On Feb 15, 9:43*am, bpnjensen wrote:
On Feb 15, 9:08*am, Bob Dobbs wrote:

dave wrote:

http://www.mfjenterprises.com/pictures/MFJ-270.jpg

Looks like the gas discharge type I have.
Somewhere I heard someone say that they go shorted when hit,
like a MOV, but that seems counterintuitive and it seems more likely
that they would just go permanently open by out gassing.
What's your opinion on this?

My DX-Ultra has a proprietary gas discharge arc-plug in its core.
Alpha Delta says that after several years of significant static, it
can get weak and the antenna won't function as well. *Just to be anal,
I put in a new one about 6 years ago, and it's worked about the same
before and after and ever since.

-wrt- Gas Discharge Arc-Plug [G-DAP]
* If it's OK You Won't Notice It In Receive.
* If it's Blown You Won't Notice It In Receive.
* If it's Shorted You Will Notice It In Receive.

Note 99+% of the time if a G-DAP has done it's 'J-O-B' :
It is Blown -and- The Blown G-DAP is Useless.

Very seldom do G-DAP's Short; if at all.

-hint- One way that you might suspect that the G-DAP
is 'Shorted' is if the Paint on your Antenna Switch is
.. . . Burnt. ;;-}} ~ RHF

On Feb 15, 4:01*pm, Bob Dobbs wrote:
dave wrote:
On 02/15/2011 09:08 AM, Bob Dobbs wrote:
dave wrote:

http://www.mfjenterprises.com/pictures/MFJ-270.jpg

Looks like the gas discharge type I have.
Somewhere I heard someone say that they go shorted when hit,
like a MOV, but that seems counterintuitive and it seems more likely
that they would just go permanently open by out gassing.
What's your opinion on this?

The instructions point out that this happens and that you can get back
on the air by removing the replaceable arc pill thingy. I suspect a
charge big enough to fuse the gap would have been a front-end killer. I
was a firm believer in Power MOVs when I was a station engineer in South
Texas.

What about the gaseous content fuses into a short?
I agree that MOVs do fuse the junction, but they are solid state,
whereas I don't see how gaseous content becomes permanently conductive.

Maybe it forms a coating on the inside of the plug?

On 2/15/2011 4:28 PM, wrote:

On the subject of front end protection. Some very good (old-time)
designs contained a simple neon light (120vac) across the antenna
terminals . Such modestly priced extra protection never hurts . Gas
discharge tube type is much better,though .

Don't want to use a 120 VAC neon bulb...it has a series resistor. Just
use a plain NE-2 neon bulb without any series resistor, it fires at 60
volts and IS by definition a "gas discharge" tube.

On 2/14/2011 9:01 PM, RHF wrote:

-where-as-these-
Low-cost Plastic Egg Insulators in a Bag of 10
only Cost around 60 Cents a piece.

Well, you really don't want egg insulators for this application --
that's not what they are designed for.

Their intended use is for guy wires, to break them up into non-resonant
lengths for towers that will be used to support a transmitting antenna.
Furthermore, if the egg insulator should happen to break, the sections
of guy wire will still be looped together, still providing mechanical
integrity.

The insulator you should be talking about is the classic plastic or
glass ribbed insulator.

On 02/15/2011 05:18 PM, Joe from Kokomo wrote:
On 2/14/2011 9:01 PM, RHF wrote:

-where-as-these-
Low-cost Plastic Egg Insulators in a Bag of 10
only Cost around 60 Cents a piece.

Well, you really don't want egg insulators for this application --
that's not what they are designed for.

Their intended use is for guy wires, to break them up into non-resonant
lengths for towers that will be used to support a transmitting antenna.
Furthermore, if the egg insulator should happen to break, the sections
of guy wire will still be looped together, still providing mechanical
integrity.

The insulator you should be talking about is the classic plastic or
glass ribbed insulator.

On Feb 15, 4:01*pm, Bob Dobbs wrote:
dave wrote:
On 02/15/2011 09:08 AM, Bob Dobbs wrote:
dave wrote:

http://www.mfjenterprises.com/pictures/MFJ-270.jpg

Looks like the gas discharge type I have.
Somewhere I heard someone say that they go shorted when hit,
like a MOV, but that seems counterintuitive and it seems more likely
that they would just go permanently open by out gassing.
What's your opinion on this?

