Hi I have made a set of coaxstubs for bandpass filter, but it is not enough attunation.. Is it normal with 20-30 db attunation ?? We had big problems during WPX SSB as LN5O we experienced that the st
attunation.. Yes. See http://audiosystemsgroup.com/Coax-Stubs.pdf This is a first draft tutorial that I'm still working on. attunate enough between 20 40 & 15m... You need to buy W2VJN's excellent bo
Rag, Sometimes it seems there is a big difference between theory and practice in dealing with solutions to inter-station interference. I am guessing you would not be as concerned if you just had a st
how long was the coax from rig to stub? Do you have multiple stubs? and if so, how far apart are they? _______________________________________________ _______________________________________________
Hi all is mounted into a small painting box. Different bands have multiple stubs to null to different bands. It is placed about 10-15 ft from the rigs, but I dont have cable between the stubs as I ha
A lot of very useful information all in one place. Thanks Jim for a great job! Howard..K2HK HK _______________________________________________ _______________________________________________ TowerTal
Any time you believe there is a difference between theory and practice you don't know enough about one or the other. That is, you don't know ALL the theory, only part of it, and you don't know all of
Jim Bravo! VERY neatly put. Thanks Bill--W4BSG _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://l
See http://www.kv1j.com/6BPF/index.html -Rex K1HI Rex Lint Merrimack, NH --Original Message-- From: towertalk-bounces@contesting.com [mailto:towertalk-bounces@contesting.com] On Behalf
Ok, I will try to make two of them in serial. Did you use any recommended spacing between them ? 73 LA6FJA Rag --Opprinnelig melding-- Fra: leewical@lava.net [mailto:leewical@lava.net] Sendt: 30. mar
This is discussed in detail in W2VJN's book. Don't be a cheapskate -- he's done the work and published it, the work is excellent, and the price is reasonable. He deserves our support. 73, Jim K9YC __
Hi I ordered it :) let see if we can do some changes to perform better in 2 radio contesting. 73 LA6FJA Rag _______________________________________________ ___________________________________________
Along a similar note.. The stub is just a moderate Q resonator that's easy to fabricate. Why not put a lumped LC shunt trap across the feedline? Too hard to get the Q low enough? Doesn't have the nic
I've given up trying to make the lumped element argument to hams. Too hard to change belief systems. Coax stub filters are firmly entrenched ham radio folklore, regardless of whether they make engine
Jim, Great info on stubs, and very timely given that Field Day is only 2 1/2 months away. A couple of quick questions: Does a higher "Q" coax yield more attenuation, all other things being equal? I k
Yes. I know the notchwidth would be reduced, but was curious about notch depth. The reduction in width is measured from the deepest part of the notch. In general, higher Q (lower loss coax) is better
I also don't understand the seemingly single-minded fascination with coax stubs. It takes more than one stub to get the same attenuation that a properly designed lumped element filter can provide, th
Dave, Can you design a lumped element filter that can handle 1.5 KW???? ____________________________________________________________ Staples® - Weekly Ad Incredible deals at Staples! Buy 1 get 1
Certainly. Why would you think otherwise? You just need low loss components. Air wound coils would handle high power easily, but it's a bit trickier to find capacitors that handle high RF current. I
Chris, the attenuation of these stubs is limited only by the loss in the coax used to make the stub. If you think about it, you are trying to create a dead short at the frequency of the trap. A dead