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Dak Mark IX Help

siltronix_man

Member
Jan 19, 2012
29
3
13
Was wondering if there is a plate current adjustment for this radio Put in fresh el84 tubes and while keyed down plate current drops I know the plate current is supposed to be set at 60ma im seeing about 20 at best put in brand new tubes any help appreciated
 

What does your wattmeter indicate for the deadkey?

I would use an ohm meter and check resistors r711 = 10 ohm, r708 = 10 ohm, r706 = 4.7k ohm, and r709 = 180 ohm.
Any of these resistors being off value significantly could cause this problem.
Additionally, the following from the service manual:
Located behind the P.C. board containing the VACCUM tubes is a shielded can containing the final R.F. amplifler tank circuit. There are two variable capacitors are mounted on top of tank coil. Peak these for maximum output. These capacitors interact so it will be necessary to adjust and readjust until maximum reading is obtained on R.F. output meter.
 

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  • @ heartbreaker3473:
    Hello gentlemen and Ladies. I have the dreaded RCI-2990 receive issue where my radio gets distorted when people get close to my location. I found the C90 Capacitor, but I can not for the life of me find the C89 capacitor. Can or does anyone have a picture of the exact location of C89 ? Thank you in advance, Wes
  • @ AudioShockwav:
    Wes, it's better if you start a thread on the main forum, more people are going to see your question.
  • @ heartbreaker3473:
    Okay, sorry, will put in a forum
  • @ heartbreaker3473:
    I put it in the general disscution help area and started a new thread. Thank you for letting me know.