QUESTION: Does anyone have a tuner or Tuner/preamp that uses a EM-840? Fisher installed an EM-84 on the AM band but got cute, and changed up the tube to an EM-840 on the FM BAND. And the EM-840 is really DIM. I looked last night for about 2 hours and only found one cross reference that said the EM-84 and EM-840 are interchangeable. Found the Data Sheets and the specs. The following are the only differences I could find comparing the data sheets.
EM-84.....................EM-840
210ma.....................270ma ........Heater Current
-21v...........................-22v...........Grid Supply voltage
1.0-1.8ma................1.1-1.6ma Luminescent screen Current
Otherwise they look to be identical. Unfortunately the EM840 Data sheet is in German and my German consists of YA, Nein, and YA'Wohl Herr Colonel. (Yeah I watched Hogan's Heroes as a kid....) I'm thinking I can use a EM-84 in place of the 840 with little to no problems, but going the other way may have problems with the heater current. What say you guys. Data sheets Below.
On the 101-R/4000R the EM-84 is V11 and the EM840 is V12. There are different voltges for Pins 7 & 9. 8 volts difference. Don't know if this will hurt a EM-84 or not. This is the Voltage test chart from the 101-R manual.
Thanks
Larry
EM-84.....................EM-840
210ma.....................270ma ........Heater Current
-21v...........................-22v...........Grid Supply voltage
1.0-1.8ma................1.1-1.6ma Luminescent screen Current
Otherwise they look to be identical. Unfortunately the EM840 Data sheet is in German and my German consists of YA, Nein, and YA'Wohl Herr Colonel. (Yeah I watched Hogan's Heroes as a kid....) I'm thinking I can use a EM-84 in place of the 840 with little to no problems, but going the other way may have problems with the heater current. What say you guys. Data sheets Below.
On the 101-R/4000R the EM-84 is V11 and the EM840 is V12. There are different voltges for Pins 7 & 9. 8 volts difference. Don't know if this will hurt a EM-84 or not. This is the Voltage test chart from the 101-R manual.
Thanks
Larry
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