Craig Sawyers

Heh - I could wish!

Power outages are good - makes you get back to the basics of life. Food, sleeping and sex - not necessarily in that order. And possibly a bit of booze thrown in for good measure.

You'll have great fun! Takes a while to stuff those monsters. Mine are finished now and all components are in. Just waiting for transformers and casework. Defluxed both boards a couple of days ago - quite a job given the size, but worthwhile since flux is not consistent with high voltage gradients long term. Even sprung for a set of four xf3 Mullard tubes and Pearl tube coolers. Means you can't see the glow, but reduced envelope temperature extends tube life by a factor of about 2 times, allegedly. Getting a woodie thinking about it Using the waiting time to get on with finishing off a stalled Blue Hawaii. Like most stalled projects this was down to casework. But Hammond have fairly recently introduced some really sexy 19" cases. Extruded side panels, black powder coated, everything 1/8inch thick, and with perforations on top and bottom towards the rear of the case - so right over the heatsinks. Rack mounting ears are separate and so can be removed. I've ordered one and will report back on how good it looks. I'll need a second one for the PSU of course. Their part number RM2U1913VBK.

It's reassuring that this phenomenon seems not to be a speciality of Leicester University. I'm sure it does not help with it being during vacation season - if the papers are in someone's in-tray and then they go for two weeks holiday - that is where the papers stay.

HR functions are a law unto themselves. I'm moving from a contract to a part time employed situation at a UK university. Contract ran out at the end of May. So we are now 7 weeks and counting. Progress has gone beyond glacial to geological. Don't expect to be in post until start of September - which means that a Euro14m multinational project has been without a Project Manager for three months. Go figure.

I remembered that my 1987 Lambdas came with a step-up transformer based driver. It connected to the output of a regular loudspeaker amplifier. The bias came from voltage multiplying and smoothing one of the output drive signals. Called an SRD6SB. I pulled it out the attic and took the lid off to see how it limited the bias, and what the voltage was. One of the headphone drive signals connects to a 100k resistor with a 100nF in series, with a 100V Zener to ground. So that limits the bias at that point. It then goes to a voltage tripler with 100nF caps, and a final 1uF across the output. Then a 4M7 to the diaphragms. So I reckon this unit provides a bias of 300V. The tolerance of the Zener is 10%, so the voltage could be between 270V and 330V. Seems a bit high as compared with the above, and circuit losses and leakage might limit the voltage to a bit lower. Might shove it on the sig gen and a random power amp and see what I get at the bias output.

Driving along on Monday with the cruise set to 85mph, I was passed by a monster black BMW or Audi land cruiser as if I was stationary. Reckon he was doing 140mph. His license plate was F1 ASH, arranged so that it spelt "FLASH". Oh dear oh deary me. What a clown. Anyway, justice was done - five miles later he had been pulled over by the police. Heaven knows how they caught up with him. He'll lose his license for sure at that speed.

That Michell and Webb Look. If you enjoy Brit comedy sketch shows, this is a must watch. Also, for total madness, Shooting Stars. Very oddly David Gest was on, totally bewildered about what on earth he had got himself into.

OK Inu - I'll bite. Where did you get those screws? What an amazing material.

That is serious good news!

Problem is I didn't notice who it was. This must have been fifteen years ago or more - long after The Frost Report, Python, Python movies, FT and his half way decent other movies (like Clockwise, Fish Called Wanda and Fierce Creatures).

It is amazing the major effect this series had - considering the fact that only 12 were ever made. Years ago, while trying to barge my way to my seat at a Jose Carreras open air recital at Hampton Court I pushed past a big guy while muttering "'scuse me...". When we got to our seat, my wife said "Did you notice that you just barged past John Cleese?". Oops.

Way to go! We've just celebrated 32 years - but you're precisely where we started out

Um - the sketch I had was misdimensioned. The official bush diameter of the 7721-3PPSG is 3.56mm and so should fit in a 3.6mm hole. Mine actually measure a tad over 3.6mm - so it takes a very firm push to get them home in the device tab. But they *do* go in.

Hokay - remaining outstanding items have arrived. 2SC3381 - check 4171G - check 7721-3PPSG -check Now - a question for Inu. How did you get the 7721-3PPSG to fit in the holes of the TO220 devices? Faced with the fact that they don't (for me anyway) I looked up the spec. Holes in devices = 2.6mm, bush diameter 2.85mm. Did you ream out the holes in your devices, or am I missing something?

That is really useful information - thanks. My Lambda's are 1987, so 250V as per KG's suggestion sounds like the way to go.

That is what I have gone for too. Getting all hot and sweaty now - just waiting for: Alumina insulators Long transistor bushes 2SC3381's Casework

Finally off-shelved a project - a Gilmore class A dynamic headphone amp. Did 90% of the work four years ago and then - ooh shiney. Even did board layout and procurement, and all the parts procurement (good job since getting the complementary dual FETs now is next to impossible). So building cost was next to nothing - just getting value from money spent four years back. Outboard dual power supply with two transformers. In the amp box a Borbely current regulator and four amps - currently wired as two stereo feeds from RCA in to two Neutrix headphone jacks. Expect to upgrade to go single ended in to bridged out (need two more partly-stuffed amp boards for that - no FET's needed) and full balanced in to bridged out switchable, switchable gains and DACT to replace ALPS blue beauty. But already sounds astonishingly good after warm up. Quickly came to conclusion that I prefer DT990 to K701 in most departments. Now on to the final build stages of KG's SRM-T2 - just need a few trivial parts on back order, and casework from Kevin.

Vicki - that looks exceptionally uncomfortable. I really winced at the bone-on-bone bit. Good luck with the options - but that they can now resurface the ankle joint sounds like a very positive development.

That sounds real neat. So one 5M resistor gets 560V and goes to the high bias jack, and the other resistor gets 250V which feeds both bias pins (shorted together) on the low bias jack?

Or turn beer into Marmite and put that on the toast - best of all worlds

Eek - I now realise I should've keep up to speed with software more. Looks like a burst of transmission line noise....

My wife did a math(s) degree at University with an excellent result. Left me standing - and I did every math(s) and theory option in my electronics degree. She then went into being an accountant, and now can remember absolutely no math(s) at all. There is probably a joke about that, but since she out-earns me by a significant amount I can't quite remember it

That is a disturbing image for sure