"Dave" wrote in message
...

"Yukio YANO" wrote in message
news:j3BKh.25152$DN.7632@pd7urf2no...
Dave wrote:
I saw somewhere that you could use an NE-2 bulb between the antenna
"hot" lead and ground as a static discharge device for a receiver, but
can't find an NE-2 and don't know anything about neon bulbs. Anybody
know if a standard neon bulb rated at 125 VAC could be used in this
manner? Or how I could test it? I'm thinking about charging up a 50V
electrolytic capacitor and hitting the bulb with that, to see if it
discharges the cap. I have a .22uF 630V mylar cap between the antenna
and the input to the tuner because the 35V disc I had there got blown,
so I know that static can be a problem with my setup even though it is
grounded at two points.
Would welcome any ideas anyone has on how to make this work...

Thanks,

Dave


Most CB radios use a pair of back to back diodes across the receiver
input. I also recall the input of the ECG amplifiers also have the same
network to protect the Input circuitry from being blasted by the Pulse
from Defibrillator Paddles (1~5 KV.). These Back to back Diodes Clamp
the Voltage to the Forward Voltage Drop of the Diodes in question at
around 0.6 Volts. This circuit works much better and for cheaper than the
NE2 at ~60 Volts. If Static Electricity (lightning) is a problem at a
specific Frequency, a Grounded 1/4 wavelength shorted Stub could be wired
into the Feedline to present a DC ground to the entire antenna system.

Yukio YANO
VE5YS

Of course! Back to back diodes! Why didn't I think of that? Thank you,
thank you, thank you. How obvious!

But is there any way that I could still use my neon bulb to let me know if
a pulse of high-voltage static hits the input to the receiver? I would
love it if there were some way to make that still work...

73's


Dave


Question on this last note: What if I put the back to back diodes in series
with a 100K resistor, and they together in parrallel with the neon bulb.
Would that slow the discharge of a fairly large static pulse enough to light
the neon bulb, even briefly? I have the input to the receiver protected by
a fairly high-voltage (non-electrolytic) capacitor, so I'm not too worried
about the slowed-down pulse getting through to the rest of the circuit. And
if it did get through it would find an air-gap transmitting variable
capacitor next in line as the tuning cap. Is this a dumb idea, or might it
behave as I desire? Any ideas?

Thanks,

Dave