11 Set stuff

[cletrac (RIP)]

It's starting to look the part. I have about 7 hours into it so far. The ends on the wires that go to the set are offset almost half an inch so the terminals stick out about 1 1/4 ".
There's 4 bolt holes below the bottom gauge that must hold the condensers on the inside. Now to make the switch mounting plates.

[Ron Pier]

Great stuff David and thanks for the pictures you sent me. I'm dead interested in what you do with the doors. Ron

[Chris Suslowicz]

Originally Posted by cletrac

It's starting to look the part. I have about 7 hours into it so far. The ends on the wires that go to the set are offset almost half an inch so the terminals stick out about 1 1/4 ".
There's 4 bolt holes below the bottom gauge that must hold the condensers on the inside. Now to make the switch mounting plates.

Not wishing to rain on your parade, but the original unit most likely had a plastic (ebonite or Tufnol) panel with the lettering engraved on it. The terminals would be uninsulated and probably BA thread with all the (electrical) metalwork being nickel plated.

Chris.

[Grant Bowker]

Originally Posted by Chris Suslowicz

Not wishing to rain on your parade, but the original unit most likely had a plastic (ebonite or Tufnol) panel with the lettering engraved on it. The terminals would be uninsulated and probably BA thread with all the (electrical) metalwork being nickel plated.

Chris.

My measurement of the terminals on my 19 set switchboard (approximately 1/4-25) suggested BA threads and the 0BA nuts I ordered fit perfectly. Since a 11 set component should be earlier than 19 set, it seems reasonable to me that an 11 set switchboard would also be BA threads. My source for the 0BA nuts was http://www.britishfasteners.com/inde...0ba-steel-3665

[cletrac (RIP)]

Chris, in the instructions it says the captive screws holding the panel in place have to be tight because they form part of the electrical circuit. Therefore the panel must be metal. The only part of the circuit would be grounding for the two condensers that are attached to the back side of the panel.
Thanks for deciphering that part of the instructions.
Those lid catches have me scratching my head. They don't look to be spring loaded. Maybe that's why the bottom one in the picture isn't latched. Gravity took over. The catches must be made of spring steel to hold some pressure to not fall open.

[Chris Suslowicz]

Originally Posted by cletrac

Chris, in the instructions it says the captive screws holding the panel in place have to be tight because they form part of the electrical circuit. Therefore the panel must be metal. The only part of the circuit would be grounding for the two condensers that are attached to the back side of the panel.
Thanks for deciphering that part of the instructions.
Those lid catches have me scratching my head. They don't look to be spring loaded. Maybe that's why the bottom one in the picture isn't latched. Gravity took over. The catches must be made of spring steel to hold some pressure to not fall open.

I suspect the panel is plastic, simply because it would be a lot easier to manufacture that way, and be safer to connect up - touching a battery lead to the panel while connecting up would not cause a short circuit - also it would be more rigid than a thin metal plate. They tended to use uninsulated terminals in non-conducting panels a lot, also it allowed the labels to be engraved and paint filled, rather than having separate labels made and screwed on, and the screws on those cable clips at the bottom would have to go into tapped holes (because nuts on the back of the panel would be impossible).

The condensers will be the block paper type, with mounting lugs on the bottom and probably stud connections on the top.

I think the panel retaining screws have to be tight because there are connections via them between the case and the circuit - if you look at Figure 16 there's a wire to each side from the Regulator (left) and Set (right) negative terminals.

I have some spare parts and spare valve cases for the WS19 and WS18 with that type of retaining clip instead of the toggle clamp variety (also the "spring clip & stud" "hook and stud", etc. There were a lot of variations according to the different manufacturers).

Chris.

[cletrac (RIP)]

If anybody is looking for a counterpoise, this outfit has some for sale

[Mike K]

Originally Posted by Chris Suslowicz

Not wishing to rain on your parade, but the original unit most likely had a plastic (ebonite or Tufnol) panel with the lettering engraved on it. The terminals would be uninsulated and probably BA thread with all the (electrical) metalwork being nickel plated.

Chris.

Would a ebonite panel of that size, have enough structural strength ? With all of those holes for the meters and the terminal posts and the rest , a ebonite panel would be rather fragile and prone to cracking . Mike

[Mike K]

this may help .............

[cletrac (RIP)]

Plastic or metal? I was thinking along Mike's lines. Plastic in the late 30s stuff was restricted to small parts likely because of the strength issue. That panel is held in place by 2 bolts 10 inches apart and near the edges. The weight of the cables is all hanging off the panel too and would get flopping around in rough conditions.
Chris, have you got a picture of one of those catches?

[Chris Suslowicz]

Originally Posted by cletrac

Plastic or metal? I was thinking along Mike's lines. Plastic in the late 30s stuff was restricted to small parts likely because of the strength issue. That panel is held in place by 2 bolts 10 inches apart and near the edges. The weight of the cables is all hanging off the panel too and would get flopping around in rough conditions.
Chris, have you got a picture of one of those catches?

There's plastic and there's plastic. The Switchboard, Charging, No.5 used with the WS9 and WS19 is made from a single sheet of some black plastic and it's probably almost twice the area of the item under discussion. I think it's about 1/4" or 3/8" thick, and secured to two wooden battens (for mounting to the truck) by a couple of woodscrews.

