many of these designs for beginners fail to explain the importance of appropriate layout and the need for screening. 'Beginners' need to learn that with R.F. circuitry, there are components - usually of the reactive type - that are invisible. That necessary learning comes with experience and an increasing ability to analyze and understand how the circuit works.

Al.
Skywave is offline  
Old 12th Dec 2019, 3:35 pm   #83
stevehertz
Dekatron
 
stevehertz's Avatar
 
Join Date: Sep 2011
Location: Rugeley, Staffordshire, UK.
Posts: 8,809
Default Re: Nostalgia? Probably.

Quote:
Originally Posted by Skywave View Post
Quote:
Originally Posted by Oldmadham View Post
I have lost count of the number of "radio receivers" that appear in the "beginners' section of electronics forums, with plaintive cries of "I built this, & it just oscillates."
Many of these designs for beginners fail to explain the importance of appropriate layout and the need for screening. 'Beginners' need to learn that with R.F. circuitry, there are components - usually of the reactive type - that are invisible. That necessary learning comes with experience and an increasing ability to analyze and understand how the circuit works.

Al.
Indeed. I remember reading - it may have been on here - a guy was saying how back in the early days of wireless, as a boy he constructed a basic battery set using a plank of wood as the 'chassis' for the project. He carefully wrapped the wiring connecting each component around a pencil to form neat coils rather than what could have been a 'rat's nest', point-to-point approach. Of course, it didn't work. It took him some time to work out that his pretty interconnecting wires were now in fact inductors and were having a rather large effect on the ability of the set to perform!
__________________
A digital radio is the latest thing, but a vintage wireless is forever..
stevehertz is offline  
Old 14th Dec 2019, 2:31 am   #84
Skywave
Rest in Peace
 
Join Date: Jun 2006
Location: Chard, South Somerset, UK.
Posts: 7,457
Default Re: Nostalgia? Probably.

We learn from experience. But 'experience' is a bad teacher. It gives you the exam first; the lesson then comes afterwards. The defence against that as a newcomer to any technology is to read and to study as many technical reference books by well-known accredited authors as you can. Then attempt something simple - and experiment with it!

As a beginner to radio, Practical Wireless magazine, the Practical Wireless Encyclopaedia (F.J. Camm) and then the Radio Laboratory Handbook (M.G. Scroggie) taught me a lot. As time progressed, silly errors were reduced, but not entirely - even to this day, now that I'm 70 years of age, I occasionally find myself thinking "Why, oh why did I do that! That's never going to work properly!" Of course, technology in most subjects that interest me tends to advance faster than I can keep up with it - but that does keep the brain exercised and also prevents boredom! Meanwhile, the 'round-to-it' pile just keeps on growing!

Al.
Skywave is offline  
Old 14th Dec 2019, 7:57 am   #85
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,801
Default Re: Nostalgia? Probably.

Quote:
Originally Posted by Skywave View Post
Then attempt something simple - and experiment with it!
Al.
Another problem rears its head here. Most beginners assume simplicity is the reciprocal of component count. This attracts them towards stripped-out circuits where components do multiple duties, rife with interactions and often requiring parts to be selected.

To spot a good circuit, which has been designed to tolerate component tolerances takes almost as much knowledge as it takes to design it. This is very unfortunate because beginners can easily be discouraged by their experience in trying to build a poor design.

As a kid, I saved up and bought a transistor radio kit. I didn't know it, but it was junk. I also didn't know anyone to ask for help. I got angry with myself and set out to learn how to do it properly. As I learned more, I came to realise that kit could never have done what the adverts said. It would have been so easy to have given up and switched to stamp collecting, model trains or choral singing.

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is offline  
Old 14th Dec 2019, 1:38 pm   #86
Skywave
Rest in Peace
 
Join Date: Jun 2006
Location: Chard, South Somerset, UK.
Posts: 7,457
Arrow Re: Nostalgia? Probably.

Quote:
Originally Posted by Radio Wrangler View Post
. . . and set out to learn how to do it properly. As I learned more . . .
Perhaps you'd like to tell us about the path you took "to learn how to do it properly".
Thanks.

Al.
Skywave is offline  
Old 14th Dec 2019, 1:44 pm   #87
Station X
Moderator
 
Station X's Avatar
 
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,192
Default Re: Nostalgia? Probably.

When I was much younger I built things, not just radios, to published designs and I accepted the fact that they wouldn't work first time. I then turned to the theory and generally managed to fix them. Just reading the theory wasn't enough, I had to have the hardware in front of me.
__________________
Graham. Forum Moderator

Reach for your meter before you reach for your soldering iron.
Station X is offline  
Old 14th Dec 2019, 2:44 pm   #88
'LIVEWIRE?'
Rest in Peace
 
'LIVEWIRE?''s Avatar
 
Join Date: Mar 2006
Location: N.W. Oxfordshire(Chipping Norton)
Posts: 7,306
Default Re: Nostalgia? Probably.

