Home |
Search |
Today's Posts |
|
#1
![]() |
|||
|
|||
![]()
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. |
#2
![]() |
|||
|
|||
![]()
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 |
#3
![]() |
|||
|
|||
![]()
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 |
#4
![]() |
|||
|
|||
![]()
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. |
#5
![]() |
|||
|
|||
![]()
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 |
#6
![]() |
|||
|
|||
![]() "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) |
#7
![]() |
|||
|
|||
![]()
On May 31, 8:55*pm, "Wayne" wrote:
"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) Hi Bill, I just now ran into one of your earlier posts regarding insomnia. I have some important info for you, which I'll email to you if you'll give me your email address in a email to me, which is . Walt |
#8
![]() |
|||
|
|||
![]()
On May 31, 10:13*pm, walt wrote:
On May 31, 8:55*pm, "Wayne" wrote: "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) Hi Bill, I just now ran into one of your earlier posts regarding insomnia. I have some important info for you, which I'll email to you if you'll give me your email address in a email to me, which is . Walt Darn, Bill, I don't know why this forum deletes part of an email delivered in the text of a msg. The word preceding the @ is walt. Walt |
#9
![]() |
|||
|
|||
![]()
On Mon, 31 May 2010 , walt wrote:
I just now ran into one of your earlier posts regarding insomnia. I have some important info for you, which I'll email to you if you'll give me your email address in a email to me, which is . Walt Darn, Bill, I don't know why this forum deletes part of an email delivered in the text of a msg. The word preceding the @ is walt. Walt This is not a forum -- this is a newsgroup on usenet. If you wouldn't use the google group kludge to attempt access into usenet, you would not see such additional kludginess in your postings. And, your postings are more apt to be seen by folks that don't killfile googlegrooper postings outright due to all the spam that flows in from that seweer. |
#10
![]() |
|||
|
|||
![]()
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 |
Reply |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Mercer Electronics Tuning and Level Indicators, &c. | Homebrew | |||
BC95XLT display indicators: 25/50/75? | Scanner | |||
Understanding The Technical Market Indicators | Swap | |||
Tuning Twinlead Fed G5RV | Antenna | |||
Any 780 Users: "Channel Activity Indicators" Not Appearing: Why ? | Scanner |