Source for red fiberboard in quantity

[lastwinj]

mcmastercarr.com has a decent selection of fr4/g10 circuit board material. also try searching for garolite, or paper phenolic.
try paul ruby. he uses the red swirl fiberglass on some of his boards. he might tell you where to get it.

turrets? keystone from mouser has the best prices. other manufacturers? cambion, mill max, concorde.

germ

[cloudhopper]

Germ, you mention paper phenolic, I have a large piece of paper phenolic I was going to use for circuit cards until I read about "tweed disease" where the phenolic picks up moisture and changes to be conductive and/or capacitive. Have you or anyone else heard of this? I decided not to use the phenolic out of fear of future problems with it.

[nigelb]

Yes I have heard of this, and experienced it. I have several big sheets of RS Components Tufnol, similar but cloth based rather than paper, which I cannot use because it is electrically leaky. The problems I was getting with three of my amp builds was noise and scratchy pots. I tried all things to get rid of it, three brands of pots, wiring, screening etc. etc until I discovered standing DC of 4-5v on the pots. It wasn't until I happened to probe an unused turret, nothing connected, on the board and found a standing voltage of 17v that I cottoned on to what was happening. On an unpopulated board I was getting leakages of 10 to 22 Meg between various turrets.

I made a board out of FR4 board and it was fine. I now have proper PCBs (sacrilage I know) made for my amps with tracks, silkscreen, solder mask etc to duplicate the turret board and my amps are better and quieter than ever, and quicker and easier to build. I had thought of putting the sheets of Tufnol in an oven to dry them out, but now I have proper boards I just can't be ar*ed. If you are going to use board, use glass fibre based board.

Nigel

[bnwitt]

Mount your boards with stand offs and O rings for vibration absorbtion. Also, 1/8" G10 FR4 (the FR stands for flame resistant) is very rigid and not prone to vibration like the 1/16" thickness. Not all fiberglass board is good for electrical isolation either. The 1/8" thick G10 FR4 is the best for circuit cards.
Barry

[markd]

RadioSpares still makes the turrets you see on old Marshalls. That's my guess where they are getting the ones for the handwired series. Too bad they don't still have the perfboard. Go to their online catalog here:

http://rswww.com

and put 433589 in the search window. RadioSpares is a sister company with Allied here in the states. I got some of these turrets a few years ago through Allied. At that time the Allied part# was 090S0102. I had a hard time with the regular order person over the phone, but the supervisor was able to order from RS for me. There may be a minimum order required, but with the current exchange rate these turrets are almost $20 per 100.
hth, markd

[lastwinj]

Germ, you mention paper phenolic, I have a large piece of paper phenolic I was going to use for circuit cards until I read about "tweed disease" where the phenolic picks up moisture and changes to be conductive and/or capacitive. Have you or anyone else heard of this? I decided not to use the phenolic out of fear of future problems with it.

all is not created equal. the cheapy stuff does do that. but a garolite XX is a paper phemolic, IIRC, and there are no problems with it.

germ

[lastwinj]

if u use turrets, use double level turrets. not much money, and you wont have to derate a resistor as much.

nylon standoffs would work for your aplpication, but they are just cheesy, IMO. mesa likes to use these, in some of the amps. .22 caliber plus comes to mind. pain to work on too. used computer press in standoffs. joy.

germ

[lastwinj]

RadioSpares still makes the turrets you see on old Marshalls. That's my guess where they are getting the ones for the handwired series. Too bad they don't still have the perfboard. Go to their online catalog here:

probably sourcing them from china. radiospares would be too expensive, is my guess.

germ

[Coco]

I know you wanted a supply of these but just in case you, or anyone else is interested and want a few boards, we have some extra 18W size. Take a look. email for info

http://www.18watt.com/modules.php?set_a ... _photo.php

[Coco]

1/8" thick Garolite, "Red Swirl" perf board with authentically reproduced Marshall hole grid pattern. This is the same material we use in our Trinity amps and is of very high quality.

What size are those, btw?[/quote]
Our supplier mistakenly cut off one row of holes so there are only 6 rows of holes, not 7. Grid pattern is: 6 X 27 holes that fit standard turrets
Size: 10" X 2.5"
------------------
These are surplus boards.

http://18watt.com/modules.php?name=Foru ... pic&t=3647

[Coco]

BTW, price is $15 per board, including shipping in North America.

[Coco]

BTW, price is $15 per board, including shipping in North America.

All the boards are sold. Thanks.

[Coco]

Others on this post have pointed to various manufacturers of Garolite type material.

[Coco]

I purchased this from a distributer up here in Toronto, Canada so I took this opportunity to do some research for the 18 Watt community. If you're looking for the red swirl board you saw on my posting, order GPO-3. It's a common material because of it's use in the power distribution industry and McMaster-Carr sells it in strips. http://www.mcmaster.com

Their Part Number is: 3345K11. Electrical Grade Fiberglass Strip (GP03) 1/8" Thick, 3" Width X 36" Length, Red .

I hope this helps everyone out.

Here are the specs for Electrical-Grade Fiberglass (GPO3)

Good electrical insulation properties combined with high strength and flame resistance make this material an excellent choice for electrical applications. It's a glass fiber-reinforced polyester. Meets UL 94V0 for flammability.

• Color: Opaque red
• Max. Temp.: 248° F, not rated for low-end temperature use
• Softening Temp.: Not rated
• Tensile Strength: Excellent
• Impact Strength: Excellent
• Good electrical insulator
• Use indoors
• Machine with carbide tooling



Meet the following standard: UL 94V0 for flammability.
Tensile Strength: 10,000 psi per ASTM D638
Impact Strength: 8.2 ft.-lbs./in. per ASTM D256
Dielectric Strength: 400 V/mil per ASTM D149
Tracking Index: 500 volts per ASTM D3638
Hardness: Barcol 50 per ASTM D2583
Coefficient of Thermal Expansion: 1.11×10-5 in./in./°F per ASTM D696
Weather Resistance: Use indoors. Not intended for long-term outdoor exposure.
Processing: Machinability: Can be easily machined with carbide or diamond-tipped tooling. Holes are easily
created using conventional drill bits and milling bits. A dust mask and gloves
should be worn when working on this material.
Molding: Not recommended.
Welding: Not recommended.
Thermoforming: Not recommended.
Scratch Resistance: Fair.
Chemical Resistance: Use with mild detergents. Do not use with strong acids.