EM-84 vs. EM-840 in 101-R/4000R

larryderouin

I'm VERTICAL and Breathing...most of the time.
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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.

101-R + 4000R voltages.jpg
Thanks

Larry
 

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Last edited:
When I first moved to Switzerland in 1990 the first word I learned in German was VERBOTEN.
Larry, if you have the patience to type the German text into Google Translate, you will get what you are looking for.
The funny letters with the two dots on top are written in English as: ä is ae, ü is ue, and ö is oe.
- Tom
 
Looks like the EM84 might be very slightly more sensitive than the EM840. It might close a wee bit more. Don't really think it would be a problem though.
 
Thanks Tom. I can muddle thru some of it by matching up the symbols, and doing some creative mis-spelling in my head. Every time I hear VERBOTEN, I see an Image of Sgt. SCHULTZ on Hogans Heroes (yeah I watched it 1st run as a kid).LOL.

I've got 3rd or 4th cousins on my mother's side in the south of Switzerland. But I can't remember the name of the town.
 
Gadget; I was thinking pretty much the same, but I needed some backing. I can always try an em-84 in it, (when I get the EF86's and the EBF89). If it closes up too far I can see if I can find an em840.
 
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