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

Aren't all parts of those 9:1 baluns at DC ground already?

If your co-ax is well grounded you don't need the capacitor.

On Tue, 01 Jul 2003 02:56:06 -0000, "-=jd=-" wrote:

core-dx.com/nordicdx/antenna/feed/9_1balun.htm

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

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

RHF wrote:

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.


Neon tubes "fire" at around 80-110V. Can your front end take this? Older tube rigs
can, not sure I would bet on a FET front end.
A pair of diodes right on the input can be disastrous. They are a nonlinear device,
easily driven into generating all sorts of mixing products- as they are right at the
antenna, everything from local AM, FM and TV will be seen by the diodes.

Dale W4OP

Dale Parfitt wrote:

RHF wrote:

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.


Neon tubes "fire" at around 80-110V. Can your front end take this? Older tube rigs
can, not sure I would bet on a FET front end.
A pair of diodes right on the input can be disastrous. They are a nonlinear device,
easily driven into generating all sorts of mixing products- as they are right at the
antenna, everything from local AM, FM and TV will be seen by the diodes.

Dale W4OP

Some very good points Dale.

In article ,
N8KDV wrote:

Dale Parfitt wrote:

RHF wrote:

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.


Neon tubes "fire" at around 80-110V. Can your front end take this? Older
tube rigs
can, not sure I would bet on a FET front end.
A pair of diodes right on the input can be disastrous. They are a nonlinear
device,
easily driven into generating all sorts of mixing products- as they are
right at the
antenna, everything from local AM, FM and TV will be seen by the diodes.

Dale W4OP

Some very good points Dale.

He is more than right. Diodes are used as broadband white noise sources
in test equipment.

--
Telamon
Ventura, California

DP,

1. When the radio is not being used the POT is set to Zero and the
Receiver's Antenna Input is Shorted-Out and Grounded.

2. This is a 'set' of both Forward and Reverse Diodes Dual [Doubled]

--|--|--

--|--|--

If you have enough wide band RF signal levels to make these dual
diodes work then with a modern solid state radio most likely you have
major front-end overload in the radio.


~ RHF
..
..
= = = Dale Parfitt
= = = wrote in message ...
RHF wrote:

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.


Neon tubes "fire" at around 80-110V. Can your front end take this? Older tube rigs
can, not sure I would bet on a FET front end.
A pair of diodes right on the input can be disastrous. They are a nonlinear device,
easily driven into generating all sorts of mixing products- as they are right at the
antenna, everything from local AM, FM and TV will be seen by the diodes.

Dale W4OP

RHF wrote:

DP,

1. When the radio is not being used the POT is set to Zero and the
Receiver's Antenna Input is Shorted-Out and Grounded.

2. This is a 'set' of both Forward and Reverse Diodes Dual [Doubled]

--|--|--

--|--|--

If you have enough wide band RF signal levels to make these dual
diodes work then with a modern solid state radio most likely you have
major front-end overload in the radio.

~ RHF

Didn't they put this same sort of setup in one of the NRD's (JRC) of yore, only to
discover it caused intermod and had to be removed.?


.
.
= = = Dale Parfitt
= = = wrote in message ...
RHF wrote:

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.


Neon tubes "fire" at around 80-110V. Can your front end take this? Older tube rigs
can, not sure I would bet on a FET front end.
A pair of diodes right on the input can be disastrous. They are a nonlinear device,
easily driven into generating all sorts of mixing products- as they are right at the
antenna, everything from local AM, FM and TV will be seen by the diodes.

Dale W4OP

N8KDV wrote:

RHF wrote:

DP,

1. When the radio is not being used the POT is set to Zero and the
Receiver's Antenna Input is Shorted-Out and Grounded.

2. This is a 'set' of both Forward and Reverse Diodes Dual [Doubled]

--|--|--

--|--|--

If you have enough wide band RF signal levels to make these dual
diodes work then with a modern solid state radio most likely you have
major front-end overload in the radio.


They don't have to be driven into conduction just into the square law region.



Didn't they put this same sort of setup in one of the NRD's (JRC) of yore, only to
discover it caused intermod and had to be removed.?


Some years back, an amateur mfg had varicaps tuning a front end filter- IP3 characteristic
was horrible. The next generation got rid of the idea.

Dale W4OP