Many years ago now, an instructor used a saying 'Theory without Practice is lame, and Practice without Theory is blind' (Hope I have that the right way round!), which I guess sums things up very well.
'LIVEWIRE?' is offline  
Old 14th Dec 2019, 3:58 pm   #89
AC/HL
Dekatron
 
AC/HL's Avatar
 
Join Date: Nov 2003
Location: Heckmondwike, West Yorkshire, UK.
Posts: 9,637
Default Re: Nostalgia? Probably.

Quote:
Originally Posted by Skywave View Post
Perhaps you'd like to tell us about the path you took "to learn how to do it properly".
It's different for everyone. I'd think that the only common points are slow and methodical, whichever route your personal strengths take you down.
AC/HL is offline  
Old 14th Dec 2019, 6:23 pm   #90
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,801
Default Re: Nostalgia? Probably.

Quote:
Originally Posted by Skywave View Post
Perhaps you'd like to tell us about the path you took "to learn how to do it properly".
Thanks. Al.
I dumped my standing order for practical electronics at the newsagent and moved over to Shortwave Magazine where things seemed a lot more serious. I'd have loved to join the RSGB and get the Bulletin, but you needed to know someone already a member. There was one obvious radio amateur in the village, but with a reputation that made him someone you wouldn't choose to approach. So the RSGB was out. Austin Forsyth it was.

I read avidly, I bought books at Miss Taylor's in Macaulay street then King street. I was one of Jim Fish's first customers when he opened up on Milford street.

A schoolfriend's father turned out to be an inactive amateur, (and not in the RSGB) He loaned me loads of SWM from the fifties, and a 1956 edition of the ARRL handbook WOW! was that something.

Apart from reading (all the above and anything I could find in Huddersfield's rather grand library) I started building progressively better oscilloscopes and my savings had recovered enough to buy an AR88.

I wasn't sure what sort of job I'd wind up with. TV servicing seemed obvious to my parents, but I'd heard the course took six years. How true this was I didn't know. But degrees came in 3 year and 4 year varieties. I wanted to get some industrial experience so I took the four year sort... hey, I was still winning two years on the colour TV course!

The main industrial experience turned out to be a year in R&D at HP doing test and measurement equipment. This was amazing. I was in a lab of about 100 engineers all of whom had the time and inclination to explain things.

I wnnt back to finish my degree with a solid offer of a job in my pocket. There were other offers, but I went back. It was an amazing experience. There were a few bad managers and towards the end some bouts of corporate silliness, but overall I may be one of the luckiest people alive. Other experience was at Rolls-Royce (aero engines). When HP then Agilent pulled out of hardware development and shut down the plant, I was looking for a job. Rolls Royce and Hewlett Packard as previous employers seemed to make my CV a bit scary.

at HP, i hadn't been interested in management jobs, yes the pay was better, but I was interested in going wider and deeper in electronics. I would up having to be a project manager for a time, but I didn't enjoy it and I was filling in for someone decent who had been shafted by one of those bad managers. Not at all nice. I originated and did the main design for what became the Agilent noise figure analyser, the replacement for the HP 8970 family. I know what the sales were, so overall, they must have shipped between a quarter and a third of a billion dollars of them. Big numbers, but I just got the routine salary. My noise sources are still in production.

Somewhere along the way I wrote the oscillators and synthesisers chapter for the ARRL handbook. I felt I was repaying a debt. One letter from Dave Newkirk at the ARRL who was editor at that time said they'd not received material of this quality before. But that's ambiguous. It could have been rather bad Thinking back to reading that 1956 edition by torchlight under my bedsheets, I wrote what I thought would have helped me If it could have got back via a timewarp or something.

So, read lots. Think about what you read. Build things. Don't assume published articles are any good. Learn to be selective.

With the internet, there is far better access to information, but so much of it is crap. Complete twaddle gets repeated so often it begins to be taken as truth. Selectivity is crucial.

DO NOT shy away from difficult subjects... Control Theory, Filter design. They are crucial elements. the people who can wrangle them are rare and valuable. They aren't even difficult, they just involve some alien concepts. Lecturers in these areas write nice easy exam questions... they are so so grateful for anyone picking them in papers with options. Afterwards you find that their maths has given you the keys to the universe.

I was just lucky, there were opportunities taken, but it wasn't planned. Just insatiable curiosity. Someone wrote that I had enough curiosity to kill a cattery. I still do.

Maybe I ought to thank Lasky's for that lousy kit. At the time, though, they would have got their lights punched out.

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is offline  
Old 14th Dec 2019, 6:49 pm   #91
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
Default Re: Nostalgia? Probably.

My path to "learning how to do it properly" involved reading my brother's cache of 1960s Practical Wireless magazines, dabbling a bit [my first 'real' radio was a homebrew 1S5 shortwave regen from a 1961 PW circuit, the valve came from a scavenging session on a rubbish-dump near Aberystwyth. On it I got to hear amateurs on 3.5 and 7MHz and that sealed my fate].

