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HT Antenna Modification For Increased
Edited and re-written from an
"Getting the Most from Your Hand-Held Transceiver"
C. Edward Harris, KE4SKY, AEC Fairfax ARES
Also see the HT performance mod by N6JSX at
the end of this article for lots more
When limited to "barefoot"
operation, with a "rubber duck", HT antennas are not very efficient
nor adequate for communications. They fail miserably as an effective
radiator due to their design! They are nothing more than an extended
dummy load acting as an antenna!
The following modification
will help you to make the most of your HT by increasing the
factory antenna's efficiency and the cost is just a piece of
FACTS ABOUT HT
The National Bureau of
Standards tests of Public Safety high band and amateur 2-meter
antennas indicate that a "rubber duck" has -5db, "negative gain"
compared to a quarter wave held at face level. In terms of effective
radiated power (ERP), this means that a 5 watt HT with rubber
duck, radiates only 1 watt. Operating an HT on your belt results in
another -20db attenuation, reducing ERP to 50 milliwatts! That's
1/20 of one watt!
UHF results are no better...
Due to the design of the
factory installed HT antenna, you are effectively missing half of
MODIFY THAT HT ANTENNA FOR BETTER
Get ready to use that scrap of wire you have in
your junk box!
inexpensive and effective method to improve a "rubber duck"
antenna is by adding an external counterpoise or "tiger tail"
thereby adding the other "half".
be noted that if your HT is under warranty, the internal
modification may void that warranty...you have been
Adding the other
You can easily build one from a
quarter-wave piece, (about 19.5" on 2m, 11.5" for 220 and 6.5" for
440), of stranded insulated wire, crimped and soldered to a battery
clip or use a small spring tension clip that will fit the BNC
antenna connector with the wire attached to it. Use a clip or other
connection that fits tightly but can be removed if needed. It must
make both a good mechanical and electrical
Another method would be to attach the end of the
wire by soldering it to a grounded portion of the circuit board
inside the HT, although this may not be practical with some models,
or any point that is at ground potential on the HT such as the
"ground" side of an external speaker/headphone jack, the BNC
connector at the antenna, or the Negative side of the battery
terminal. The preferred location is at the
factory antenna base at the BNC connector. If you have some
other type of metal antenna connector the same applies.
of the newer models don't lend themselves to internal modifications
easily. If the "rubber duck" antenna that came with the HT does not
come off, then you will have to make the connection inside the HT to
a grounded point. Extreme care must be taken to prevent shorting out
other components!!!!!! Use insulated
wire. You may have to drill a small hole in the case for the
exit point of the wire and tie a knot inside to provide strain
relief. Each installation will be different. Use your own judgment
and at your own risk!
Always reinforce the soldered
connection with heat shrink tubing or tape to resist flex and
shorting to other components if possible.
When the counterpoise,
(the other half of the antenna), is clamped to the outer collar
of the BNC connector on your HT antenna, it helps to prevent RF
from coupling with your body, so your completed HT antenna
"system" acts much like a center-fed dipole instead of an
end-fed dummy load!
built a directional antenna and did not know
In marginal conditions, extending the
counterpoise horizontally and pointing your hand to steer the
radiation pattern where you need it, produces a dramatically
stronger signal than letting it "droop" towards the ground.
Experiment with the angle of the counterpoise to get the best
results. In effect, you are creating a form of "V" type center fed
vertical dipole with a bit of gain compared to just the factory
If you want to
buy another HT antenna, rather than add the counterpoise
described in this article, then it is recommended that you shop
around. