Home |
Search |
Today's Posts |
#6
![]() |
|||
|
|||
![]() "Buck" wrote in message ... I want to test a couple of antenna designs and compare them to a dipole antenna. I am wondering if my idea is a good way to measure gain or loss from an antenna. Here goes: Create a place in which to install the test antenna which will be consistent. For example, 40 foot high between two power poles (no power lines etc, though.) Setup a fixed location with a Field Strength Meter (FSM) that has a fixed antenna for testing at that location. Hang a dipole (the reference antenna) and transmit a signal that can be calibrated to a fixed location on the FSM. Then hang the experimental antenna in place of the dipole. Take the measurements without changing anything from the rig. Measuring the power output required to meet the same setting on the FSM as the dipole should give me a fair idea about the gain or loss from the experimental antenna. or maybe not. What am I overlooking? Thanks Buck N4PGW -- 73 for now Buck N4PGW Put some ferrite tubes (big beads) on the coax near each antenna; this will minimize radiation off the feedlines. Also, put a 3 dB attenuator on each antenna, to stabilize the system impedance. Secure the feedlines so that they are hanging in the exact same position each time. And don't forget that 40' off the ground is not good for frequencies below about 50 MHz.If you want to dig very deep, there's an IEEE standard on antenna calibration (but it's not free). You might find an old SAE 958 (IIRC) document on antenna calibration. Ed wb6wsn |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Questions -?- Considering a 'small' Shortwave Listener's (SWLs) Antenna | Shortwave | |||
Discone antenna plans | Antenna | |||
EH Antenna Revisited | Antenna | |||
Antenna Range Testing. | General | |||
Antenna Range Testing. | General |