Steve - when I see an increase in Intermod, my mind goes away from poor grounds, and towards oxidized connectors and flaky relay contacts.
Reseat all connectors, tighten all screws, and hot-switch relay contacts till you find the offender. Tim N3QE Sent from my iPhone > On Dec 7, 2016, at 4:35 PM, VE6WZ Steve <[email protected]> wrote: > > I’m wondering what experiences are out there regarding small vertical array, > or beverage performance in the winter over frozen ground. > > The reason for this question is that over the last 2 weeks or so, my HI-z > (24’ vertical) SDR skimmer antenna at my remote QTH has shown somewhat > diminished performance and a dramatic increase in AM inter-mod byproducts on > 160. > During the somewhat hasty install of this antenna (the SDR “RBN skimmer” > antenna was not considered an important part of the station) I had some > trouble driving the ground rod for the HI-z amplifier and only ended up with > about 3’ of copper pipe driven into the ground. During this past summer and > fall the performance was good. > Winter has been here for a while. Last night it was -28 deg C. Today, that > rod is now probably sitting in a block of solid ice. (ok, not solid ice, but > the conductive dissociated ions from the native salts distributed within the > soil are now locked in ice) > > In truth I am not really concerned about this particular antenna, but I do > plan to install an 8 circle array as well as some beverages this summer and > this problem got me thinking about making sure I have a “seasonally stable” > ground system up here in the frozen north. > Some quick research points to potential frost depths ranging from 6’-8’ > depending on snow cover and soil type. Perhaps driving deeper rods could > help, but it seems to me that there will still be a seasonal change of > consequence. Literature associated with various short vertical array products > indicate that 3’-4’ rods should be adequate, but is this true in a northern > climate? > For the most part, I could care less whether the array works in the > summer…..it’s during our winter DX season that I want performance. > > Perhaps a very carefully designed and symmetrical short ground radial system > could stabilize things, but I know with phased rx vertical arrays this can be > a big problem and cause phase imbalances. Perhaps on my beverages a small > radial system at the termination would be helpful. > > I am not new to rx antennas, having built and used numerous single wire > beverages, reversible beverages and end-fire phased beverages as well as > passive and active (Hi-z) phased vertical arrays at my home QTH, but have > never “noticed” a problem. > BTW, it is possible that there is something else going on with my SDR antenna > other than a ground problem, and I will be checking that out next time I’m at > the station. However, I think I’ll still want to consider the frozen ground > impact even if there is something else going on. > > Any experiences, measurements or ideas from those living in places where it > snows a lot, you have something called a “block heater” for your car, and > when you work outside you last about 5 minutes before your hands and toes are > numb?? > > de steve ve6wz. > > > Steve Babcock > Lead Geologist, Mature > TAQA North Ltd. > D +1.403.724.5147 > M +1.403.870.0082 > 2100, 308 – 4 Avenue SW, Calgary Alberta > Canada T2P 0H7 > > > www.taqaglobal.com > TAQA is the brand name of Abu Dhabi National Energy Company PJSC > > If you no longer wish to receive email from TAQA, please click to Unsubscribe > > > > > This message contains confidential information and is intended only for the > individual named. If you are not the named addressee you should not > disseminate, distribute or copy this e-mail. Please notify the sender > immediately by e-mail if you have received this e-mail by mistake and delete > this e-mail from your system. E-mail transmission cannot be guaranteed to be > secure or error-free as information could be intercepted, corrupted, lost, > destroyed, arrive late or incomplete, or contain viruses. The sender > therefore does not accept liability for any errors or omissions in the > contents of this message, which arise as a result of e-mail transmission. If > verification is required please request a hard-copy version. > > From Babcocks iPhone > _________________ > Topband Reflector Archives - http://www.contesting.com/_topband _________________ Topband Reflector Archives - http://www.contesting.com/_topband
