Kirk's test may be kinda rough but I won't agree that it doesn't tell anything. As a matter of fact, it is in line with the experience reported by many that installing antennas inside carbon fuselage does not result in noticeable reduction in range.
Would like to hear some constructive suggestions on how to run a more reliable test to obtain more conclusive results but pls be practical. For example, I don't consider it necessary to measure the effect of carbon on the antenna pattern inside an echoless chamber. Y C Lui --- In [EMAIL PROTECTED], Simon Van Leeuwen <[EMAIL PROTECTED]> wrote: > Hi Kirk, > > If I understand you correctly you have hooked up a length of wire to an > SA I/P and introduced an external signal @ 75.5MHz. I will assume the > wire is fed throught the SA's centerfeed (+) terminal, ignoring the GND > (outer threaded structure and the SA's metal casing itself). I will also > assume that you are reading directly off the SA. > > It does not tell you anything. > > Add to this that 1dB of any type of RF measurement, is not enough to > make any decision as to whether there is actually a gain or loss in > energy. Also keep in mind that an antenna on a RX with assorted wiring > on servos etc represents a significantly different scenario than the > test you have generated. > > > BTW, do you recall the spec for the chipset used in the Vision's storage > as to how many storage or input parameter changes before the system > starts generates errors? > > > > > Kirk Hanson wrote: > > > > After the discussion of the past couple of days, I decided to do a > > quick test. > > > > I took a 24 inch piece of insulated wire and connected it to an HP > > spectrum analyzer. Nothing magic about 24 inches except that it would > > fit completely in the arrow shafts that I have. The arrow shafts are a > > Beman ICS400 and an ICS500. I don't know the lay-up in these except > > they are carbon colored and have the word carbon on them. I found an > > ambient signal at 75.5MHz and used this as the transmitter. I found > > that I had about 1db more signal with the arrow shaft over the > > antenna. Explanations might be that the arrow shaft is longer so it > > coupled in more signal, or that the arrow shaft made the antenna > > impedance closer to 50 ohms (the input impedance of the analyzer). > > > > I also tried this at 36MHz and found that the arrow shaft over the > > antenna was about the same or slightly better that the antenna alone. > > > > Any comments from the RF engineers out there? > > > > Kirk Hanson > > TPG San Diego > > > > -- > *~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~* > Simon Van Leeuwen, Calgary, Alberta > RADIUS SYSTEMS > Cogito-Ergo-Zoom > IAC25233*MAAC12835*IMAC1756*LSF5953*IMAA20209 > *~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~* > RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off.
