Brief Description: Checked Transceiver power out and SWR
A few days ago I tried to check the power out and SWR (Standing Wave Ratio or reflected power) of my new transceiver, however, things didn’t go well. The frequency range of the watt/SWR meter I borrowed was too low, so it wouldn’t work. I looked on-line to see what a good RF wattmeter would cost to buy, and the ones I used to use when I worked as an RF Design Engineer were really expensive. I did find a cheap wattmeter on Amazon ($20 shipped – see image 1) that I ordered and it arrived today. Since the transmit frequency range goes from 118 to 137 MHz I thought I’d measure the SWR every three MHz. The instructions for the transceiver say that an SWR of up to 3 to 1 is operable. My results were:
118 MHZ 1.9 to 1 ratio 121 MHz 2.1 to 1 ratio 124 MHz 2.5 to 1 ratio 127 MHz 2.6 to 1 ratio 130 MHz 2.9 to 1 ratio 133 MHz 3 to 1 ratio 136 MHz 3+ to 1 ratio
These readings were from my $20 watt/SWR meter and the $20 antenna installed as per the plans - except I installed the antenna from the pilot's side. See image 2. I think most of the frequencies I’ll be using will be between 121 and 124 MHz, so the installation should be pretty good. While I was playing around with the transceiver, I tuned in to the local airport at Manitowoc (WMTW) and heard a couple of guys talking as clear as a bell; another good sign.
