twinlead tuning indicators
 

On Mon, 31 May 2010 15:20:03 -0700, "rb" wrote:

Memory has usual cob webs. Help clear it.......

When I feed twinlead, seems I might use a small fluorescent bulb to show how
it's doing.

Hi OM,

What you call fluorescent, I assume, must mean a small NE2 neon
indicator bulb which would be suitable to what you describe.

If a small fluorescent bulb will do this, do I just tune for
"max smoke" while holding it near the twinlead? Can't recall if a small
flourescent bulb will do this or not.

It is going to be an indication of "something."


If radiation is cancelled, not sure how it would fire.

Within close proximity (about 3 to 5 times the wire separation), you
still have a sense of each wire. Further away, there is so little
difference in distance to either of them, that they both add with
cancellation.

I vaguely remember we used to use twin lamps, wired backwards for this
purpose. One way you had SWR on one side; the other way you had SWR on
the other side. Neither light being lit meant good SWR.

This must be the cobwebs you speak of. Other than LEDs (and I think
you would have specifically said so if your indicators were these),
lamps have no sense of current direction. Example, what would happen
if you reversed the plug to your table lamp? Would it suck light?
Have you ever put in a fluorescent bulb with the wrong polarity?

73's
Richard Clark, KB7QHC

twinlead tuning indicators
 

Richard Clark wrote in
:

Example, what would happen
if you reversed the plug to your table lamp? Would it suck light?

As it is, they suck dark. Right?

https://www.msu.edu/user/dynicrai/physics/dark.htm

twinlead tuning indicators
 

Richard Clark Inscribed thus:

On Mon, 31 May 2010 15:20:03 -0700, "rb" wrote:

Memory has usual cob webs. Help clear it.......

When I feed twinlead, seems I might use a small fluorescent bulb to
show how it's doing.

Hi OM,

What you call fluorescent, I assume, must mean a small NE2 neon
indicator bulb which would be suitable to what you describe.

If a small fluorescent bulb will do this, do I just tune for
"max smoke" while holding it near the twinlead? Can't recall if a
small flourescent bulb will do this or not.

It is going to be an indication of "something."


If radiation is cancelled, not sure how it would fire.

Within close proximity (about 3 to 5 times the wire separation), you
still have a sense of each wire. Further away, there is so little
difference in distance to either of them, that they both add with
cancellation.

I vaguely remember we used to use twin lamps, wired backwards for this
purpose. One way you had SWR on one side; the other way you had
SWR on the other side. Neither light being lit meant good SWR.

This must be the cobwebs you speak of. Other than LEDs (and I think
you would have specifically said so if your indicators were these),
lamps have no sense of current direction. Example, what would happen
if you reversed the plug to your table lamp? Would it suck light?
Have you ever put in a fluorescent bulb with the wrong polarity?

73's
Richard Clark, KB7QHC

I have vague recollections of a reflectometer using diodes, lamps and
300ohm twin feeder. Maybe in an old copy of Radcom...

73's
--
Best Regards:
Baron.

twinlead tuning indicators
 

Memory has usual cob webs. Help clear it.......

When I feed twinlead, seems I might use a small fluorescent bulb to show how
it's doing. If a small fluorescent bulb will do this, do I just tune for
"max smoke" while holding it near the twinlead? Can't recall if a small
flourescent bulb will do this or not.

If radiation is cancelled, not sure how it would fire.

I vaguely remember we used to use twin lamps, wired backwards for this
purpose. One way you had SWR on one side; the other way you had SWR on
the other side. Neither light being lit meant good SWR.

twinlead tuning indicators
 

In article , "rb"
wrote:

Memory has usual cob webs. Help clear it.......

When I feed twinlead, seems I might use a small fluorescent bulb to show how
it's doing. If a small fluorescent bulb will do this, do I just tune for
"max smoke" while holding it near the twinlead? Can't recall if a small
flourescent bulb will do this or not.

If radiation is cancelled, not sure how it would fire.

I vaguely remember we used to use twin lamps, wired backwards for this
purpose. One way you had SWR on one side; the other way you had SWR on
the other side. Neither light being lit meant good SWR.

