Knuckles from aeroelectric.com as well as Bob Archer have very good write ups/ instructions on how to build a good NAV antenna. Archer breaks down very specific way on how to create or build a Balun without using the ferrite toroids
Steve Glover Sent from my electronic leash. > On Jun 27, 2016, at 17:59, Paul-Visk via KRnet <krnet at list.krnet.org> > wrote: > > > > I've got one of those as well. Put the response public. I'm sure other > people care too. > > > > > > Ray_pilot > > New Orleans > > > > > > Ok, here is one of the responses I got off net. > > Name has been removed to protect his smartness. > > Paul, > Receiving ONLY antennas do not need a RF choke, which is what those > things really do when installed. They are used on transmitting coax to > keep reflected RF energy (standing waves) from feeding back down the > coax into the transmitter and usually ruining the output > transistor(s). Sort of like an electronic check valve. > > RST engineering is still in business, and they sell kits of stuff to > make antennas - which included's 20 ferrite toroids. Check it out at > > http://www.rst-engr.com/ > > I don't know what the diameter of RG-400 is, so if you can tell me I > would appreciate it. > > Have a good 4th weekend > xxxxxxxxxxx > > > Thanks for the response. > The RG-400 diameter is .200" > What you said is my understanding. But on RST front page they have a > picture of a VHF Nav antana. It looks like it has toroids. This is were I'm > confused > > Paul - > > Right you are - I just looked and sure enough, there seem to be toroids > in that picture. Now I'm not sure whether he used the wrong picture or > the wrong description, or whether he really does use toroids on > receiving antennas. I can see no reason to have them . . . but read on. > > That pictured antenna is a dipole, and I have used dipoles with no balun > in ham radio - and believe me, they receive fine for VOI > > CE reception. Whether or not a NAV signal is that much different I do > not know, or whether there is something about it that would make a > difference. I don't think so, but could sure be wrong. One thing I > have noticed about NAV antennas (OMNI?) on planes is that they are vee > shaped, usually pointing the open end of the vee toward the front of the > plane, but sometimes toward the rear. Maybe that makes a difference as > well so there are not blank spots in receiving NAV signals. > > I guess I should not really have commented without absolutely being > positive about the toroids on NAV antennas, but for what it's worth, it > is true that for other uses RECEIVING antennas do not need a balun or RF > choke to function well. > > Could you experiment on the ground with a temporary setup to prove the > proper reception, or would it have to be done in the air to be able to > receive a signal where you are ? I don't have a nav receiver and > indicator here to test with, or I would. As I learned many, many years > ago with ham radio, experimenting in that field is as much fun and pain > as doing it with airplanes. :-) > > If you find out what the answer to the toroid question is, please let me > know sometime. I can always learn something new. > > Thanks for the coax diameter info. That helps me. > > xxxxxxxxx > _______________________________________________ > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org > please see other KRnet info at http://www.krnet.org/info.html > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change > options
