I was wondering where I may be able to get some schematics in Visio or other program for a variety of my tubes. I want to draw the schematic before I replace some of the old caps.

Anyone know where???

There are several ways of going about that. Do you want to do something like a cut & paste of the image of the particular tube: As in a scan

What I have, is a now obsolete, AutoCAD program, for which I bought an optional electrical symbols library, which included some valves descrete component, switches etc.

Of course, being an AutoCAD, it can also create the missing & draw the entire circuit ( Silicon Chip August 2009 P92).

My normal tactic is to "place" the valves, coils & Transformers, as they are on the chassis & then play "join the dots". If you can get a circuit it is much easier. The EMMCO in SC did not have one.

There is normally not much of a variety of valves in a 5 Valve radio. eg. A Pentagrid, A few Pentodes, perhaps a Triode one of which may have diodes in it and a double diode rectifier.

Marc

I use the free program TinyCAD. It's far from being the be-all and end-all of drawing tools, and it does some things in weird ways, but it's good enough for the stuff I do and it's not hard to use. Its user manual is pretty good and there is a user forum.

It has only pentode and triode in its standard symbol library, however it's a pretty straight-forward task to create your own symbols using circles and lines and save them in your own library.

http://sourceforge.net/projects/tinycad/.

Looks interesting; As I have two AutoCad programs on the system, I see no need to download.

What format does it save in? and can you add symbols to it? The basic one of what I have will allow you to make & save items to its Libraries.

With a small amount of messing about, I can take what I have drawn and transfer it to formats like bitmap & wmf

Marc

Files are saved in internal format with .dsn extension.

As I mentioned, you can create your own symbols.

TinyCAD can supposedly export to PCB layout software however I haven't tried that feature. I usually print to PDF.

For a freebie it's not too bad, but if I were a serious designer and PCB prototyper I'd definitely invest in professional tools.

AutoCAD will set you back a few bob. It's worth it if you use the available power though. I used to know my way around it but when trying to use it about six months ago I didn't know where to start. It's been many years since I last completed a job with it.