RB-

My cobwebs are probably worse than yours. As a teenager back in the
50s, I used a "Full Windom" antenna (off-center-fed-dipole) fed with 300
Ohm TV twin lead.

The SWR measurement circuit I used probably came from an ARRL
publication. It consisted of two 6 Volt dial lamps connected to each
end of a section of twin lead. I think it was two or three feet long.
The whole thing was taped to the transmission line. There was a
connection at the center of this on one side to one side of the
transmission line.

As I understood it, one lamp was supposed to glow and not the other. I
think both of mine glowed, but one was definitely brighter. Of coarse I
did not know what I was doing and had no real understanding of SWR. I
made contacts, so never worried about it!

Using a fluorescent tube, I would expect it might glow at points along
the transmission line where voltage was high and extinguish where
voltage was low. With a low SWR, there would be no high voltage points.
Or maybe no nulls?

Fred
K4DII

twinlead tuning indicators
 

When I feed twinlead, seems I might use a small fluorescent bulb to
show how it's doing.
....[snip]....

See:

"The Eyes Have It; Making S.W.R. Measurements with the Twin-Lamp"
on page 50 of the October, 1948, issue of QST.

"The 'Coax Twin-Lamp', A Simple S.W.R. Indicator for Solid Line"
on page 25 of the November, 1948, issue of QST.

"Measuring Center Impedance of Antennas with the 'Twin-Lamp" on
page 67 of the May, 1950, issue of QST.

"Old Reliable" on page 67 of the April, 1958, issue of CQ.

--W0PBV.

--
-- Myron A. Calhoun.
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
NRA Life Member & Certified Instructor for Rifle, Pistol, & Home Firearm Safety
Also Certified Instructor for the Kansas Concealed-Carry Handgun (CCH) license

twinlead tuning indicators
 

On 05/31/2010 03:20 PM, rb wrote:
Memory has usual cob webs. Help clear it.......

When I feed twinlead, seems I might use a small fluorescent bulb to show how
it's doing. If a small fluorescent bulb will do this, do I just tune for
"max smoke" while holding it near the twinlead? Can't recall if a small
flourescent bulb will do this or not.

If radiation is cancelled, not sure how it would fire.

I vaguely remember we used to use twin lamps, wired backwards for this
purpose. One way you had SWR on one side; the other way you had SWR on
the other side. Neither light being lit meant good SWR.


I can only relate an experience I had in my house in Minnesota. We had a
long hallway and I could just shuffle my feet and the fluorescent light
I was carrying lit up from the accumulation of charge. Free, well almost
free light. A guy in the S.F. bay area has a house near a radio
transmitter and his garage is pretty well lit by 4 foot tubes he has put
around.
YMMV.

twinlead tuning indicators
 

On 05/31/2010 03:39 PM, Fred McKenzie wrote:
In ,
wrote:

Memory has usual cob webs. Help clear it.......

When I feed twinlead, seems I might use a small fluorescent bulb to show how
it's doing. If a small fluorescent bulb will do this, do I just tune for
"max smoke" while holding it near the twinlead? Can't recall if a small
flourescent bulb will do this or not.

If radiation is cancelled, not sure how it would fire.

I vaguely remember we used to use twin lamps, wired backwards for this
purpose. One way you had SWR on one side; the other way you had SWR on
the other side. Neither light being lit meant good SWR.

RB-

My cobwebs are probably worse than yours. As a teenager back in the
50s, I used a "Full Windom" antenna (off-center-fed-dipole) fed with 300
Ohm TV twin lead.

The SWR measurement circuit I used probably came from an ARRL
publication. It consisted of two 6 Volt dial lamps connected to each
end of a section of twin lead. I think it was two or three feet long.
The whole thing was taped to the transmission line. There was a
connection at the center of this on one side to one side of the
transmission line.

As I understood it, one lamp was supposed to glow and not the other. I
think both of mine glowed, but one was definitely brighter. Of coarse I
did not know what I was doing and had no real understanding of SWR. I
made contacts, so never worried about it!