I was always a "theory-before-practice" type - so I avidly devoured the 'technical' pages of the likes of Wireless World. O-level Maths and Additional Maths enlightened me about the world of Algebra and Calculus that appeared in WW. Yes, equations, graphs - I was captivated - using this I worked out from first-principles the coils I needed to wind to get a 'grade 3' surplus Collins TCS12 receiver working again.

A-levels, Pure and Applied Maths and Physics - oh what fun! Turned out I knew more about electronics than the physics-master.

Then at university I leaped into the physics-department library (though I was studying bilological sciences) and there got hold of ARRL handbooks along with a bunch of orange-jacketed "Common Core" books which were full of circuits for things like thyratron-timebases, oscilloscopes, Dekatron-based counters and chopper-based DC amplifiers. I built quite a few 'odd' bits of electronics for measuring/analysing biological/neurological voltages.

University also got me in touch with US technical magazines - Electronic Design and RF Design brought news of cutting-edge developments in semiconductors and digital electronics, as well as computing. I was known to sneak into computer-science lectures which got me fluent in FORTRAN, ALGOL and CORAL-66.

"Elektor" magazine was also around then - I remember building their 'Junior' 6502-based computer [all 1KBytes of RAM, 1Kbytes of ROM] and programming it to convert amateur RTTY to proper ASCII which was printed-out on a borrowed-from-the-computer-department Teletype-43.

Then, after a brief period working for a State-sector 'research' organisation, I went freelance and specialised in 'doing the odd stuff' the big companies fought shy of. I've honestly always been someone who has an analytic approach to things - though enlightened by contact with the real-world, where 'stuff' needs to be on-time, within-budget, maintainable and - above all - profitable!
G6Tanuki is offline  
Old 14th Dec 2019, 7:06 pm   #92
Skywave
Rest in Peace
 
Join Date: Jun 2006
Location: Chard, South Somerset, UK.
Posts: 7,457
Arrow Re: Nostalgia? Probably.

Quote:
Originally Posted by Radio Wrangler View Post
. . . and set out to learn how to do it properly. As I learned more . . .
Quote:
Originally Posted by Skywave View Post
Perhaps you'd like to tell us about the path you took "to learn how to do it properly".
David: you replied; a fascinating story. Thanks.

Overall, my tale is similar, but it involved a lot of 'Government type' activity . . . if you follow my drift. The never-terminating requirements of the Official Secrets Act prevents me from going into details. A lot of that was fun, but not exactly well-paid.

Al.
Skywave is offline  
Old 14th Dec 2019, 9:47 pm   #93
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,801
Default Re: Nostalgia? Probably.

After Tanuki's post, I'd add that I got a lot out of Electronic Design and RF Design magazines. The library at HP got just about everything. I trawled through the literature output of Bell Labs, Marconi, Philits Techical Review, the HP Journal. All this was fabulously stimulating. Dudley Harwoods BBC speakers were there in their research reports.

On the amateur front there was the American Ham Radio Magazine which transmogrified into Communications Quarterly... I still take QEX

On top of these were the wonderful applications notes from National Semiconductor, Analogue Devices and others.

The key is to roam widely and wildly, don't stick to your own specialism. Roam. Widen your horizons. You'll never know where you'll bump into inspiration. It's rare stuff, and you wouldn't want to miss any.

Look at things from different directions until something clicks and you see simplicity.

Above all, have a sense of humour. Have fun. Be prepared to send yourself up.

A friend and colleague designed an audio amplifier trying to use the minimum number of stages and devices. He moved to Linn and went on to produce a variant of it. For a laugh, I did one trying to use as many transistors as possible, subject to having a demonstrable reason for each one. We built a small run of them at HP. We all had fun.

Back in the seventies there were draconian pay restraints, galloping inflation and serious misery. Engineers were fleeing the country. One budget day a bunch of the guys built a TV receiver out of a couple of spectrum analysers and a couple of scopes. Fun!

Bill and Dave approved of 'homers'. They knew how much people learned from them, and knew that it boosted the company's capabilities. Provided it was kept to sensible levels.

I enjoyed the firm while Bill and Dave had great influence, and I saw the wheels come off afterwards. I think I got to enjoy the best years ever there.

One of the other denizens of this forum was a project manager there and had wonderful loyalty from the people working on his projects. I never did, and I reckon that was my loss. He was certainly one of the best.

Oh, and I had some dealings with people of both military and spooky variety, and met them on their respective premises. They weren't anywhere near as secretive as the cellphone manufacturers were about their performance figures ;-). Before being made redundant (pretty much out of the blue) I'd been involved in reviewing all the plans for future spectrum analyser products, looking for something to use. This sort of info comes under the heading of company secrets and could do a lot of damage if it got out. Whatever you are involved in, there are things you do not reveal.

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is offline  
Old 14th Dec 2019, 11:00 pm   #94
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
Default Re: Nostalgia? Probably.

"Byte" magazine was also one of my must-reads - I always turned to "Ciarcia's Circuit Cellar" first, then looked through the ads for microcomputer systems, and marvelled at how - even then - US purchasers paid only about half what we had to pay here in the VAT-and-import-taxes-burdened UK.
G6Tanuki is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 6:40 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.