I'll try and get some detailed measurements tomorrow, and photos of the catch (which appears to be spring brass on one of the spare valve cases for the WS38).

Chris.

[cletrac (RIP)]

Chris, you're right but did they have both those kinds in the late 30s? lol By the mid 40s plastic had advanced by leaps and bounds!
I got one switch mounted today. When I'm done and paint stuff black it'll look the same whether plastic or metal.
I've been pondering the construction of the doors. In our picture of them it almost looks like the edge of the left door is bent funny but I'm not sure. The light is coming from the right so the black line you see has to be the gap between the doors.
I'm going to make the doors out of 14 or 16 gauge. They wouldn't be heavier or they wouldn't need the edges folded back that inch or so. That open catch hangs down over an inch so it has to be mounted an inch and a quarter or so back from the face of the closed door. That makes the door an inch thick. The doors will look like a shallow box.The doors don't overlap the unit's sides or they would tangle with the hool up cables.

[things_green]

Originally Posted by Mike Kelly

Would a ebonite panel of that size, have enough structural strength ? With all of those holes for the meters and the terminal posts and the rest , a ebonite panel would be rather fragile and prone to cracking . Mike

interesting thread, superb job on your recreation David.

I have a portable charging switchboard Mike, very heavily cutaway for the rheostats & meters.
I don't know if its ebonite, plastic, paxoline or something else?
no sign of cracking since '40, or is that '41.
the facia measures 14 1/2" x 15 1/2".

[Mike K]

Originally Posted by things_green

interesting thread, superb job on your recreation David.

I have a portable charging switchboard Mike, very heavily cutaway for the rheostats & meters.
I don't know if its ebonite, plastic, paxoline or something else?
no sign of cracking since '40, or is that '41.
the facia measures 14 1/2' x 15 1/2".

Brent

hi, that item of yours looks to be in mint cond. It may have been stored and never used .Did you restore it ?

Don't know what it is for ???????????

[things_green]

Originally Posted by Mike Kelly

Brent

hi, that item of yours looks to be in mint cond. It may have been stored and never used .Did you restore it ?

Don't know what it is for ???????????

'portable' charging switchboard. For charging 3 batteries at once...use the rheostats to tune the voltages. I have a 4Kv Coventry Climax genset I'm hoping to use it with. someday ;-)

It was pretty careworn when it arrived.....
I sourced to correct volt meter from my spares (after looking around the planet for 12 months ~doh~). Still requires a 3rd cut-out relay.

[Chris Suslowicz]

Originally Posted by things_green

'portable' charging switchboard. For charging 3 batteries at once...use the rheostats to tune the voltages. I have a 4Kv Coventry Climax genset I'm hoping to use it with. someday ;-)

It was pretty careworn when it arrived.....
I sourced to correct volt meter from my spares (after looking around the planet for 12 months ~doh~). Still requires a 3rd cut-out relay.

Hi Brent,

The front panel will be made of one of the "Tufnol" varieties, and is basically Synthetic Resin Bonded Paper or Fabric. The resin is phenol/formaldehyde and is a thermosetting plastic that is cured by heating with the material in a press. (Basically it's Bakelite with paper or fabric reinforcement and is a good insulator and very strong (in the thickness used for that panel).)

That charging switchboard is meant for a 550 Watt generating set, so your 4KVA one may well cause the magic smoke to escape. They operate by using one of the rheostats to control the generator field current and hence the output voltage produced, and the other three to set the charging current for each of the output circuits - so you can charge different types of batteries simultaneously provided each circuit has the same total voltage rating and all the batteries in a circuit have the same amp hour capacity.

You could ignore the voltage control rheostat and use it with a suitably chunky variable DC supply, say 18 volts at up to 30 amps for charging 12V signals (or other) batteries.

Do you know which accumulator cut-out you are missing? I picked up a couple at a radio rally recently, and while they are fairly heavy, surface mail should not be too expensive, even to the other side of the planet.

Chris.

[Mike K]

Originally Posted by things_green

interesting thread, superb job on your recreation David.

I have a portable charging switchboard Mike, very heavily cutaway for the rheostats & meters.
I don't know if its ebonite, plastic, paxoline or something else?
no sign of cracking since '40, or is that '41.
the facia measures 14 1/2" x 15 1/2".

here is one like yours Brent 9.25 on the movie

https://www.awm.gov.au/collection/F05239/

[things_green]

Originally Posted by Mike Kelly

here is one like yours Brent 9.25 on the movie

https://www.awm.gov.au/collection/F05239/

nicely spotted Mike, thanks ....great to see the kit in use....
love that kick start on the genset!

Brent

[cletrac (RIP)]

It seems odd that the morse key originally had a red and black wire to hook it up when everything else used that drab greenish colour. Here's my key with those wires attached. They're about 2 feet long which is what they call for.
The wave meter had those two spare valves with it. The bigger one is the same as one in the set but the smaller one doesn't have a counterpart unless it's for the vibratory unit that I don't have. It fits in the spare valve case. I'm missing the lid too.
The correction chart has Oct 1, 1940 on one side and March 30, 1943 on the other side. Seeing as how the 11 set was the most modern unit this wave meter was used with, I guess the Brits were still using them for training in 1943.