JS,

I have used the NE-2 Neon Bulb and 10K Ohm Risistor with my portable
radio Antenna "GIZMOE" Connector Box to protect the external antenna
inputs of several radios.

I have also used a double pairing of Forward & Reverse Diodes to act
as a low voltage shunts along with the NE-2 Neon Bulb as the Higher
Voltage Shunt and the 10K Ohm Resistor for Static Bleed-Off.

G = Ground
* = Space
| = Bus Wire
- = Connector Wire
^ = Pot's Wiper

G**********A = External Antenna
|----o)----| = NE-2 Neon Bulb or Gas Discharge Tube
|**********|
|--|--|--| = Forward Diodes
|**********|
|--|--|--| = Reverse Diodes
|**********|
|--/\/\/\--| = 10K Ohm Resistor / Potentiometer
|****^****** = Pot's Center Wiper
|****|******
|****------|
G**********R = Radio's External Antenna Input


The INPUT Side of the Gizmoe has an SO-237 Connector plus an Antenna
and Ground Terminals.

The OUTPUT Side of the Gizmoe has a 1/8" Stereo Plug with the
Tip=Antenna and the Rear Barrel = Ground (Center Section is not used)
plus Antenna and Ground Terminals.

NOTE: Using a 10K Ohm Potentiometer with the Center Arm "Wiper" as an
output to the Radio's Antenna Input allows for the adjustment of the
external antennas signal level to reduce overloading the portable
radios RF (Front End) Input. Functions as an External RF Gain Control
for the radio.

FWIW: Using a Gas Discharge Tube {GDT} instead of an NE-2 Neon Bulb
is recommended.
- - - The GDT's are reported to handle more current and voltage.


jm2cw ~ RHF
..
..
= = = "Joe Strain"
= = = wrote in message .com...
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


"-=jd=-" wrote in message
.. .
I'm a newcomer to SWL and I've been perusing the boards and the various
sites. Lots of interesting info to be found all over - perhaps too much
info. I'm quite possibly a good example of the adage that a little
knowledge can sometimes be a dangerous thing.

So, I'm thinking of the following to reduce noise while listening inside
the house (with a Grundig YB400PE):

The plan is to string 100-feet of #14 wire from a 14-foot post next to
the house to a tree (about 130-feet away and 30-feet up) with about 30-
feet +/- of rope on the post end of the wire. I'll connect coax from the
end of the wire to a project box; from the project box to a ground-rod;
from the ground-rod to the receiver.

About the project box:
It was raining and I was bored. I took the anti-static design from the
AMANDX site (www.angelfire.com/mb/amandx/static.html)

And the 9:1 balun from the hard-core-dx/nordicdx site (http://www.hard-
core-dx.com/nordicdx/antenna/feed/9_1balun.html)

And I've combined both designs into one box. The way I did it was to
connect the capacitor from the static filter to the antenna side of the
balun (hope that makes sense). Oh, it looks like hell, but I'm thinking
it might actually work ok.

I'm hoping to string it all up as soon as Tropical Storm "Bill" blows
through and see if there's any difference from the built-in and wind-up
antennas. Given that I am (admittedly) a totally green newbie and have
*no* clue about the theory behind the random wire antennas, the anti-
static filter or baluns, I'm wondering if anyone may have any advice they
may like to offer regarding what I have planed, other than gales of
derisive laughter...

JD
--
"Who are you going to believe, me or your lyin' eyes?" -Groucho Marx