Update as of 3/2/06
I opened some tubes and spent half of last night matching devices. Then hit it again this afternoon after I got the kid down for her nap. I've got...I think...enough devices matched to square away the European order. I'll have to sit down and look at the totals to see where things stand. If I don't have enough, I'll pull a few more tubes and match them.
--which brings me to another point--
There still seems to be a lot of misunderstanding about the matching process. For reasons known only to the electronics gods, I'm getting another wave of e-mail requesting devices that haven't been ravaged by heathen hands.
Sigh...
For some reason, people seem to grok the idea of reading a single device, but their minds cloud when they try to conceive of matching a group. Let me try this hypothetical example:
--You have ten devices
--You test all ten devices, not three, not one, not eight, but all ten. At the end of the testing, you have how many? Ten matched devices! With how many left over? None!
--The devices rank as follows:
Voltage A--1 device
Voltage B--2 devices
Voltage C--5 devices
Voltage D--2 devices
--You receive orders as follows:
Ethel--1 device
Mabel--3 devices
Florence--2 devices
Evelyn--1 device
--So where do you go from here? Well, Mabel wants 3 matched devices and the only group that will support her order is C. So you pull Mabel's devices from C, leaving the following inventory:
A--1
B--2
C--2
D--2
--Florence wanted 2 devices. You can pull her devices from B, C, or D. You decide on D. Your inventory now looks like this:
A--1
B--2
C--2
---Ethel and Evelyn both wanted 1 device each. Again, you have options, but you decide to send them each a device from the C group, leaving your inventory thus:
A--1
B--2
Okay, so what's the point of this little exercise? To demonstrate that there are no, repeat NO ravaged tubes of parts left behind. All the parts were matched. All the parts were assigned bins. All the parts will sit there until they are matched with happy owners.
In my case, which--granted--is a little more complicated than the above, I match five or ten entire tubes at a time, leaving the rest of the stock untouched.
For reasons that are unclear to me, people persist in believing that there are tubes of parts that have been raped and pillaged. They don't want those tubes. They want tubes that are "untouched" or "that haven't had all the good ones taken out" or "virgin."
(Brief digression: I never understood what all the hullabaloo about virgins was about. They're never any good because they're scared and inexperienced. Give me a girl who is relaxed, confident, and knows what she's doing and I'm a happy boy. End of digression.)
Please, please, please...try very hard to grasp this...there aren't any 'picked-over' tubes!
Jeez, you ought to see some of these e-mails I get. Semi-hysterical, accusing, suspicious, worried...before they even get around to ordering. They want to know if there are untouched tubes left before they'll even place an order.
Grumble, grumble, grumble...
Okay, on to the next thing. I've got a guy who's unhappy because I didn't get his order packaged and sent the way he wanted. No matter how you slice it, this one was my fault--not the "locked box" lady, not the bank...mine. The parts went out, just not the way he requested. The thing you guys have to understand is that I've got well over three hundred e-mails in my mailbox right now. Everybody and his brother wants parts, which is good. But...then I get an e-mail saying that he wants to change this or that or the other. Then another e-mail reverting to the original plan, or worse yet, something entirely different. Given the sheer quantity of changing--and frequently contradictory--information coming at me, it's a bloomin' miracle that I'm able to keep track of anything.
As far as I know, there's only the one guy who didn't get things sent the way he wanted, but if you wanted your parts sent by carrier pigeon and I sent them by Wells Fargo, please accept my apologies. Just try to understand, okay?
Next time...if there is a next time, which I currently doubt...I'm going to allow for one and only one shipping option. Take it or leave it. This is driving me crazy.
Grey, you sound a little cranky, fella.
Do I? Yeah, I guess so.
In addition to the usual things, I now have two, count 'em, two separate plumbing problems, which aren't the kind of problems you can put on a shelf and ignore.
Lemme get some sleep. Maybe I'll be less ornery tomorrow.
Grey
I opened some tubes and spent half of last night matching devices. Then hit it again this afternoon after I got the kid down for her nap. I've got...I think...enough devices matched to square away the European order. I'll have to sit down and look at the totals to see where things stand. If I don't have enough, I'll pull a few more tubes and match them.
--which brings me to another point--
There still seems to be a lot of misunderstanding about the matching process. For reasons known only to the electronics gods, I'm getting another wave of e-mail requesting devices that haven't been ravaged by heathen hands.
Sigh...
