Thanks for everyone's input but my main question out of all this would the FLAMEPROOF resistors be ok in that circuit. I am sure the wattage and ohm.s value would work. I thought the flame proof resistors had a coil inside the resistor. With out busting one up to see is this true, and if so would it cause problems in this circuit. The shunt I am talking about is SH3 on the grid of the clamp tube.
Thanks John W9BFO
John,
Yes, we are talking about
SH3.
I found a later Ranger II schematic so does the first schematic in the PDF below follow the circuit that you have, or does your circuit follow the second schematic?
I also included some meter protection diodes.
What I was trying to convey was the two 10 ohm 2 Watt resistors are OVERKILL, that is, you only need a 20 ohm 1/2W resistor at the most.
If you have an open R14 SH3, then you have more problems than just that one resistor.You could use a 22 ohm 1/2 Watt resistor with a 10% loss in accuracy, that is, your grid current would only read about 10% higher.
If you have a 22 ohm 1/2W carbon composition or carbon film resistor you can parallel it with a 220 ohm carbon composition or carbon film resistor to equal exactly 20 ohms.
If the resistors that you have are inductive, yes it may cause problems.
The Ranger parts list lists the
R14 SH3 as a 20 ohm 1/2W carbon resistor. It does not go to the Clamp tube grid.
R37 (22k or 27k, 1W, depending on the schematic) feeds the clamp tube grid so the total voltage between ground and across R37 and R14 in series feeds the clamp tube grid.
With 2.5 mA of Final control grid current, the clamp tube control grid normally sees about -55.05 volts. If RF excitation fails, the clamp tube control grid goes positive and the clamp tube plate drops the Final's screen voltage across R15 so the 6146's plate current does not become excessive.
Phil - AC0OB