Here is a list of all the postings Nicholas Farr has made in our forums. Click on a thread name to jump to the thread.
|Thread: Replace Speaker Surrounds|
Hi MichaelG, I think I read something very much the same as you say about valve amp distortion, several years ago, but it was a fair while after I built my stereo valve amp that I used doing my Discos, the design was from a Babani Press No. 12 paperback and it was a design based on the "G.E.C. 912-PLUS" B.P. No 12 (Worldradiohistory.com) ( Chapter 3, page 23) It could be driven very loudly without any significant noticeable distortion and had a good overall sound. At the time I built it, I couldn't get a transformer with the power requirements for the HT and the valve filaments, so settled on a transformer for the HT through a semiconductor bridge rectifier with a non split phase output, and a separate transformer for the filaments. It got stood out it the garage after I was no longer doing Discos and suffered a bit of damp which got into the speaker output transformers and corroded some of the fine wire coils, had no reason to repair it by then and the wooden cabinet was also shoot by then.
Hi, Dave, never did like graphic equalisers, bass and treble always better in my opinion, but as you say no common setting as everyone's hearing and taste is different. I did a repair on a workmate's brother's Yamaha natural sound amp once, that only had a volume control and it's sound didn't suite my taste at all, but he of course thought it was the best you could get and was over the moon when I fixed it.
|Thread: Macc Models Excellent service|
Hi, ordered three lengths of brass rod around mid afternoon yesterday, postie just dropped them off to me a few minutes ago, can't expect much faster than that.
|Thread: Replace Speaker Surrounds|
Hi Neil, probably would make a good subject down the pub, but I rarely go to any these days, the nearest one to me is in the next village which is over two miles away on an unlit winding country road with virtually no footpaths and I don't drink and drive and the cost of a taxi is out of the question, even during BST, it's not a road I'd want to plod along after a few beers. Much better to have a glass or two of wine and listen to some music in comfort at home.
Like your the idea of using the B&Q shelves for enclosures, but not planning on making any sort myself, I've got a mini stereo system in my garage, a fairly compact system that I inherited from an aunt in my kitchen and a Sandstorm STBTR14 rechargeable portable speaker with Bluetooth that I can use with my Walkman MP3 anywhere.
Hi MichaelG, sounds as if they were going for a song. Oh! there might be a pun in that!
|Thread: Lathe identity|
HI Tom, have a read of Posting pictures etc.
Welcome to the Forum.
|Thread: That Strange Calculator Again|
Hi Nigel, well if the red and yellow ones are holding gears or maybe little dogs to prevent it being turned anti-clockwise, it would make sense of their random looking positions and the blue and green ones that Martin suggests make logical sense. Not always easy to see depth when it's just a flat picture. Thanks for your replies.
Hi, I have also noticed the 0-9 twice on the outer ring and wonder if they represent the tabulations at the bottom right, which only go up to 9 and 0 representing, well! I guess most people would take it as 0. The other thing I'm curious about is what look to be holes that I've arrowed in blue, green, red and yellow, the blue and green one alternate all the way round, maybe windowed cards or something like pointers, are pegged into them to give the answer to whatever this gadget may solve.
|Thread: Replace Speaker Surrounds|
Hi Neil, looks like good gear and the way they are stacked reminds me of days in the early to mid 70's, when going to see some of the top bands of that time, playing in our local Corn exchange, one of which was Status Que who I saw twice, their stacks of WEM speakers and 100W slave amps, on both side of the stage, were quite impressive, there were others like Hawkwind who I saw a year or so after their Silver Machine release and Wizzard, who were extremely loud but worth the attendance, but I can't remember the gear either of those used. Many of the bands used Marshall gear and some had Orange. Like your the guitars, I did have a bass guitar once as I do like a good bit of bass, but soon found out that I could never get the hang of playing it, so I sold it and bought a CB radio when they were all the rage.
