The 12BE6 is a heptode or pentagrid valve. The heptode is classically pins, is 47 mm tall. References: Datasheet &. Type 12BE6 was first introduced in 12BA6. 12BE6. Page 1. !! C. CE ELECTRONICS. 12BABE6. – DESCRIPTION AND RATING. BA6. 12BA6 Remote-Cutoff Pentode. The 12BA6 is a. electron Tube Data sheets – 1. 12BE6, General Electric, H, ( bytes). 12BE6, Brimar, H, ( bytes). 12BE6 photo, RCA (RC30).
|Published (Last):||3 September 2015|
|PDF File Size:||17.12 Mb|
|ePub File Size:||15.49 Mb|
|Price:||Free* [*Free Regsitration Required]|
One of the things I enjoy when repairing my tube radios, is getting them to perform as well as they can.
12BE6, Tube 12BE6; Röhre 12BE6 ID, Pentagrid-Converter (
The 12BA7 gives twice the conversion transconductance of the other tubes. Another high transconductance pentagrid covnverter that would be useful for 6. The 7pin plug for the 12BABE6 socket adapter is hard to find. I tried reusing the glass button from a dead 7 pin tube, but the tube metal would not solder. The octal plug is very easy to reclaim from a dead octal tube. The 9 pin socket of the 12BA7 even fits very nicely inside bakelite plug. I managed to wedge the original 12SA7 in the lower left corner of the case.
My method to deal with this difference in capacitance is a short procedure:. You should noticed substantially stronger volume than before, or a more negative AVC voltage. I made a casual measurement of the performance improvement with the Teletone with a DC measurement of the AGC line:. This is nearly a factor of 4 improvement in output signal. Some of this may be simply a result of improved detector efficiency, when running with a stronger signal.
The improvement for both radios was also quite obvious to my ears. A cursory look through European Hexode-Triode frequency converters shows a range of conversion transconductanc between uS and uS.
Perhaps someone knows of a “hot” Hexode-Triode. I will try it when I have a 12BA7.
It was used on the Hallicrafters Echophone They used a 12SG7 at the IF amp. Instead of 1be6 12SK7. I tried it in a Emerson with very good success.
12BA7 to 12BE6 or 12SA7
The socket connections are not exactly the same. The cathode is tied to the suppressor grid. They are pins 3 and 5 that in some sets are short circuited. Besides this they are direct replacement. Transconductance for the 12SG7 is umhos. For the 12SK7 is umhos at the same conditions. Best regards, Jose Vigil ell. Thanks for the reference to the 12SG7 pentode.
I was a bit surprised with the results. It appears that the gm advantage of the 12SG7 over the 12SK7 is valid only at the lowest control grid bias level.
The difference in performance between the two tubes was not as obvious as it was with 12BA7 vs 12SA7 pentagrid mixers mentioned above, despite a two-to-one ratio in transconductances in the pentodes. I compared reception for three different stations:. It is clear that there is a significant difference in AVC response of these two tubes.
This implies a sharper AGC action at the expense of tolerating smaller maximum signals at a given distortion.
The AVC compression is tighter with the 12SG7, and the low signal gain is twice, as promised by the higher transconductance. Thanks for the information of the measured voltages. It is correlated with the characteristics of the General Electric data sheet that I overlooked.
For about the same plate and screen voltages, the cut off grid voltage is almost three times larger on the 12SK7. You are right on at the applications. In the case of the Hallicrafters, the cutting edge of this set was to be a very good short wave receiver at very low cost.
It has an accurate calibrated dial and separate spread control. I will take a close up photo of the dial to upload at 12ve6 model page. About the use in a medium wave set such as the Emerson It has a clear advantage for weak signals. Perhaps with nearby stations the crossover distortion is a problem. The contrast in cutoff voltages you report illustrates clearly the different AGC action for these two tubes.
I looked for the same type of log scale plot that was used in the 12SK7 data sheet, in the data sheets datasueet the other tubes, but could not find any.
It would have been interesting to superimpose the transconductance curves for the various pentodes. I started on the 12SG7 tube page and followed some of the radio links. RCA mi from The surprise is that this radio has a mA series heater string, but the 6SB7Y at it’s front end requires 6.
The clever trick to supply the additional current for the 6SB7Y heater is to wire it’s heater in series with the other heaters, as well as in series with the rectifier path. In other words, all the current into the radio must pass through the 6SB7Y heater.
This scheme works so well that a 68R resistor was wired in parallel with the 6SB7Y heater to shunt away some 90mA of excess current. The total current draw for this radio is mA rms and mA of this current passes through the 6SB7Y heater.
Some of the extra current dqtasheet this radio comes from the 35L6 pentode pair used in parallel at the output. The specified conversion transconductance for these three pentagrid converters is as follows: The conversion diagrams show a fairly straight-forward method of wiring up socket adapters.
Hot rodding AA5 radios
Click on these thumbnails for wiring detail: My method to deal with this difference in capacitance is a short procedure: I made a casual measurement of the performance improvement with the Teletone with a DC measurement of the AGC line: To thank the Author because you find the post helpful or well done. It is a charm to tune. Best regards, Jose from To thank the Author because you find the post helpful or well datsheet. Other candidate pentodes with a compatible octal pinout and remote cutoff might datashewt The 12SG7 was often used as the RF preamp in some designs: