Topband: grounding the ends of radials
but if it was done with a ground rod that's not really much of a ground for rf. It isn't there to provide a ground. It is there to intercept return rf, which flows not far below the surface. So a ground spike is a more appropriate term. Ground rods are good for safety purposes. Yes, I am assuming insulated wire laid on or near the surface. But grounding the far end of buried bare radials doesn't do any harm. A single ground rod at the base of a vertical isn't going to provide much of a ground. True. But a ring of short grounding spikes, connected together and back to the base (U.S. Army tactical grounding system), provides a reasonable alternative to a metal plate. The radial network is a non-resonant counterpoise. Sometimes, but not always. Bob VE7BS _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Signal attenuation from foliage near 160m antenna
Subject: Topband: Signal attenuation from foliage near 160m antenna This subject has been discussed here plenty of times in the past, and the consensus has always been that trees and other foliage near a 160m antenna has a negligible effect on the transmitted signal. That's what I have believed for some time. Without doubt foliage has measurable effects on the antenna when it is close to a voltage point (speaking from experience with loops), so Carl's findings make good sense. Bob VE7BS _ Topband Reflector
Re: Topband: Comparison testing
I distinctly remembered' how well a 300-foot high dipole I had worked, Very evocative quotation marks. Reminds me that the area of the brain that deals with memory also deals with creativity (imagination), and that one definition of imagination is remembering something that didn't happen.And the more often we remember, the more intensively we believe. Bob VE7BS _ Topband Reflector
Re: Topband: Ground mounted 1/2 wave
I think this thread has gone to the limit, because the argument is between emotional conviction laced with constant personal insults and science. Too bad the thread was marred by the insults and implications. There was lots to be learned even from the digressions, once one had figured out who meant what by ground mounted versus in the vicinity of ground, height of antenna versus elevation of antenna site etc. I must say most of the amateurs I know have no idea of the effect of a change of 0.1 dB (or 1 dB for that matter) and tend to think and report in terms of full S-points. Bob VE7BS ___ It is undesirable to believe a proposition when there is no ground whatsoever for supposing it is true. #8212; Bertrand Russell
Re: Topband: substandard quality F double females
I did speak to Lee at Hi-Z yesterday and he warned me about substandard quality F double females. He has had terrible problems with them. In what respect are they sub-standard? What kind of problems? There is so little that could be defective if the center conductor of the coax is the right size to fit the double-female coupler. Bob VE7BS ___ Topband reflector - topband@contesting.com
Re: Topband: Beverages 2 basic questions
Next year Im planning to try a couple of Slinky Beverages again in order to get a 2-3 wave electrical equivalent for particular paths and narrow the beamwidth to get rid of EU noise. Carl KM1H Come on Carl! You're just being provocative. Someone may take that seriously. You know very well that only the physical length matters for narrowing the lobe. Bob VE7BS ___ Topband reflector - topband@contesting.com
Re: Topband: Beverages 2 basic questions
Thank you Mike. I did not know of the velocity factor parameters when I made my practical experiments many years ago, and gave up when I ran into anti-phasing and excessive broadening of the lobe. I see now from Tom's paper that if one knows just what one is doing, a Slinky could be useful. I've been at it a long time, and I am still learning. And apologies to you, Carl. 73, Bob VE7BS - Original Message - From: Mike Waters mikew...@gmail.com To: topband topband@contesting.com Sent: Saturday, December 01, 2012 11:47 AM Subject: Re: Topband: Beverages 2 basic questions It does? http://www.w8ji.com/slinky_and_loaded_beverages.htm Maybe Tom and Carl are both in on this conspiracy. ;-) ___ Topband reflector - topband@contesting.com
Re: Topband: Inverted L SWR Jumps ???
Tom: MOST antennas are in a neither world of being neither perfectly balanced nor perfectly unbalanced. How about an inverted L longer than 1/4 wave but optimized with series capacitor? Any closer to perfect unbalanced? Bob VE7BS ___ Topband reflector - topband@contesting.com
Re: Topband: Fw: Re: Radials over a stone wall
Anyone guess what would happen if the radials going over the wall were coax shielded ? That's a VERY interesting thought. Somebody model it please. Bob VE7BS ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: QRP and Bird 43 Watt meter help
Hi Jim Many years ago at 4U1ITU I found the Bird 43 grossly underestimated the power output on 160, rather embarrassing at the temple of regulation. Bob VE7BS The 250H range is 2 to 30 mhz 160M is not quite covered but I think is ok. ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Two wire Beverage Question
Hi Herb, Niko: could be that it is too long for 40. This is just a gut reaction as I have not come up with any reason. Of course it is too long. Beverage said that when it is too long there are so many lobes (and therefore nulls) that it is 50-50 that a given direction will not be covered; that velocity factor may antiphase a given frequency at the transformer; that the extra lobes pick up more QRM/QRN; that for amateur purposes (not point-to-point) one wavelength or so is optimum; if you don't know the exact direction the signal will come from then with more wavelengths of wire you are in the lap of the gods and Murphy, so sometimes it will serve your purpose and sometimes it will not. Bob VE7BS ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: TB season
Bill and now it's over till next year? I don't know how it is in W4 and/or W2, but here in 7-land the season is not over, although if people think it is it often appears to be. For trans-Pacific paths the prop is better from May to September, especially for northern and western VK. 73 Bob VE7BS - Original Message - From: K4OWR k2...@comcast.net To: topband@contesting.com Sent: Thursday, March 15, 2012 3:55 PM Subject: Re: Topband: TB season ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Topband Digest, Vol 107, Issue 28
Hi Barry But it's taking up a lot of band width for no apparent reason. in my own humble opinion, any further discussion is a waste of cyberspace. I, for one, have not found it boring. I don't believe we now know all there is to know, and text does not take much file space. Some just tune up and work 'em and some are more interested in the why and how. 73 Bob VE7BS ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: high take-off angle
Hi Jim Twenty years or so ago NM7M wrote a program in DOS that predicted the position of the tilt in the E layer on the dark side of the terminator, more than usual refraction at that point causing a steeply downward signal as it exits the layer. Believing this, I made sure I had some antennas that responded to high angle, and they often provided better results than the high vertical loops just at that time, resulting in hundreds of early morning QSOs with VK and ZL. The band opened earlier for the lower angle response antennas, but they ceased to be better about half an hour before sunrise. It was common experience for West Coast stations to see better signals from the Pacific on Inverted Vees than on monopoles just before sunrise. I suppose if one has only one antenna, a low angle response one is better for DX, as long as it has some response at 20 or 30 degrees, but some QSOs will be missed. Bob VE7BS - Original Message - From: Jan Erik Holm sm2...@bdtv.se To: topband@contesting.com Sent: Sunday, October 16, 2011 8:15 AM Subject: Re: Topband: high take-off angle This I have NEVER seen in SM2 land, the lower angle the better. Jim SM2EKM -- ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Topband: high take-off angle
I dont understand the sudden urge or desire of some to suppress all high angle radiation from an inverted L. It is well established that even a low horizontal dipole can work amazing amounts of DX on 160 when conditions allow and having both possibilities present in the L is a benefit. Carl Hear! Hear! Especially at or near SR and SS. Bob VE7BS ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Bi-Directional Beverage Question - DXE Polarity
1. It could be a convenient accident. 2. If on purpose, the answer is probably Just in case this is useful. But then you would expect DXE to draw attention to it . 3. Useful that this has been discovered and brought to our attention. Bob VE7BS So other than phasing two Beverages, has anyone found a reason why DX Engineering does this? ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