Now I'm not embarking on a battle of speakers or anything, but I do have a fondness of them and here's a photo of my left hand cluster, which together with the right hand side, contain 18 speaker units in all, which are all driven with a Technics SU-3050 amp but this is not to make the loudest sound possible, although they can be deafening, but the speakers may well all cover the same frequency, but produce some different tones, or a colouration of the sound if you like, and one song I like to play fairly loud through them, because I really like the guitar work, is Tina Turner's "Better Be Good To Me" which to me brings out every aspect of the guitars sound and how it's played and I think it really feel as if I'm listening to them as a live performance.
In the cluster are my Axiom 401 Disco cab on top of which are Fane J44 horns which also contain the crossovers for 4 or 16 ohm configuration, the cream one with an Axiom 10 and a MCM Audio Select: 53-1080 tweeter with crossover inside and fixed at 8 ohm, on top of which is one of a pair of Dynatron three speaker system with crossovers inside at 8 ohm, which were given to me many years ago, these are connected in series to produce 16 ohm configuration, which in conjunction with the Disco cabs and horns at 16 ohm give a load to the amplifier within the minimum allowed. The amp will allow all speakers to be used, or just the main Disco cabs & horns alone, or the Dynatron & cream ones alone. The Disco cabs can be used without the Fane horn and crossovers if so desired, by just connecting straight to them.
Here is info of the Technics SU-3050 amp. (audio-database.com) for anyone who it may interest.
Hi, I relined my disco cabs with new and better quality acoustic wadding back in 2019, what I put in them when I first made them was a cheaper compromise as the better stuff was quite expensive back in the early 70's. My late brother and I, bought the loudspeaker units at a special price of £12.50, which were advertised in Practical Electronics by G.W. Smith & Co (Radio) Ltd. in Tottenham Court Road London, they were advertised as Goodmans Axiom 301, but were actually 401, we got a couple of new Garrard SP III decks for £10.25 each as well while we were there.
At the same time as renewing the acoustic wadding, I decided to take off the front grills to inspect the cones and the surrounds and clean any dust that may have accumulated, but after 47 years they were still in good order.
They still sound good after nearly 49 years and are improved by the new wadding, just sad that my late brother never heard a sound from them.
I though these cabs I knocked up, supposably temporary, were rather crude Neil, these contain a twin Axiom 10 but I had to replace the cheaper tweeters units awhile ago as the one in the other cab lost its voice.
These were made in about 1987 from some ex-display panels from various dismantled units and a fair amount of other off cuts from Texas, which became Homebase, but they sound good also, so I guess that's why I've never made any better looking ones and although there's a chunk broken out of the tweeter part of cone, it doesn't seem to effect the sound, one will have to excuse the gutter bolts holding the main unit in, as that's all I had which were long enough at the time.
Edited By Nicholas Farr on 11/01/2022 23:39:43
|Thread: Engineering as Art|
Hi, I have never worked from an original drawing in all my working life, in my old job the drawings were done on translucent paper with a border and an information box in the lower right hand corner, below is a photo of a small portrait one.
Once the drawing was completed and checked, it would be fed into an A0 copying machine which had a roll of Diazo paper, which was sensitive to ultra-violet light. The drawing was driven through on top of the Diazo paper under ultra-violet fluorescent tubes, which the light would only pass through onto the paper where there where no lines of the drawing and then the exposed Diazo paper would pass through an ammonia vapour which would develop the drawing, which would be used in the workshop, the original drawings been keep flat in purpose made draws in the drawing office.
I do have a couple of old drawings that were done in a similar manner I guess, this seems to be a two part copy paper where a master copy paper was made, the three photos below show a portion of a tracing from an original drawing. I don't know how the process worked, but I guess the original drawing was placed on the two part paper, the top part being translucent and the bottom one being sensitive ink, which would stick to the translucent one and produce a master copying print, which could then be copied onto a working drawing over and over again. The photo below show the translucent copy, a negative copy and a copy for the workshop. These were not made by the company I worked for, but from a company that supplied narrow gauge wagons.
The info box shows some dates when this was done.
In later years, this type was superseded by Auto CAD and ink jet printers.
