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Hits: 1306 Replies: 3
TUBE 19BR5
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Júlio Branco
03.Jun.19 |
1
Hello radiofriendes
This tube can not be directly replaced by the EM80 tube, ie the filament voltage (between pins 4 and 5) is 19 volts, although it has the same current. Thank you very much Júlio Branco |
Michael Watterson
04.Jun.19 |
2
It's 100 mA, basically a UM80 for series wired heaters. The EM80 is nearly 300 mA (270 mA), for parallel 6.3V operation. Are you wanting to put 19BR5 in a radio with only 6.3V parallel heater supply? There are cheap NOS Russian 6e1c (6Е1П) available from Latvia and Ukraine. If you really want to run it of 6.3V, a voltage tripler using 1000uF 25V capacitors and 1N4002 or 1N4007 rectifiers might give about 17V, which might be enough. Running an EM80 / 6e1c (6Е1П) in a radio intended for the 19BR5 / UM80 would need a transformer as the series heater supply is 100 mA and thus the EM80 might only have two volts on it (100 mA rather than 270mA current). |
Giuseppe Feniello
04.Jun.19 |
3
hello, if you have a radio with voltage selector you can take 20v from 140 and 160v on the power trafo, and put a 10 ohm ( 0,5watts )resistor in series with the filament of the 19BR5....BUT TAKE CARE!!, you do not have insulation from the mains on the filament.... |
Michael Watterson
04.Jun.19 |
4
I think that would exceed the insulation resistance of the heater to the cathode. Even on a "live" chassis series filament / heater radio, the UM80 / 19BR5 should not be at the HT end. Also if the radio is normally not a live chassis, even if the transformer taps are at the neutral, the isolation between any chassis part such as gram/pu, earth, external speaker, knobs, trim etc would be compromised. So for a normally transformer isolated 6.3V parallel heaters it's not worth trying to use the 19BR5 as a transformer for 19V (18V will do) or a voltage trippler from 6.3V AC to 17V to 19V DC is more expensive than buying NOS Russian EM80 equivalents 6BR5 6e1c etc from Ukraine or Latvia on ebay. Save the 19BR5 for a radio that has series 100mA heaters/filaments (UM80 or 19BR5 originally). |
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