I'm getting ready for a massive purchase of IRFP 244's for Aleph 1.2, Aleph 2, and a few Aleph x's. Between me and a friend, we're buying 150 so far, but the more the merrier for matching. The plan is to heat to 150 deg F in distilled water, and record Vgs at .5A and .75A. From this, we'll compute transconductance (dv/di) and divide into 4 to 6 groups to be then matched for Vgs.
This should make for very close matches. And with these quantities, They will cost less than $2.00 US each.
If anyone's interested, post here.
I'll also send everyone consecutive parts so if you want to rematch, they could be changed from say 4 groups of 6 to 6 groups of 4 and not have oddballs.
Or if you want say groups of 2 or 3 (for samller Alephs) I may give a price break because I'm looking for groups of 12 and will likely have a lot of two-zys and three-zys left over.
This should make for very close matches. And with these quantities, They will cost less than $2.00 US each.
If anyone's interested, post here.
I'll also send everyone consecutive parts so if you want to rematch, they could be changed from say 4 groups of 6 to 6 groups of 4 and not have oddballs.
Or if you want say groups of 2 or 3 (for samller Alephs) I may give a price break because I'm looking for groups of 12 and will likely have a lot of two-zys and three-zys left over.
Wow. That's around 300 fets. With that many, we should have pretty tight tolerences with not much waste.
jrsun, are you making one channel A1.2? or a pair. 24 fets or 48?
Some of you may want to consider... for A 1.2, get 4 sets of 13 for a pair of monoblocks. If you spark out 1 fet by some strange act, you'll have a spair instead of trashing the whole set of 12. $8.00 would be cheap insurance. Static happens.
AR2, please clairify your quantity.
I'll work up details and nail everyone down early next week.
jrsun, are you making one channel A1.2? or a pair. 24 fets or 48?
Some of you may want to consider... for A 1.2, get 4 sets of 13 for a pair of monoblocks. If you spark out 1 fet by some strange act, you'll have a spair instead of trashing the whole set of 12. $8.00 would be cheap insurance. Static happens.
AR2, please clairify your quantity.
I'll work up details and nail everyone down early next week.
I'll make a list of everyone and Email this week. Manufacture will be International Rectifier. I quoted a price of less than $2 each, and I shouldn't exceede that by much, but if this order gets big, I need to factor in sales tax, shipping to me, and a % waste for fets that fall outside spec. Noone has asked for 4 sets of 2 where these oddballs could be used.
I'll work out the details and let you know. And if I do factor in 5% waste, I'll send an extra fet with every 20 to use as mounting template or for speed control for fan or something. I'm not trying to make a buck, just don't want to loose my shirt in the deal. I think everyon will win by getting closer matches that if we all bought 25 fets individually and tried to get 4 sets of 6.
I'll work out the details and let you know. And if I do factor in 5% waste, I'll send an extra fet with every 20 to use as mounting template or for speed control for fan or something. I'm not trying to make a buck, just don't want to loose my shirt in the deal. I think everyon will win by getting closer matches that if we all bought 25 fets individually and tried to get 4 sets of 6.
I'm back. I had to fire my top 2 employees, and then take up the slack for the last few days.
To all of you comrads outside the USA, I'll have to visit the post office to see how much it will cost to ship to you and work out a payment method. I need to ask my bank about out of country checks. I trust that they'll be good, but I need to see about fees and such. I'll Email everyone that has posted early next week. (I hope)
I'm stoked. We should all be able to all have fets matched to .02 Vgs.
To all of you comrads outside the USA, I'll have to visit the post office to see how much it will cost to ship to you and work out a payment method. I need to ask my bank about out of country checks. I trust that they'll be good, but I need to see about fees and such. I'll Email everyone that has posted early next week. (I hope)
I'm stoked. We should all be able to all have fets matched to .02 Vgs.
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