I just got my technician’s license and picked up a dual-band portable transceiver as my first radio. The stock antenna (rubber duck) is 4.75 inches and the one everyone recommends is a Nogoya NA-701 at about 7 inches. Using 1/4 and 3/4 wavelength calculations for 2m and 70cm bands, I calculated that an antenna around 19 inches would be the best for a dual-band antenna.
Now I know the actual antenna in a rubber duck is longer than the length of the duck but they are still notorious for being inefficient. So tell me why I should not look for (or make) a 18.5 - 20" whip antenna for my radio. Would the SWR ratio be to high? Is it just the inconvienence? Am I going to get RF burns or cancer on my brain?
congrats on the license.
radios used to have telescoping whips. they got broke easily.
the rubber antennas are because of durability, a hand held radio gets a lot of abuse. the antenna is a compromise in terms of what works and what breaks easily and puts people’s eyes out.
antennas can be made out of flat flexible strap. some people make their own.
But besides the inconvience is there a problem with a 19" antenna on a handie-talkie radio?
The antenna will transmit and receive fine. Your only problems will be the physical inconvenience of such a long antenna.
I think it depends upon your definition of portable. If you are just planning on going to the park, sit in a chair and use your radio the long antenna works very nicely. If you are hiking and have your radio hung from your belt the long antenna can be a bit of a pain.
The rubber ducky antenna is a helical coil - its radiation is normal (at 90 degrees) to the axis of the coil. That design allows a physically shorter design and is more robust than a whip (1/4 or 3/4 wavelength) without being noticeably worse performance for general purposes.
For most uses of a handheld, I’d recommend sticking with a rubber duck.
people might carry two antennas; a rubber duck that is left on until you are at a spot where it is safe and easy to use the whip antenna.
I was at Sanford Stadium a couple of months ago for an event and net control had trouble picking me up on my HT w/rubber duck. Couldn’t be 100 yards away.
I switched to another HT with the Diamond 519 on it, and all was clear.
I’ve made it a point to put one on all my HTs. Not too long, not too fra-gee-lay, and good performance.
I am lucky to have an HRO in town so I can pick and choose in the store.
This was interesting…11/17/02. We ran some field tests today using a whip antenna (standard) and a ducky antenna (well-known brand) mounted on equivalent Futaba transmitters using the same RF module. Measurements were made using a calibrated HP spectrum analyzer as the calibrated receiver. The receiving antenna was a 50 ohm resistor with no directivity or gain (a “monopole”). The distance between the transmitter and the receiving antenna was about 60 feet.
Ducky v. Whip Field Test
I’m picking this was a remote control transmitter. The frequency is not stated. Take the results with a grain of salt because many other assumptions for the test are not stated.
As an experiment I cut up some wire hangers. Touching them to the antenna input gives me the same reception as the stock antenna. I’m thinking of taking some SMA coax, cutting it to 19 1/4" and stripping off the outer conductor to see how it works out.
You can improve the efficiency of the duck by getting 2 or 3 strands of 19 1/4 inch lengths of stranded wire and wedge them under the collar ofhe antenna connector (ground side). This will give you a better ground plane to work off of, It works!
a pigtail? I was thinking of doing that after test out my whip idea.
Good luck and congrats on your ticket. Enjoy experimenting and 73!
If you’re reaching the stations you want, leave the rig alone. If not, try a better designed ‘duck’ antenna. If you’re mobile (in a car) or fixed, look at antennas that match your needs.
When I was active (still hold the license, just haven’t put RF out in a while) I had a Radio Shack 2M hand held that was fine when held in the hand at an event, but had dreadful range while in the car. I set up a mobile 5/8 wave antenna, power, and lapel mic station in the car and could hit most of the local repeaters while driving. If I needed more, I could have put in an amplifier.
Remember min QRP, and you can always add gain as needed. A large antenna while mobile defeats the purpose of the tiny HT sets of today.
73
-Butler
people can and do spend lifetimes antenniating.
