---------------------------------------------------------- Avionics-List Digest Archive --- Total Messages Posted Mon 07/14/14: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 10:38 AM - Re: King KX155 weak VOR reception (D L Josephson) 2. 02:41 PM - Re: King KX155 weak VOR reception (Jimmyb) ________________________________ Message 1 _____________________________________ Time: 10:38:22 AM PST US From: D L Josephson Subject: Avionics-List: Re: King KX155 weak VOR reception On 7/13/14 11:58 PM, Avionics-List Digest Server wrote: > * > > > 1. Do you think it's likely that the open multiplexer port could be causing my > issues? It's possible, but not too likely to cause the severity of symptoms you describe. You could eliminate the nav splitter by taking it out of the circuit, connecting the antenna lead to one VOR or the GS only, and seeing if the problem remains. > > 2. How likely is it that the old RG58 cable could be causing my issues? Not likely, unless it has gotten mashed somewhere. More likely that a connector or the termination between the antenna and the cable has failed. I have 50 year old RG-58 that's still fine. There's no practical difference between old RG-58 and LMR400 in your application -- there will be more loss in the additional coax connectors than there is difference in attenuation. You could try an old vee dipole bolted on to the underside of the tail as a test. > > 3. Should I bite the bullet and buy an antenna analyzer such as the rigexpert AA > 600? Since you can't get to the antenna, no. An "antenna analyzer" will not tell you whether you have an effective antenna, which may be very different from 50 ohms but still work fine, or an open at the end of the cable. A 50 ohm resistor at the end of tiny coax will look great but won't be a very good antenna. The best comparative test will be with a low power VOR/GS ramp tester. ________________________________ Message 2 _____________________________________ Time: 02:41:00 PM PST US Subject: Avionics-List: Re: King KX155 weak VOR reception From: "Jimmyb" Re my interest in an antenna analyzer: I've been looking at some of the newer units online (such as the Rigexpert AA-600) and it appears they have the capability of testing the coax for faults (distance to fault) while connected to the antenna. I wasn't thinking of replacing the RG58 with RG400 simply because of the RG400 is a lower loss cable, rather I wanted to use the analyzer to check the RG58 for faults. I would replace the RG58 with RG400 ONLY IF the RG58 is questionable (open, shorted, etc). This BTW may be a real possibility because the existing cable makes some pretty tight bends under the panel. Also using a tester such as the AA-600 would allow me to check the SWR of the antenna. Thoughts? -------- Jim Phoenix, AZ Read this topic online here: http://forums.matronics.com/viewtopic.php?p=426666#426666 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message avionics-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Avionics-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/avionics-list Browse Digests http://www.matronics.com/digest/avionics-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.