For some reason, people seem to grok the idea of reading a single device, but their minds cloud when they try to conceive of matching a group. Let me try this hypothetical example:
--You have ten devices
--You test all ten devices, not three, not one, not eight, but all ten. At the end of the testing, you have how many? Ten matched devices! With how many left over? None!
--The devices rank as follows:
Voltage A--1 device
Voltage B--2 devices
Voltage C--5 devices
Voltage D--2 devices
--You receive orders as follows:
Ethel--1 device
Mabel--3 devices
Florence--2 devices
Evelyn--1 device
--So where do you go from here? Well, Mabel wants 3 matched devices and the only group that will support her order is C. So you pull Mabel's devices from C, leaving the following inventory:
A--1
B--2
C--2
D--2
--Florence wanted 2 devices. You can pull her devices from B, C, or D. You decide on D. Your inventory now looks like this:
A--1
B--2
C--2
---Ethel and Evelyn both wanted 1 device each. Again, you have options, but you decide to send them each a device from the C group, leaving your inventory thus:
A--1
B--2
Okay, so what's the point of this little exercise? To demonstrate that there are no, repeat NO ravaged tubes of parts left behind. All the parts were matched. All the parts were assigned bins. All the parts will sit there until they are matched with happy owners.
In my case, which--granted--is a little more complicated than the above, I match five or ten entire tubes at a time, leaving the rest of the stock untouched.
For reasons that are unclear to me, people persist in believing that there are tubes of parts that have been raped and pillaged. They don't want those tubes. They want tubes that are "untouched" or "that haven't had all the good ones taken out" or "virgin."
(Brief digression: I never understood what all the hullabaloo about virgins was about. They're never any good because they're scared and inexperienced. Give me a girl who is relaxed, confident, and knows what she's doing and I'm a happy boy. End of digression.)
Please, please, please...try very hard to grasp this...there aren't any 'picked-over' tubes!
Jeez, you ought to see some of these e-mails I get. Semi-hysterical, accusing, suspicious, worried...before they even get around to ordering. They want to know if there are untouched tubes left before they'll even place an order.
Grumble, grumble, grumble...
Okay, on to the next thing. I've got a guy who's unhappy because I didn't get his order packaged and sent the way he wanted. No matter how you slice it, this one was my fault--not the "locked box" lady, not the bank...mine. The parts went out, just not the way he requested. The thing you guys have to understand is that I've got well over three hundred e-mails in my mailbox right now. Everybody and his brother wants parts, which is good. But...then I get an e-mail saying that he wants to change this or that or the other. Then another e-mail reverting to the original plan, or worse yet, something entirely different. Given the sheer quantity of changing--and frequently contradictory--information coming at me, it's a bloomin' miracle that I'm able to keep track of anything.
As far as I know, there's only the one guy who didn't get things sent the way he wanted, but if you wanted your parts sent by carrier pigeon and I sent them by Wells Fargo, please accept my apologies. Just try to understand, okay?
Next time...if there is a next time, which I currently doubt...I'm going to allow for one and only one shipping option. Take it or leave it. This is driving me crazy.
Grey, you sound a little cranky, fella.
Do I? Yeah, I guess so.
In addition to the usual things, I now have two, count 'em, two separate plumbing problems, which aren't the kind of problems you can put on a shelf and ignore.
Lemme get some sleep. Maybe I'll be less ornery tomorrow.
Grey
Guys,
I've been thinking about this and in an attempt to rein in some of the insanity, I'm going to go to one domestic shipping method. Effective immediately, all parts will go out as standard mail. I will attempt to honor any prior requests for special this-and-that, but it's getting way too hard to keep up with all the nonsense.
This specifically means:
no insurance
no Registered
no static bags (despite the nervous qualms of a few, not one of these things has died that I've heard of)
no padded bags
no boxes
no Priority Mail
no Overnight
no nuthin'
What you get is a standard envelope with a light cardboard insert, sent First Class. Literally thousands of devices have been sucessfully delivered this way. It's cheap enough that the guys ordering two devices aren't paying twenty times the device cost in shipping. And it reduces the absurd number of permutations I've had to deal with when shipping these things out.
Foreign orders go out in cardboard boxes, but then we're dealing with hundreds of devices and need more room anyway.
Sorry, I tried to accomodate on the shipping thing, but when one guy wants a padded bag, insurance, but not registered, another guy wants an envelope, registered, but no insurance, and a third wants Priority and Registered, it gets difficult trying to keep it all straight.
