Topband: Vacuum variable capacitors

2013-10-22 Thread D. S. Coleman
GD All: This winter, my shack will have a new heat and light source, thanks to the warm glow of vintage 3-500Z's on Topband. :-) The downside is that now my variable capacitors in the the omega match of my folded monopole will not be up to that kind of abuse. I need to replace those old cheese

Re: Topband: Tree losses....

2013-08-06 Thread D. S. Coleman
Gentlemen: I wanted to weigh-in on the discussion of the impact of tree losses on transmitting antenna performance. Of course I have no quantitative data, but experience is suggestive of potentially significant losses. I used to live in Grayson County, Virginia, on a completely wooded hilltop.

Re: Topband: Tree losses....

2013-08-06 Thread D. S. Coleman
Hi Doug , Like so many things related to antenna installations, side by side comparisons are usually impossible. Without the ability to do meaningful measurements, it is also unlikely that one can capture all the unknowns that can add up to a large effect. I could do only relative field strength

Topband: Magnetic loops

2012-04-12 Thread D. S. Coleman
All: I can comment on my experiences with a magnetic loop, as I have one, along with three one-wavelength beverages, and a pennant terminated loop. Each of those antennas, at one time or another, proves its worth as a receiving antenna at my station. In terms of signal to noise ratio, the

Re: Topband: how to hear through static crashes?

2012-03-28 Thread D. S. Coleman
All: A comment on active noise cancelling headsets. The Heil Quiet Phone Pro is a very different animal than the Bose headsets. I have a Heil QPP and on a scale of 5 it gets a zero. Mine oscillated right out of the box and was returned to Heil for repair, but then had a high amplitude noise

Topband: Challenges adventure of radio

2011-02-23 Thread D. S. Coleman
In response to Trey, KJ4FDV, and his excellent comments: I was delighted that Trey spoke to us on the personal challenges of doing radio in this age of easy global digital communications. The adventure of radio that is as old as radio itself and part of the reason that so many of us have devoted