Hi folks, I'm at the point where I'm laying out the B+ rectifier board for my 8877 project, and it occurs to me I don't know much about component spacing for high-voltage (2800 VRMS, 3900VDC typical)
It appears as though no one answered you, at least not on the reflector. I'd question the sanity of homebrewing rectifier boards when K2AW's modules are so cheap, are well insulated, and work great.
Jim-- Take a look at the boards on Paul's site. Think it might save you a lot of time. http://wd7s.home.att.net/triode_control.htm Good Luck--John W0UN John W. Brosnahan shr@ricc.net -- FAQ on WWW: h
Steve, John, and others that replied off the reflector: Thanks for the replies. I agree that it's much easier to buy pre-built modules, certainly cheaper when you consider the cost of having prototyp
Hi Jim, I surely wouldn't bother with the setup costs of prototyping PC boards for an array of diodes...the off-the-shelf prototype boards in all the electronics hobby stores will do the job just fin
Hi Jim, K2AW Silicon Alley telephone (516) 334-7024. "Same day shipping." 8kV, 250A surge modules = $10.00/each. They're not large, I cannot imagine a "board" version being any smaller. 73, Jim! Stev
Hi Paul, There's no 6A equivalent part to the JTX1N5554. Problem is, JAN parts must be hermetically sealed by spec, and to make a 6A glass or ceramic dual-plug, metalurgically-bonded part is nearly i
// We sell 1n5408, 1000piv, 200A peak, 3A avg. diodes for 17-cents each or $14.40 per hundred. . . When mounted on perfboard, the junctions run cooler than epoxy-potted diode-blocks because cooling
A perfboard version is not smaller but it runs at lower junction temps. A board version of 8kV/3A costs $1.36 plus the cost of the perfboard. - R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measu
Add a heatsink, and the perfboard version takes up less volume. - R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures. end -- FAQ on WWW: http://www.contesting.com/FAQ/amps Submissions: amps@c
So what is the avg current rating of the same 1n5408/3A diodes when they are potted by K2AW? I have used potted diodes and - with the requisite heatsink - they were larger than the low-tech perfboar
Hi Rich, The K2AW modules are rated 1.0A at 55 degrees C, derating to zero at 150 degrees C. Thus, a bridge made of four such modules would have a 2.0A/55 deg C rating, attached to any surface having
Since this beastie will only see an ampere on the rare and unintended peak, I suspect that either diode strings or modules will last a long time, unless It Happens. There's a 50-ohm, 100-watt resisto
/ There is no such statement on the tech spec sheets. If a seal is leaky, the tube is history. cheers, Jim - R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures. end -- FAQ on WWW: http://www.
\ I mount the rectifiers G-10 perfboard supported by an aluminum bracket in the inlet air-stream. It works, takes less space and 11kV @ 3A costs around $5 for a FWD. \ Yea, verily. I used to have an
And Rich answered: Ah. Then the tales of heating the tubes for a period after extended storage are just that. I have no reason to believe any seal is leaky, but I had heard that the potential for a s
// On the surface it sounds like a helpful tip. With some multi-hundreds of kWs, 22kV electron-tubes that have been in storage, it may be a good idea to run the ion-pump for a while before blastoff.
Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK)
Date: Tue, 20 Nov 2001 15:39:05 +0000
No, they're not just tales. There are two ways gas can get into a vacuum tube. One is through a faulty seal, as Rich said. But even if a tube has perfect seals, the inside surfaces of the tube can ve
Ian, Ok, that makes sense. I suppose an inverted way of looking at it is that if the tube -didn't- emit any gas internally, there would be no need for a getter. One of the reasons I asked was based o