I wouldn't be afraid of using it at 0.5 to 1 to 2 amperes for longer durations (i.e. audio cycles). I mean, compare the heater dissipation (=emission capacity) to any other tube. 6V6 is good for what 200mA from a mere 3W heater, this thing uses what 20-25W, that's 8 times more or 1.6A Ik, not bad I'd say.. 
Besides, 100-200V over 1/8" distance or so (i.e. circa 63kV/m E-field) is surely enough to sweep out any old electrons hanging around in the space charge in under a microsecond. (IANAP (physicist), but there isn't any trouble with velocity modulation below 200MHz in these types, AFAIK.)
Tim
Besides, 100-200V over 1/8" distance or so (i.e. circa 63kV/m E-field) is surely enough to sweep out any old electrons hanging around in the space charge in under a microsecond. (IANAP (physicist), but there isn't any trouble with velocity modulation below 200MHz in these types, AFAIK.)
Tim
PL509/519/40KG6
As I said, The actual electrons have no memory, I have had this as an interlectual discussion for many years and no physicist has yet put forward a case for this. I digress, but that is why trying to make chip memory transistors with geometries of a few molecules, the molecules move about randomly and the juctions migrate and identifying the logic state becomes unreliable.
I still see that the thumb nail hand drawn circuit uses screen volts well above the data sheets recomended value of 160 volt. in practice 180 is the absolute maximum for realiabity. At 320 volt you will need over a hundred volts negative on the grid to bias it and secondary emission becomes unmanagable. Rather go for high plate volts such as 5 to 600 volts. This tube was in its original design intended for TV and had to handle up to 8KV flyback and as the previous message stated that a peak current of over an Amp for very short duty cycle.
The reson I used this tube for so long is that of all mass produced tubes for the entertainment not professional market, it had the largest cathode surface area some 40% more that the usual KT88 etc., And rightly said 250MA continuous for PSU applications whilst staying within the 35 watt plate disipation (this rating was for horizontal scan duty) is no problem for 5 kilohours.
The Russian EL519 with its larger diameter class is good for 45 watts continous for the same bulb temperature as say the EL34 at 25 watts.
As I said, The actual electrons have no memory, I have had this as an interlectual discussion for many years and no physicist has yet put forward a case for this. I digress, but that is why trying to make chip memory transistors with geometries of a few molecules, the molecules move about randomly and the juctions migrate and identifying the logic state becomes unreliable.
I still see that the thumb nail hand drawn circuit uses screen volts well above the data sheets recomended value of 160 volt. in practice 180 is the absolute maximum for realiabity. At 320 volt you will need over a hundred volts negative on the grid to bias it and secondary emission becomes unmanagable. Rather go for high plate volts such as 5 to 600 volts. This tube was in its original design intended for TV and had to handle up to 8KV flyback and as the previous message stated that a peak current of over an Amp for very short duty cycle.
The reson I used this tube for so long is that of all mass produced tubes for the entertainment not professional market, it had the largest cathode surface area some 40% more that the usual KT88 etc., And rightly said 250MA continuous for PSU applications whilst staying within the 35 watt plate disipation (this rating was for horizontal scan duty) is no problem for 5 kilohours.
The Russian EL519 with its larger diameter class is good for 45 watts continous for the same bulb temperature as say the EL34 at 25 watts.
Where do you get 20-25W from? 40V at 300mA sounds like 12W to me. I looked up the 1972 Philips data sheet and it states 500mA maximum continuous current and 1.5A peak current. If you attempt to drag 1.5A continuously, the valve will saturate because you will exhaust the space charge - it's no longer a question of the applied electric field but the cathode's emissive capability.
Oh, it's only 12W? I thought it was the biggest sweep of them all (more or less), bigger than say 6KD6 (which runs 18W heat)?
If that's the case, then just derate my post slightly... still good for some chunky performance.
Just imagine what you'd get if you brought one out to the extremes of its design limits - 3kV B+ and 1-2A peak (sure, go ahead and saturate the thing) - that's an instantaneous load peak of 6 kilowatts!