Grey
I've been thinking about this and in an attempt to rein in some of the insanity, I'm going to go to one domestic shipping method. Effective immediately, all parts will go out as standard mail. I will attempt to honor any prior requests for special this-and-that, but it's getting way too hard to keep up with all the nonsense.
This specifically means:
no insurance
no Registered
no static bags (despite the nervous qualms of a few, not one of these things has died that I've heard of)
no padded bags
no boxes
no Priority Mail
no Overnight
no nuthin'
What you get is a standard envelope with a light cardboard insert, sent First Class. Literally thousands of devices have been sucessfully delivered this way. It's cheap enough that the guys ordering two devices aren't paying twenty times the device cost in shipping. And it reduces the absurd number of permutations I've had to deal with when shipping these things out.
Foreign orders go out in cardboard boxes, but then we're dealing with hundreds of devices and need more room anyway.
Sorry, I tried to accomodate on the shipping thing, but when one guy wants a padded bag, insurance, but not registered, another guy wants an envelope, registered, but no insurance, and a third wants Priority and Registered, it gets difficult trying to keep it all straight.
Grey
Grey,
I received the 25 Matched JFet's on a cardboard, and all is fine!! 🙂
{If I get some time, my GF uses a lot ; I'll do some tests with them...}
Thanks so much for doing the Matching and the GroupBy ; you are our Santa
on March 06 !!
If you get some time ; could you please tell us if there are some JFet's left,
I would probably send an other letter to Santa {Grey} for a second delivery...
We wouldn't want you to store a lot of unsold parts...
So how many unsold JFet's ?
PS: You always tell us good stories ; please keep going!
I loved the "been raped " passage... {speaking of JFet's tubes, of course!}
Best regards.
Alain.
I received the 25 Matched JFet's on a cardboard, and all is fine!! 🙂
{If I get some time, my GF uses a lot ; I'll do some tests with them...}
Thanks so much for doing the Matching and the GroupBy ; you are our Santa
on March 06 !!
If you get some time ; could you please tell us if there are some JFet's left,
I would probably send an other letter to Santa {Grey} for a second delivery...
We wouldn't want you to store a lot of unsold parts...
So how many unsold JFet's ?
PS: You always tell us good stories ; please keep going!
I loved the "been raped " passage... {speaking of JFet's tubes, of course!}
Best regards.
Alain.
I've still got parts, both matched and unmatched.
I even have parts that are unmolested, unraped, untouched, and virginal, for those who need that to fuel their fantasies.
Grey
I even have parts that are unmolested, unraped, untouched, and virginal, for those who need that to fuel their fantasies.
Grey
Just in case it wasnt clear in my previous post: I can not handle more orders at this point. The extras I ordered have been swallowed by orders, so I will have to ask Grey for a little raise in the quantity, and I hate to do that right now
Figure out why, yourself. Obviously I am too much of a nice guy, I cant turn anyone down.
I am absolutely certain that these devices has not been misused for obscure purposes, except for people eating them for breakfast😉 I will do whatever I can to fill all orders received so far. There is a few people I didnt get back to yet, reason being that I dont know if I can fill their order. You will get your answer though.
Steen🙂 (in pretty good mood😎 )
Figure out why, yourself. Obviously I am too much of a nice guy, I cant turn anyone down.I am absolutely certain that these devices has not been misused for obscure purposes, except for people eating them for breakfast😉 I will do whatever I can to fill all orders received so far. There is a few people I didnt get back to yet, reason being that I dont know if I can fill their order. You will get your answer though.
Steen🙂 (in pretty good mood😎 )
I warned you guys ages ago that I'd be a monster to put up with at times. Now is one of those times.
What...you didn't believe me?
Steen's a nice guy. I'm obviously in my Mr. Hyde phase at the moment.
Steen,
I've got parts. If you want more, all you have to do is ask. I may growl, but I don't bite.
At least not very often.
(And I've had my rabies vaccination, so all you have to worry about is blood loss, scarring, and the possible loss of a limb or two.)
I've got the baby down for a nap, which means that she's tearing up the house instead of sleeping. Being both fearless and foolish, I'm heading down to the Dungeon to freeze my (mumble) off and match more parts. The Australian order needs a few more to make good on a last minute addition or two (I am told that the Australian order is now Absolutely, Positively, Without Doubt CLOSED), not to mention the European stuff.
If anyone wants to start another Australian buy, let me know. Stones said that he was only going to go one round. Given the number of DIY members from down there, I'm really surprised that they're letting the Europeans kick their rumps.