Edited By Nicholas Farr on 11/01/2022 15:17:37
|Thread: Boxford chuck|
Hi Eddie, the back plate should be machined on the lathe that you are going to use it on, for the best trueness.
|Thread: Highway Code|
Hi RMA, I haven't ever seen an Amazon van deliver to mine, it's usually some old white van that belongs to the driver, many of which shouldn't be delivering to mine either as it should have been someone they passed a quarter of a mile away, some of them seem to come in their own cars even.
|Thread: Another old ME article required please|
Hi Ken, while I was scanning I see Ady 1 has posted the two pages, but I've put them on a single sheet that you might like to save or print out onto an A4.
|Thread: Engineering as Art|
Hi, a draughtsman is a skill in itself, so if that's what you what, expect to pay for it. In my old job from years ago, they had a very good one on our site who answered to central engineering and he had the job of drawing up for a large new processing plant, however once the plant was in production and thereby needing routine maintenance periods, it soon became apparent that things like lifting beams didn't line up with the central aspects of equipment that had to be lifted out by overhead hoists and you can imagine the name calling he got, but the plant worked with very little snagging problems from the start. I spoke to the draughtsman about the issues of the lifting beams not being in line and he produced his first overview of the plant showing how they were all in line and I then asked, well what went wrong then and he told me that the bean counters were happy with everything except the footprint of the building and was told to keep every thing inside it, but the building had to be 3.6M less in its width and so he had to compromise on the lifting beams and a few other things that didn't effect the efficiency of the plant's production.
|Thread: Highway Code|
Hi Nigel, yes it was all above board.
Hi, I agree with Robert about speed limits for commercial vehicles, but a lot of people don't seem to know it or they blatantly ignore it. UK Speed limits and I've seen them in the outside lane of 3 and 4 lane motorways with a trailer and caravans.
I've never towed a caravan, but have towed my own and other trailers during my day jobs, but the largest one I towed was a six wheel all steel flat bed one weighing 1 Tonne and was around 5M or so long and had 2 Tonnes of steel weed screen sections on and had to take it via Boston in Lincolnshire up to a little place called Strubby which is not to far from Mablethorpe, the A16 wasn't to bad, but the A1104 was a bit of an experience with such a long heavy load behind a Navara pick up and I had to do it twice. (but not on the same day)
|Thread: drill sharpening jig or dedicated tool|
Hi Jon Hill 3, this free Drill Sharpening Jig plan might interest you, although the construction notes are in MEW 17.
|Thread: Lock nuts / Jam nuts - MEW 311|
Hi, I'm with AStroud here as far as steel structures are concerned, friction grip bolts is what I was taught during my fabrication and welding technicians course.
As far as bolts that are just in tension not needing a locknut, the four bolts holding the spring steel laths between the motor plate and the tube on these vibrating conveyors, always had to have two nuts of the same thickness, the bottom nut was torqued up to full load and the top nut was then locked on, but both bottom nuts on each block had to be fully tightened before the locknuts were put on and this was the only way to be sure they would not come loose, in fact the motor plate and or the laths would fail. Only knew one failure of the bolts due to someone who decided to use a pair of Nyloc nuts, one on each bolt, which came slightly loose, which made two or three of the laths and the spacers to rattle enough to cause enough heat to spot weld them together in several places and the noise it produced was horrendous and I even had to cut the bolts off to replace all the laths and two new bolts, a single nut on the bolts would not stay tight.
Edited By Nicholas Farr on 07/01/2022 20:27:57
|Thread: Summer 1990 Rotary Table|
Hi Dr. MC Black, glad you find the photos better. I was not offended about your comments. Those scans were done many years ago and PDF editable programmes cost more than I was prepared to pay and the idea of the overlapping the sheets, was so that anyone could print them out on an A4 printer, trim a suitable side and attach to the next page and thus produce a drawing of the same size to that of the originals. Being there were a large number of these various plans, they were did this way to produce something useful and I could apply the same template to every drawing, they still took a fair amount of time to scan, as each side had to be scanned from both ends and then stitched together and then each scan had to be cropped four times to produce the separate pages. You can produce a decent size drawing onto a A3 sheet of paper, using the full scans, but of course they will be only a little over 50% the size of the originals.
Edited By Nicholas Farr on 07/01/2022 11:15:32
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.