Try this.. I had an Ampex tube amplifier driving a high voltage
transformer and as the music danced (in my head) the patterns were
dancing to the same beat. I just drove the input of the Ampex with the
output audio line. Yes, that was in the 70's and yes we were all stoned.
I don't think that anyone else tried that combination, but it was way cool.
Bill Baka

Using a fluorescent tube, I would expect it might glow at points along
the transmission line where voltage was high and extinguish where
voltage was low. With a low SWR, there would be no high voltage points.
Or maybe no nulls?

Fred
K4DII

twinlead tuning indicators
 

On 05/31/2010 03:51 PM, Bill Baka wrote:
On 05/31/2010 03:39 PM, Fred McKenzie wrote:
In ,
wrote:

Memory has usual cob webs. Help clear it.......

When I feed twinlead, seems I might use a small fluorescent bulb to
show how
it's doing. If a small fluorescent bulb will do this, do I just tune for
"max smoke" while holding it near the twinlead? Can't recall if a small
flourescent bulb will do this or not.

If radiation is cancelled, not sure how it would fire.

I vaguely remember we used to use twin lamps, wired backwards for this
purpose. One way you had SWR on one side; the other way you had SWR on
the other side. Neither light being lit meant good SWR.

RB-

My cobwebs are probably worse than yours. As a teenager back in the
50s, I used a "Full Windom" antenna (off-center-fed-dipole) fed with 300
Ohm TV twin lead.

The SWR measurement circuit I used probably came from an ARRL
publication. It consisted of two 6 Volt dial lamps connected to each
end of a section of twin lead. I think it was two or three feet long.
The whole thing was taped to the transmission line. There was a
connection at the center of this on one side to one side of the
transmission line.

As I understood it, one lamp was supposed to glow and not the other. I
think both of mine glowed, but one was definitely brighter. Of coarse I
did not know what I was doing and had no real understanding of SWR. I
made contacts, so never worried about it!

Try this.. I had an Ampex tube amplifier driving a high voltage
transformer and as the music danced (in my head) the patterns were
dancing to the same beat. I just drove the input of the Ampex with the
output audio line. Yes, that was in the 70's and yes we were all stoned.
I don't think that anyone else tried that combination, but it was way cool.
Bill Baka

Using a fluorescent tube, I would expect it might glow at points along
the transmission line where voltage was high and extinguish where
voltage was low. With a low SWR, there would be no high voltage points.
Or maybe no nulls?

Fred
K4DII

Whatever it was it was sure pretty and tube had ripples from both ends
that we could just watch. You would almost have to see it to believe it.
Kind of like visible standing waves going the length of the tube.
I think that kind of thing would kill any new solid state amps.
Bill

twinlead tuning indicators
 

"Richard Clark" wrote in message
...
On Mon, 31 May 2010 15:20:03 -0700, "rb" wrote:

Memory has usual cob webs. Help clear it.......

When I feed twinlead, seems I might use a small fluorescent bulb to show
how
it's doing.

Hi OM,

What you call fluorescent, I assume, must mean a small NE2 neon
indicator bulb which would be suitable to what you describe.

If a small fluorescent bulb will do this, do I just tune for
"max smoke" while holding it near the twinlead? Can't recall if a small
flourescent bulb will do this or not.

It is going to be an indication of "something."


If radiation is cancelled, not sure how it would fire.

Within close proximity (about 3 to 5 times the wire separation), you
still have a sense of each wire. Further away, there is so little
difference in distance to either of them, that they both add with
cancellation.

I vaguely remember we used to use twin lamps, wired backwards for this
purpose. One way you had SWR on one side; the other way you had SWR on
the other side. Neither light being lit meant good SWR.

This must be the cobwebs you speak of. Other than LEDs (and I think
you would have specifically said so if your indicators were these),
lamps have no sense of current direction. Example, what would happen
if you reversed the plug to your table lamp? Would it suck light?
Have you ever put in a fluorescent bulb with the wrong polarity?

73's
Richard Clark, KB7QHC
-
The LEDs that suck light are normally referred to as DEDs (Dark Emitting
Diodes)