Oh, and speaking of saturation, cathodes have a *long* way to go before that happens. The rated specs are for reliable life; peak specs for capacity, and absolute maximum emission somewhere above that. IIRC, unipotential oxide cathodes are good for 300mA/W? Not going to last too long of course (cathode stripping, anyone?).
Tim
If that's the case, then just derate my post slightly... still good for some chunky performance.
Just imagine what you'd get if you brought one out to the extremes of its design limits - 3kV B+ and 1-2A peak (sure, go ahead and saturate the thing) - that's an instantaneous load peak of 6 kilowatts!
Oh, and speaking of saturation, cathodes have a *long* way to go before that happens. The rated specs are for reliable life; peak specs for capacity, and absolute maximum emission somewhere above that. IIRC, unipotential oxide cathodes are good for 300mA/W? Not going to last too long of course (cathode stripping, anyone?).
Tim
40KG6 vs 6KD6
I think you will find that the 300 MA version of the 6KD6 is called the 40KD6 and has the same heater requirements as the 40 KG6.
aka the PL509. All these TV tubes were both in the USA and Europe developed for Colour TV. the Japanese merely made similar as licensee. Matsushita made them as a Philips offshoot. So did NEC Toshiba etc.
So all were variations on a theme.
I think you will find that the 300 MA version of the 6KD6 is called the 40KD6 and has the same heater requirements as the 40 KG6.
aka the PL509. All these TV tubes were both in the USA and Europe developed for Colour TV. the Japanese merely made similar as licensee. Matsushita made them as a Philips offshoot. So did NEC Toshiba etc.
So all were variations on a theme.
planet10 said:
OT
Indistinguishable particles in a multielectron system, otherwise no Fermi and no exchange energy. You might be thinking of the case where spins correlate if two electrons are thrown out in a decay (similar to EPR paradox). It's not a matter of memory, it's quantum spookiness a.k.a. entanglement.
Hi edl!
I know that schematic. DDL told me, that he he would radically modify that circuit. He would throw out the first ECC808 "section".
BTW, i'm going to have 2 output transformers, with Raa=2.5kOhm, and the secondary is 4ohm. They were made for tha APX100.
the apx100's power would be good for me, becouse I have 8ohm speakers, so I could have about 50W output power.
edl, what do you think of APX100? Is it worth building a modified APX100?
De miert nem magyarul tarsalgunk?
I know that schematic. DDL told me, that he he would radically modify that circuit. He would throw out the first ECC808 "section".
BTW, i'm going to have 2 output transformers, with Raa=2.5kOhm, and the secondary is 4ohm. They were made for tha APX100.
the apx100's power would be good for me, becouse I have 8ohm speakers, so I could have about 50W output power.
edl, what do you think of APX100? Is it worth building a modified APX100?
De miert nem magyarul tarsalgunk?
hi edl,
your link seems to be broken or i do not understand the lingo. can you send me schematic at tonytecson@gmail.com?
thanks a lot.
Here it is: http://sziget.mine.nu/~danko/aramkor/tube-amp/apx100_rajz.jpg
Enjoy!
btw, I have "coupled" the Williamson-amplifier, and two PL509 tubes
Yesterday I fired it up, but the amp was oscillating, and maybe becouse of this, my switched mode PSU went wrong.
http://sziget.mine.nu/~danko/aramkor/Screenshot-239.png
this is the schematic.
The B+ es 300V, becouse the PL509s are connected in triode mode, and becouse of this (300V B+), the drive-stage have to be redesigned.
The output power (I hope ) will be about 30-40W.
Here are the idle voltages of the driving stage:
http://sziget.mine.nu/~danko/aramkor/Screenshot-240.png
Enjoy!
btw, I have "coupled" the Williamson-amplifier, and two PL509 tubes
Yesterday I fired it up, but the amp was oscillating, and maybe becouse of this, my switched mode PSU went wrong.
http://sziget.mine.nu/~danko/aramkor/Screenshot-239.png
this is the schematic.
The B+ es 300V, becouse the PL509s are connected in triode mode, and becouse of this (300V B+), the drive-stage have to be redesigned.
The output power (I hope
) will be about 30-40W.Here are the idle voltages of the driving stage:
http://sziget.mine.nu/~danko/aramkor/Screenshot-240.png
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