calling amp techs! - horizontal mounting of valves in rack cases

Do you have a drill and taps to make side post stand-offs (if you use metal)? I thought I saw a recent amp build here from Europe that used wood for stand-offs. You could use turret board material that would be easier to cut for the mount board.

 

As you probably remember, I used the mounting plates that Angela sells. You need a 2RU case to use them though. Most of the turret boards with pre-mounted sockets are the same way too, I think.

 

Some tubes require that they be mounted in a particular orientation. Audio tubes can be mounted horizontally or vertically. A tube's data sheet will specify how it can be mounted. If you mount a tube horizontally, you have to ensure that there is sufficient space around the glass envelope to ensure sufficient cooling. Usually not a big issue.

 

There are a few other eBay sellers pimping similar ones, like these guys.

I used some rubber washers in strategic places for vibration isolation, and left room for some other solutions for that if needed. Building that cage assembly was tedious but fairly easy, and hopefully provides a bit of shielding in the bargain. Home Depot carries all the channel and angle stock, but of course I have no idea about UK suppliers. Next time I will probably drill and tap most of the assembly rather than using stainless steel nuts and bolts. I'll see if I have some assembly pics of just the cage and tube mounting plates.

Edit: Here you go. #4 stainless nuts and bolts, lock washers and threadlocker, holes drilled through the channel stock. Eventually I drilled out all the cooling hole locations in the channel stock too.

 

They're out there, but I can't remember where offhand. Email Angela, he'll know. Another possibility would be the little prototyping boards Pete Millet sells. I'll probably look at getting small sub-circuit boards like that made myself eventually, but with solder connectors. That'd be handy for placing grid resistors as close as feasible to the tube pins, for example.

 

There are 9 pin right angle tube sockets at apexjr. They also sell octal relay sockets that have screw terminals. Can't beat their prices.

Antique electronics sells terminal boards for prototyping. These are sockets mounted on FR-4 board with turrets. They can be mounted horizontally or vertically.

Of course, what would be neat to have is something like this.

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PartsConnexion and many other places sell 'em too. Can't remember where I got this one:

 

I see that you have a (jensen ?) transformer mounted the same way. It's a nice easy solution. I buy FR-4 in 4 foot square sheets and have them laser cut it down to more manageable strips. They still need to be cut to size for whatever my needs are. But cutting these boards is no fun. It is hard on the tools and the fine dust is quite hazardous. Being able to buy small pre made boards that you could use in applications is well worth it.

I saw a nice printed circuit board being sold in England some time ago that had a single tube socket, traces for grid, plate, cathode components, and solder pads for input and output. A perfect general purpose module.

 

+1

I used to repair and/or modify windsurfing fins made from FR-4, it's quite nasty stuff to machine. And yeah, the Jensens with the 3/8" bushing mounts are a pretty easy format to work with. The wires are really fine and I don't want to have to de- and re-solder them directly much if I can avoid it.