Dear Group, I'd like to thank all those who sent their ideas. DK7FC suggested shunting the LF tuning coil with a series resonant LC, but ON7YD said it could affect bandwidth on 160m. Stefan wondered
Hello Hartmut, Group. Good to hear from you again, Hartmut. Thank-you for the report. The beacon is on again, but there was some trouble: to use the tower on 160m the 500 kHz tuning coil (0.2 mH) is
Hi Alan, Group. Thank-you for the reply. Multiple contacts in series were considered... but the gap has to increase by orders magnitude! How much gap will I need for 50 kV? Your spiral pie story was
Hello Stefan, the formula for the capacitance of a vertical monopole with a height H (m) and a diameter d (m) is: C(pF) = 24*H/log(1.15*H/d) I got the formula from "Taschenbuch der Hochfrequenztechni
Hi Joe, Maybe you can switch a series LC circuit which is resonant at 1850 kHz parallel to the 0.2 mH coil? For example 200 pF/37uH. You must then re-adjust the 0.2mH coil a bit. Can be calculated or
Joe.. There are some 'good' rf relays at :- http://www.surplussales.com/Relays/rfopen.html Ive used the small open frame one's for some time on the HF bands may be a couple of the 6 Kv open frame in
Yes engineering wise it quite possible to produce a actuated Knife switch but , that path may be a little problematic ? I would be surprised, if say 3 of the 6Kv relays in series flashed over , as ea
I'm puzzled by the 6pf/metre rule for monoploes. It seems the capacitance of the monopole is much higher. Hi Joe, based on a resonance with 3mH @137.8kHz the antenna capacitance would be 445pF. A rat
Hello Rik, Interesting, haven't known that. What do you think applies for a 10mm diameter wire? 73, Stefan Am 12.10.2011 09:30, schrieb Rik Strobbe: I'm puzzled by the 6pf/metre rule for monoploes. I
Stefan, I had that in mind too (series LC circuit) but bandwidth might be an issue at 1.8-2.0MHz. 73, Rik ON7YD - OR7T ________________________________________ Van: [email protected]
Hi Joe, why not stick two sets of normal contacts in series....doubles the gap :-)) Alan 23:20 UTC http://www.mun.ca/cc/policies/electronic_communications_disclaimer_2011.php
Hi Joe in theory 50kV will need about an inch ....25mms but this is always a try it an see thing in my mind. I reckon it "non-linear" on you strike an arc you can increse the gap a lot before it goes
