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![]() Joe Strain wrote: I am doing the same thing myself, but let's think about the anti-static feature which uses a Ne-2 bulb a 10K resistor and IIRC a .01 capacitor The NE-2 is a NEON tube...They don't conduct, they FIRE like a Thyratron, they are gas discharge tubes...like a stone age Zener diode. The NE-2 ( when I used them in strobe-light power supplies, fired at 65 volts and until it reached 65 volts, it did NOTHING. Reading recent references I see it is listed as a 105-125 V device...perhaps that's for optimum "brightness"...I just know it FIRES at 65 ac volts. at any rate the 10K resistor is a good order of magnitude too low in my opinion...The reference ( a xeroxed page from a catalog listing all the neon tubes characteristics) says the bulb needs a 200K resistor for a 65V AC firing voltage (RF is AC) or 90V DC firing voltage. Can we have some practical experience here from the "listeners" about whether the resistors should be 10K or 200 K ? Yodar 10k is a good value for the resistor. In this application the resistor is in parallel with the bulb. Its purpose is to bleed off any static that generates. In this case, lower is better, but you want to keep the value well above ( 10X ) the impedance of whatever is connected. When there is a nearby strike, more voltage will be generated on the antenna. When the voltage exceeds 90 volts, the lamp fires. It discharges the antenna until the voltages drops below 65 volts. After that, the resistor bleeds off the rest. When using the lamp as a pilot light, the resistor is in series with the bulb. This is done to limit current. Too much current and the bulb's life is shortened. As another poster mentioned, a balun tends to put everything at ground potential anyway. None of this is sufficient to handle a direct strike. Also a sufficiently large nearby strike could still cause damage to a radio. Enjoy Craig |
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