Grey
What...you didn't believe me?
Steen's a nice guy. I'm obviously in my Mr. Hyde phase at the moment.
Steen,
I've got parts. If you want more, all you have to do is ask. I may growl, but I don't bite.
At least not very often.
(And I've had my rabies vaccination, so all you have to worry about is blood loss, scarring, and the possible loss of a limb or two.)
I've got the baby down for a nap, which means that she's tearing up the house instead of sleeping. Being both fearless and foolish, I'm heading down to the Dungeon to freeze my (mumble) off and match more parts. The Australian order needs a few more to make good on a last minute addition or two (I am told that the Australian order is now Absolutely, Positively, Without Doubt CLOSED), not to mention the European stuff.
If anyone wants to start another Australian buy, let me know. Stones said that he was only going to go one round. Given the number of DIY members from down there, I'm really surprised that they're letting the Europeans kick their rumps.
Grey
I did🙂 Hope you had my email. I am not the only nice guy around here, all the guys sending me emails on this matter are all very nice and patient guys, too😉 No problems so far. Take your time to handle this matter. I myself, am just glad to have the oppertunity to build one of NP's J-fet poweramps, and I am sure the guys ordering the devices feels the same way. I can tell you that the J-fet poweramp sounds really great🙂 I was lucky enough to finish one of those at this point, and I am really happy with the sound of it😎
Steen🙂
You know, it's a funny thing. For all the fact that I'm hip-deep in these things--and even had a pair to begin work with back late last summer--I've yet to hear a single note through them. Everything has been test signals on the bench. All work and no play.
It's a case of the cobbler who had no shoes, I'm afraid.
One day I hope to hear music through a power JFET amp.
Grey
It's a case of the cobbler who had no shoes, I'm afraid.
One day I hope to hear music through a power JFET amp.
Grey
I understand your point very well indeed. Well, all I can say is that you have something to look forward to🙂 Thats not a bad thing, I guess. Since I put the ZenV8/9 I made, in the main system, I never wanted to replace it😉 Well Grey, if I know you half as good, as I think I do from this forum, you will have your shot at these amps?? Good luck and happy building, when you find the time for it🙂
Steen😎
Steen😎
Just wanted to say that I got my 50 parts from Mr. Rollins, no muss, no fuss, no bother. They take up a surprisingly small amount of space - I'll have to use a few before I misplace them.... I was thinking of soldering the devices to copper heat spreaders - I'll let folks know eventually how that effort works out.
I have some 1/8" copper on hand and have considered the solder route, but...oh, Gussy, the trouble you'll have if you ever blow one and have to replace it.
On the other hand, heat transfer in a metal (device)/metal (solder)/metal (heatsink) contact is fantastic.
Grey
P.S.: Man...talk about cathartic. I went out with wife and child this evening. I and the baby went stomping up and down isles at the store growling and snarling and being "monsters." I figured that if I was being a monster here I might as well go whole hog (foreign folks: that's an idiom that means to go the full distance). Boy, that was fun. We got some strange looks, but there was this one little old lady about 10,000 years old and more wrinkles than a raisin who thought it was hilarious to see this grown man and a three year-old being dinosaurs. We went over and gave her a good growling. She thought it was great.
Ha! Believe it or not, there are times when it's good to be a monster.
On the other hand, heat transfer in a metal (device)/metal (solder)/metal (heatsink) contact is fantastic.
Grey
P.S.: Man...talk about cathartic. I went out with wife and child this evening. I and the baby went stomping up and down isles at the store growling and snarling and being "monsters." I figured that if I was being a monster here I might as well go whole hog (foreign folks: that's an idiom that means to go the full distance). Boy, that was fun. We got some strange looks, but there was this one little old lady about 10,000 years old and more wrinkles than a raisin who thought it was hilarious to see this grown man and a three year-old being dinosaurs. We went over and gave her a good growling. She thought it was great.
Ha! Believe it or not, there are times when it's good to be a monster.
I don't think I'll have a big problem replacing a frappped JFET - it'll unscrew and unsolder just like any other component. If I think ahead of time and make several JFET/heat spreader assemblies, things will be even simpler. I'm thinking of using indium solder for the mount down, as I am a techno-nerd and have some of the stuff around.
Yeah, there used to be Indium tribes around here before the settlers arrived.
Ahem...
Okay, so I get loopy when I'm short on sleep. You guys already knew that, right?
