I guess it had to happen eventually, yours truly manages to accidentally short the output and blow the fuse.
No problem, just fit another I hear you say. But this fuse is special. Typical. It is a 250mA Belling-Lee, it is 15mm long and the end caps are slightly smaller than a standard 20mm type.
Of course, I don't have one, so I did the next best thing. I broke open a standard glass 250mA 32mm type and nicked the fine piece of fuse wire to replace the vaporised one in the small fuse. In the lower picture, you can see the end caps and they have the fuse wire soldered through tiny holes in the cap. Using a magnifier and tweezers, I was able to perform keyhole surgery and now have a good fuse !
To understand the black art of electronics is to understand witchcraft. Andrew.
Been there and done that before, though not on anything special. Well done on taking the initiative and making a professional fix.
Thanks Marion,
There happens to be some on ebay, but not exactly cheap. I may order one sometime though. I did think of changing the panel mounted fuse holder to a 20mm type, but the hole would need drilling out to a larger size plus it is too near the chassis edge to accept the new holder anyway. It is just in front of the GZ34 .......
To understand the black art of electronics is to understand witchcraft. Andrew.
Hi Andrew,
I think it should be left alone, and then, how often do you plan to 'blow' a fuse? Given the relatively easy fix you just used, it's hardly worth all that extra work to modify the existing set up.
This reminds me of a Honda E300E generator we once had, and used a Honda specific fuse - that's where I did the repair job I mentioned above, but at 5A it was hardly special, just Honda wanting you to buy their fuses at about £3 each (at that time).
Marion
Ack, those things! Just needs a fuse, pop it out, what the...
Rips it out and fits a standard 20mm holder, job done.
...time passes...
OK, just need a panel mount fuseholder to finish this, rake rake here's one. Get it fitted, grab a 20mm fuse, why wont it fit, oh right I remember now.
Belling-Lee "OO" fuse, IIRC. About the same size as a BS 546 fuse, 5/8" long (or 15.9mm if you must.)
Might have some of those in the store...
Belling-Lee "OO" fuse, IIRC. About the same size as a BS 546 fuse, 5/8" long (or 15.9mm if you must.)
Might have some of those in the store...
Something at the back of my mind tells me this size of fuse was used in the wall outlet for electric clocks?
To understand the black art of electronics is to understand witchcraft. Andrew.
Posted By: PYE625
Something at the back of my mind tells me this size of fuse was used in the wall outlet for electric clocks?
The BS 546 fuse is indeed used in clock outlets. It was also used in some MK dimmer switches and it is also used in MK's fused BS 546 plugs.
Tonight, I fitted the new 5K multi-turn pot that came today. It was rather fiddly as it is mounted under some components that had to be removed to get to it, but all done now and the set volts can be adjusted finely and without noise or the output bouncing around.
I know a PSU doesn't exactly tickle the interest of many, but it is something different and I'll find it useful, plus I have enjoyed bringing it back to life.
To understand the black art of electronics is to understand witchcraft. Andrew.
I know a PSU doesn't exactly tickle the interest of many, but it is something different and I'll find it useful, plus I have enjoyed bringing it back to life.
On the contrary Andrew, it made an interesting change. I have a 'scary' PSU buried in a store that seems to be a dual one - good for 400V, with four meters on the front! Pass elements seem to be 6Y6s...?
Now that sounds like a PSU worth a visit !
6Y6..... http://www.r-type.org/exhib/aad0065.htm
To understand the black art of electronics is to understand witchcraft. Andrew.
Now that sounds like a PSU worth a visit !
That's the thing: there's loads of them in the PSU (at least four) and I think they're in series to get the volts up - look at the spec of the 6Y6. That would make a very loud AA5!
Here's a couple of old photos of said PSU.
It'd probably be worth more if I binned it and sold the 5U4Gs in it... but we don't do that here, do we?!
Looking at the plan view, the 5U4Gs are self-evident. Then there are four valves in a row - these are the 6Y6Gs. The octals are, I think, double triodes. One of those miniatures is a gas voltage stabiliser, the other I can't remember.... and it has no maker's name, and it weighs a ton!
Now that sounds like a PSU worth a visit !
It'd probably be worth more if I binned it and sold the 5U4Gs in it... but we don't do that here, do we?!
No we don't.... it's one of my pet hates to be quite honest. It happens with the better radiograms, but that's another story I could get hot under the anode about.
That PSU is well worth the effort in bringing back to a functional life.
To understand the black art of electronics is to understand witchcraft. Andrew.
Just a little update, I have been measuring the noise on the output and it is pretty quiet at 0.5mV ripple off load, and only 0.7mV with full DC volts and 150mA load applied. Unable to detect anything else noise wise, no RF or any other rubbish.
Bet you will sleep better now, knowing that. Hehe.
To understand the black art of electronics is to understand witchcraft. Andrew.
Swapping the ECC81 and ECC83 around makes little difference and it works just as well with two 81's or two 83's.
Wrong ! It may appear to work the same as far as the DC output is concerned, but the ripple noise on the output is quite a bit worse unless the correct valves are in the correct position. It must be to do with the differing gains between the types.
To understand the black art of electronics is to understand witchcraft. Andrew.
It’s a very well designed device, it would have been expensive when new.
Frank
It’s a very well designed device, it would have been expensive when new.
The mystery is what was it intended for? Not a general purpose PSU surely ? Was it meant for something in particular I wonder, as part of a larger item, or a group of them in an installation of some kind? We may never know.
To understand the black art of electronics is to understand witchcraft. Andrew.
