26-08-2015, 08:11 AM
Like Tevor, I too am worried. Heatshrink over a high power reisstor is a very bad idea. If the resistor gets really hot as they are designed to do the heatshrink won't survive. At best there will just be a nasty smell, at worst it may not be as flameproof as you hoped.
Fuses look simple but are a complicated subject. A 1 amp fuse doesn't blow at 1.1 amp. The more current you take, the quicker it blows. This page will tell you a lot more than you need to know: http://wiki.diyfaq.org.uk/index.php?title=Fuse The important point is that fuses will not protect against small, long term, overcurrent.
In many cases there's no problem if you replace a valve rectifier with silicon diode(s) and a resistor. Yes it can stress the capacitors in the set more than a valve because full HT is available immediately power is switched on and before the valves start to conduct and drag the HT down a bit. Yes you can get higher curernts through silicon under fault conditions. Thes are often acceptable risks. We're here to help you make sensible judgements.
You've clearly been struggling a bit with soldering. We all had to start somewhere and I'm sure most of us made a hash of it at first. Presented with a crowded chassis, wires wound round tagstrips and old solder it can be tricky to do a good job. It can be hard to melt the solder at all at first. One trick is to run a small amount of new solder between the iron and the old joint. Once the old joint is fully molten you can use a solder sucker to get rid of a lot of the old solder. To save disturbing a possibly delicate tag such as on a valveholder you can remove a component by cutting its leads near the body of the component. Since modern repalcements are usually smaller it's then quite easy to join thenew component to the old leads. The purists can make some very neat mechanical joints between new and old leads. I'm not a purist
As I said earlier, we all had to start somewhere and we've all made mistakes. Those of us who are still here obviously didn't make any fatal ones
We like to help those who are less experienced but it can be hard to do it from verbal descriptions and even from photos. There's nothing like learning directly from somebody with experience sitting next to you but this isn't always possible.
Fuses look simple but are a complicated subject. A 1 amp fuse doesn't blow at 1.1 amp. The more current you take, the quicker it blows. This page will tell you a lot more than you need to know: http://wiki.diyfaq.org.uk/index.php?title=Fuse The important point is that fuses will not protect against small, long term, overcurrent.
In many cases there's no problem if you replace a valve rectifier with silicon diode(s) and a resistor. Yes it can stress the capacitors in the set more than a valve because full HT is available immediately power is switched on and before the valves start to conduct and drag the HT down a bit. Yes you can get higher curernts through silicon under fault conditions. Thes are often acceptable risks. We're here to help you make sensible judgements.
You've clearly been struggling a bit with soldering. We all had to start somewhere and I'm sure most of us made a hash of it at first. Presented with a crowded chassis, wires wound round tagstrips and old solder it can be tricky to do a good job. It can be hard to melt the solder at all at first. One trick is to run a small amount of new solder between the iron and the old joint. Once the old joint is fully molten you can use a solder sucker to get rid of a lot of the old solder. To save disturbing a possibly delicate tag such as on a valveholder you can remove a component by cutting its leads near the body of the component. Since modern repalcements are usually smaller it's then quite easy to join thenew component to the old leads. The purists can make some very neat mechanical joints between new and old leads. I'm not a purist
As I said earlier, we all had to start somewhere and we've all made mistakes. Those of us who are still here obviously didn't make any fatal ones
We like to help those who are less experienced but it can be hard to do it from verbal descriptions and even from photos. There's nothing like learning directly from somebody with experience sitting next to you but this isn't always possible.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