The instructions point out that this happens and that you can get back
on the air by removing the replaceable arc pill thingy. I suspect a
charge big enough to fuse the gap would have been a front-end killer. I
was a firm believer in Power MOVs when I was a station engineer in South
Texas.

- What about the gaseous content fuses into a short?
- I agree that MOVs do fuse the junction, but they are
- solid state, whereas I don't see how gaseous content
- becomes permanently conductive.

"BD" The 'gaseous content' does not
-but- The "Container" itself may well.

*IF* The Paint on your Antenna Switch is Burnt . . .
-mission-control-we-got-a-problem-;;-}}- ~ RHF

On Feb 15, 4:48*pm, bpnjensen wrote:
On Feb 15, 4:01*pm, Bob Dobbs wrote:



dave wrote:
On 02/15/2011 09:08 AM, Bob Dobbs wrote:
dave wrote:

http://www.mfjenterprises.com/pictures/MFJ-270.jpg

Looks like the gas discharge type I have.
Somewhere I heard someone say that they go shorted when hit,
like a MOV, but that seems counterintuitive and it seems more likely
that they would just go permanently open by out gassing.
What's your opinion on this?

The instructions point out that this happens and that you can get back
on the air by removing the replaceable arc pill thingy. I suspect a
charge big enough to fuse the gap would have been a front-end killer. I
was a firm believer in Power MOVs when I was a station engineer in South
Texas.

What about the gaseous content fuses into a short?
I agree that MOVs do fuse the junction, but they are solid state,
whereas I don't see how gaseous content becomes permanently conductive.

- Maybe it forms a coating on the inside of the plug?

Only -if- The Material ofl Container Ionizes with the
Gas and forms a Compound that is then Deposited
on the interior surface that is conductive.

More likely -if- the Material/Metal got so HOT as to
Ionize it would first flow and bridge the gap by itself.

****remember***
*IF* The Paint on your Antenna Switch is Burnt . . .
-mission-control-we-got-a-problem-;;-}}- ~ RHF

On 02/15/2011 07:09 PM, RHF wrote:

Hey Now here Is A Use For An Empty Mason Jar
as a Lightning Protector -after- I Say After !

You Have Remove ALL {Each-and-Every Drop}
of The White Lightning From It ;;-}} ~ RHF
.
.

Why not short the center conductor to ground?

On 02/16/2011 12:53 AM, RHF wrote:


Ever used this?

http://www.phillystran.com/136.htm

On Feb 16, 3:48*am, RHF wrote:
On Feb 15, 5:18*pm, Joe from Kokomo wrote:

On 2/14/2011 9:01 PM, RHF wrote:

-where-as-these-
Low-cost Plastic Egg Insulators in a Bag of 10
only Cost around 60 Cents a piece.

Well, you really don't want egg insulators for this application --
that's not what they are designed for.

Their intended use is for guy wires, to break them up into non-resonant
lengths for towers that will be used to support a transmitting antenna.
Furthermore, if the egg insulator should happen to break, the sections
of guy wire will still be looped together, still providing mechanical
integrity.

- The insulator you should be talking about is
- the classic plastic or glass ribbed insulator.

. . . Consider the Alternatives . . .http://www.globalsecurity.org/milita...rmy/fm/23-10/F...
-dream-on-dave- dream-on-

JfK : As Dave pointed out I am a 'wacker' and I am
really really 'Wackie for Egg Insulators ;;-}} ~ RHFhttp://www.winradio.com/home/sw-antenna1.gif

ok Ok OK You Can Have A Nice Big Dog Bone )http://www.theaudioguru.com/product_...15118_zoom.jpg

Unless you are into Ridges {Ruffles}http://www.ssejim.co.uk/insulatornewscalebig.jpg

These two are smaller {compact} and more practical
* Alpha Delta End 'CIN' Insulatorhttp://www.dxengineering.com/ShowRelatedProd.asp?PartNo=ALP-DELTA-CIN
* Budwig HQ-2 End Insulatorshttp://www.universal-radio.com/catalog/antsup/3412.html

NEXT : Let's Talk About Un-Adulterated 100% 'Oxygen Free'
Pure Copper Antenna Wire )

-ps- I am All Antenna Anal* ;;-}} ~ RHF
*-per-Dave
*.
*.

Maybe Dave can shed some light on his mysterious ****** antenna ... or
is it Wankel ?