Grey
Ahem...
Okay, so I get loopy when I'm short on sleep. You guys already knew that, right?
Grey
Wouldnt the heat be of concern when soldering the whole transistor case? The Fet will get really hot.
It would make a really neat solution, though.
Steen🙂
steenoe said:
You'd be surprised how much heat small surface mout parts can handle for about 5 to 10 seconds. These are much smaller than D2Pak packages and they take at least 5 seconds of 750 degrees F to get good flow over the whole pad (using a good bit of flux too). The best solution would be to design a pcb with heat pads for the part and just solder it to that.
I'd recommend bringing a larger metal heatsink up to a decent temperature (say at least 250 degrees F) before trying to solder the part to it. If you don't, a good heat sink will just pull the heat away from your iron and you won't get the solder to flow properly.
P.S. Thanks for the JFETs Grey.
Strangelove -
The indium-tin eutectic you referenced would do the trick. The only problem I can see it that it's not in a convenient physical form for soldering. I picked up my indium solder on Ebay a long time ago, mostly because it has the unusual property of being able to solder glass, quartz, silicon, and other usually unsolderable materials. As far as I know, rosin-based flux would work with this stuff for copper and tinned surfaces. As the melting temperature is much lower than a tin-lead eutectic, one is much less likely to damage the part soldered. I plan to tin the device and spreader separately, heat up the spreader, then pop the device in place and let it cool. With a hotplate, you could do a batch of devices at once. More information on indium alloys and their properties can be found at the Indium Corporation of America web site (Google is your friend).
As far as the actual form of the spreader, I'm thinking of a rectangular piece with two mounting holes, the same size as a chip amp IC, in order to accomodate silpads mde for chip amps. In reality, since the JFET will be used with a cascode, dissipation is likely to be only 5-10W, and a TO-220 or TO-3P sized spreader would likely work just dandy. I'll know more as my design proceeds - slowly, at best, as I have a load of other items on my plate.
The indium-tin eutectic you referenced would do the trick. The only problem I can see it that it's not in a convenient physical form for soldering. I picked up my indium solder on Ebay a long time ago, mostly because it has the unusual property of being able to solder glass, quartz, silicon, and other usually unsolderable materials. As far as I know, rosin-based flux would work with this stuff for copper and tinned surfaces. As the melting temperature is much lower than a tin-lead eutectic, one is much less likely to damage the part soldered. I plan to tin the device and spreader separately, heat up the spreader, then pop the device in place and let it cool. With a hotplate, you could do a batch of devices at once. More information on indium alloys and their properties can be found at the Indium Corporation of America web site (Google is your friend).
As far as the actual form of the spreader, I'm thinking of a rectangular piece with two mounting holes, the same size as a chip amp IC, in order to accomodate silpads mde for chip amps. In reality, since the JFET will be used with a cascode, dissipation is likely to be only 5-10W, and a TO-220 or TO-3P sized spreader would likely work just dandy. I'll know more as my design proceeds - slowly, at best, as I have a load of other items on my plate.
Please understand that I share Steeno's reservation. I said as much in another thread. Most of these things are indeed intended to solder to pads on the circuit board. If you start experimenting with comparatively heavy pieces of metal the assembly will stay hotter, longer and it could damage the device.
If you're willing to risk a few devices to experiment, feel free to do so. I'm still using the mechanical method for the time being. I still have one idea left that I want to look into, but none of the other things I wanted to try has worked out as well as the screws/retaining bar method.
Grey
If you're willing to risk a few devices to experiment, feel free to do so. I'm still using the mechanical method for the time being. I still have one idea left that I want to look into, but none of the other things I wanted to try has worked out as well as the screws/retaining bar method.
Grey
I'm using indium solder for attachment to the heat spreader to limit thermal damage. The max temperature will be below the max storage temperature for the device. I don't like using pressure bar type setups, as it can be difficult to assure even pressure across the device, especially with multiple devices, though some bellville washers in the stackup might help...
As a point of reference, I'm using Indalloy 1E, a eutectic with composition 52/48 In-Sn. The melting point is only 118C, high enough so that the device will stay soldered with proper heatsink design, but low enough to stay comfortably below both the max operating and storage temperature of 150C.
As a point of reference, I'm using Indalloy 1E, a eutectic with composition 52/48 In-Sn. The melting point is only 118C, high enough so that the device will stay soldered with proper heatsink design, but low enough to stay comfortably below both the max operating and storage temperature of 150C.
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