Page 1. Page 2. Page 3. Page 4. Page 5. Page 6. Page 7. Page 8. The is described as being for use in cascode circuits and as a multivibrator and cathode follower in References: Datasheet & private correspondence. E88CC-TK TUBE DATA SHEET. Mechanical. Also known as the , the E88CC was originally targeted for test equipment and radar. The E88CC has.
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Next read note 7 And there is the rub. What do you or those costumers mean with tube life? ACHiPo on 27 Jan Steve, You’re playing well within bounds as far dztasheet I’m concerned, and I’m learning a heck of a lot in the datasheft, so thank you. Here is the bias adjust procedure for the VT50 http: A few reasons why two sections inside of one envelope will cause the two sections to measure differently. And there is the rub.
OPERATING POINT LIMITATIONS
Cookies help us provide you a better browsing experience. With a constant grid to cathode voltage, if we change the plate to cathode voltage, the plate current will change. If the filament or cathode is operated continuously with a higher voltage than that recommended, some of the coating material is evaporated and permanently lost, thus reducing the life of the valve. My preamp is a Sonic Frontiers Line One.
See numbers 4 and 5 for setting the input and driver tubes plate voltage on the PDF Link provided.
TDSL Tube data 
Let’s just consider the triode, and keep things simple for ease in understanding. As far as transconductance being reduced, reduced transconductance will increase the plate resistance, thus lowering the high frequency response. If the filament dataxheet heater is operated for long periods at reduced voltages, the effect is a reduction in emission, but no damage is generally done to the valve unless the cathode currents are sufficient to exhaust the “space charge.
I think I understand the reason why when looking at the VT50 circuit design of the driver tube. There is no problem supplying 6. AC Yes but it is well within the context of the thread. Designing a circuit to operate around dataseet cut-off point is not advisable if a good linearity of an amplifier is required. My concerns are the safety in case dataaheet catastrophic failure of the valve occurs, the less good performance are acceptable to me.
Maybe a bit better then the i say catasheet but after h it is really a lot less then it was new. Manufacturer’s specs will be conservative. One matched pair low noise per channel. The datasheet also specifies two additional, and connected, restrictions for the choice of the bias point.
What I discovered was for a tube whose sections MICROMHOS tested very close or the same that tube was the best candidate for achieving the best equal bias voltage for the plates of each section of the dual triode tube.
Dtaasheet 1section 2 No way this tube could be biased in the VT50 as a driver tube let alone an input tube.
The plate structure may not be placed exactly the same in relation to the cathode and grid. Steve on 26 Jan So it is better not to use 6v but a little higher. These tubes were also bought as closely matched low noise tubes from well respected tube vendors. The cathode material may be slightly warped, thus the relationship between each cathode to grid and plate may be slightly different. Again, just for a triode. However, over the years I have not keep a time clock on tubes hours.
Rp is the change in plate to cathode voltage with a change in plate current,, with a constant grid to cathode voltage. As far as sections not matching, let’s check datashee the variables.
Datasehet string will be long gone. Differences in Plate resistance? FullRangeMan on 26 Jan The Va b is the maximum voltage to which ‘s anode is allowed to swing under signal or cold conditions and is about VDC for the The final limitation is the maximum allowable cathode current Ic.
The maximum allowable cathode current for the tube is mA. It’s been a few years since I listened to it critically with good tubes, but I don’t remember it sounding like this. So, where does close matching of GM come into play?
6922/ECC88/E88CC double triode
However, there are extenuating circumstances involving heavy plate current and increased frequencies into the high MHz, and depending upon the tube, in which transit time becomes a problem. You can read some reviews of one of my poor designs here.
Normally one thinks of resistance as being voltage divided by current equals resistance. Steve on 27 Jan Steve on 25 Jan The lower the plate current, the less the cathode is cooled by electrons leaving.
It seems to support Brent Jesse’s and Kevin’s position that 7DJ8 tube life could be longer at the lower heater voltage, but FRM and E55’s contention that it’s not good practice are supported as well. The machine winding the grid wire for each section has tolerances, thus the grid wire for each triode section can and usually is a little different.
To know the tube life you have to measure the tube S, Ri, mu etcetera Quote from: