TW Express perfboards available

[ampkits]

Hi there,

I am trying to standardize mtg holes of the power supply board for the chassis.

what concerns me is the actual dims:

If we have .265 spacing (I assume c to c), then with 17 spaces in the width, thatd be about 4.5" only (plus about .265/2 for each end for ttoal width of about 4.77). Is the board 5" exactly, or slightly less?

Another thing to note is: In the originals, the position of the mtg screw for the PS board seems to be underneath the transformer.

How do you guys do this? The hole can be counter shrunk I guess.

Or perhaps, due to the mounting clamp in the original transformer, this was not the case.

I think it should be noted that for OTs with thicker core, and doesnt use the widely extended clamp as per original, OT jutting out at the back could be a possible problem.

Thanks!

Nik

[dms]

Hi - I have been trying to find this NTE part - the 1k 25W that Mouser has is by Xicon, and it is much, much larger. Just talked to them last week, and they confirmed that they only have the Xicon.

Thanks, Davids

[Allynmey]

Hi - I have been trying to find this NTE part - the 1k 25W that Mouser has is by Xicon, and it is much, much larger. Just talked to them last week, and they confirmed that they only have the Xicon.

Thanks, Davids

Hi David, try
http://www.youdoitelectronics.com/
They have them and thats where I bought mine. They don't have an online ordering. Just call and they will ship it out. They are an NTE distributor.

Allynmey

[UR12]

Hi there,

I am trying to standardize mtg holes of the power supply board for the chassis.

what concerns me is the actual dims:

If we have .265 spacing (I assume c to c), then with 17 spaces in the width, thatd be about 4.5" only (plus about .265/2 for each end for ttoal width of about 4.77). Is the board 5" exactly, or slightly less?

Another thing to note is: In the originals, the position of the mtg screw for the PS board seems to be underneath the transformer.

How do you guys do this? The hole can be counter shrunk I guess.

Or perhaps, due to the mounting clamp in the original transformer, this was not the case.

I think it should be noted that for OTs with thicker core, and doesnt use the widely extended clamp as per original, OT jutting out at the back could be a possible problem.

Thanks!

Nik

Hi Nik

The length of the PS board is actually 18 holes long not 17. If you add .265/2 on each end then that comes out to 5.035 inches. The widest part of the board is 13 holes wide which equals 3. 445 inches adding the .265/2 for the edge you get 3.71 inches. There are 6 mounting holes in the PS board and they are a couple that are offset and not on the corners but one hole up or over. I only use 4 mounting screws on the PS. The clips that Ken used instead of turrets hang down about 1/4 inch from the bottom of the board and he probably use 6 mounting points to make sure if the boards flexed it couldn't bottom out on the chassis and ground out.

You are correct regarding the mounting screws being 'underneath' the transformer. I just use a counter sink head screw under the transformer and it works great. If you use the same metal standoffs that Ken used, you can remove the PS board without having to remove the transformer so this shouldn't be a problem. I have not seen anyone using the wooden spacer that Ken used to help stiffen the chassis so that the transformers dont warp the chassis. I am planning on using this on my clone along with a bottom plate. I am not sure I would worry about putting this hole n the chassis as I haven't seen anyone using this setup in their clone. They could always drill this hole themselves if they wanted to go that route. It might be nice to have a flange bent in on the front and back of the chassis to accomodate the screws for the bottom panel if someone chose to use one.

The spacers I am using are Mouser part # 534-1450C Keystone Spacers and 1/4"X1/2"SPACER,HEX

The Xicon 25 watt resistors should work fine as they are about the same phyisical size as the NTE part. here is a link to the mouser site that has the dimentions.

http://www.mouser.com/index.cfm?&handle ... 0&crc=true


Hope this helps!

[ampkits]

Hi Dana,

Well, sorry. But it doesnt make sense.

There are 18 holes, so there are 17 spacings of .265.

This will give about 4.505.

Add .265/2 x 2 for each end = 4.77

I know this is splitting hairs here, but it does affect the thing terribly since the mtg holes are so close to the tranny bottoms.

The only reason is I'd like to have the chassis pre-cut with the PS board mtg holes, so that people can buy the original look boards and do not have to drill.

As for mtg screws, yes not all is required to be there. It's sturdy enough with 4.

Attached is a grid drawing with spacings mentioned.

Thanks!

Nik

Notes:

In original, 9.1K resistor side has less board left than the other side. I have about .1972 here. So 3.7 is close.

[UR12]

Nik


Oh I see what you mean regarding the spaces. I just finished a batch of boards and decided just to measure them.

The length measured 4 7/8"
The widest part of the board was 3 1/2"
The width from offset was 3 1/4"

That's about as close as I can get with a ruler.

If you go with the specs on your drawing, I think that should work fine.

[ampkits]

Hi Dana

Cool.

OK, that should work, provided spacings of the mtg holes relative to each other is standardized.

Please see drawing attached. Is this about same as with yours?

Thanks!

Nik

[UR12]

Nik

The only thing I have to measure with is a ruler, but the picture and dimensions look good to me.

[hot_tube_tone]

Dana,

I got the boards and they look great. Thanks!!!

[UR12]

Glad they made it OK. Best of luck with your build and make sure you post some pics

Dana

[Jeph]

Dana, got mine the other day too. Nice work! I'll be taking pics and posting as I go.

[Chris G]

Hi Dana,
My Boards arreived today!!!!! They look great,You do a realy nice job on them for sure.All I need to re-due the Express is some caps and wire and I'm all set to go!!!
Thanks again Dana!!!
Chris G

[UR12]

Hi Dana,
My Boards arreived today!!!!! They look great,You do a realy nice job on them for sure.All I need to re-due the Express is some caps and wire and I'm all set to go!!!
Thanks again Dana!!!
Chris G

Chris

Glad you like the boards and they arrived OK. What caps are you planning to use?

[Chris G]

Hi Dana,
My Boards arreived today!!!!! They look great,You do a realy nice job on them for sure.All I need to re-due the Express is some caps and wire and I'm all set to go!!!
Thanks again Dana!!!
Chris G

Chris

Glad you like the boards and they arrived OK. What caps are you planning to use?

Hi Dana,
I will be useing the sprague atoms..........I was looking over the chassis tonight,I may opt to go with a new one.........I'm off alittle in a few spot's (v3) is to far left...... I just want to get as close as I can.......I see all the great work being done here and it makes me want to get as close as possible!!!!

Do find any difference running 3x 20uf and 3x 40 uf as opposed to 3/ 20's 1/40 2/30's as in the original?

Thanks
Chris

[keithrick]

Dana,
Thanks! I got my boards today! I will populate it over the weekend Great work!, populating the turrets was a pleasant suprise, and time saver! Thanks again.