AMRAD LF Active Antenna Question

[Andre Kesteloot]

whoops, my unfinished msg went out without my permission :-)

Anyway get two or three additional NE-2 bulbs  (at $0.54 each, you can't go
wrong :-), and learn how useful they can be.

With two capacitors and two resistors, you can build a basic multivibrator
etc.
Install those two bulbs behind an ugly mask, and you will have monster
blinking his eyes, etc.

see for instance  http://www.tinaja.com/glib/muse136.pdf

Good luck
73
André


On Sun, Nov 2, 2014 at 5:35 PM, Andre Kesteloot <akesteloot at gmail.com>
wrote:

> Hello Mark,
>
> yes indeed, as Rob wrote, the part you need is a Neon bulb type NE-2.
> You will find it at Digi-Key for 54 cents.
> Digi Key does not have a minimum order and will mail small items First
> Mail in a small envelope.
>
> *http://www.digikey.com/product-detail/en/A1A/A1A-ND/4176016
> <http://www.digikey.com/product-detail/en/A1A/A1A-ND/4176016>*
>
> ​This neon bulb looks like a high impedance (open circuit) until you apply
> between 70 and 90v across it, as which time, the neon gas in the envelope
> starts conducting. It then presents an extremely low resistance
> (essentially a short-circuit) between the two electrodes.
>
> As it is connected, if a high static voltage (thunderstorms, ...) were to
> appear at the antenna, the bulb would strike and the static voltage would
> be shorted to ground. Upon disappearance of that high volagte spike, the
> neon tube would stop conducting, and the signal fro the antenna would again
> be amplified by the received.
>
>
>
> On Sun, Nov 2, 2014 at 4:53 PM, Robert Seastrom <rs at seastrom.com> wrote:
>
>>
>> On Nov 2, 2014, at 4:37 PM, Mark Fancher <mark.fancher at twc.com> wrote:
>>
>> > Looks like the LED specified for the antenna (not the power supply)
>> isn’t offered by Radioshack anymore.  Will this thing work without that LED
>> or is it required?
>>
>> Hi Mark,
>>
>> I just looked at the schematic and I don't see an LED in the antenna
>> amplifier schematic.
>>
>> Attention to
>> http://www.arrl.org/files/file/Technology/tis/info/pdf/0109031.pdf
>>
>> Are you perchance referring to "DS1NE-2 neon lamp (272-1102)" in the
>> schematic on page 34?
>>
>> If so, that's actually a neon indicator bulb and at a guess it's there to
>> provide a static discharge path so that the first thunderstorm within 10
>> miles doesn't send Q1 to the great parts bin in the sky.
>>
>> There seem to be NOS NE-2 neon bulbs on eBay.  Guess those are one of
>> those things that used to be super common and are now hard to find.
>>
>> The original authors are around and subscribed to the list; perhaps they
>> will chime in.
>>
>> 73,
>>
>> de AI4UC
>>
>>
>>
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>>
>
>
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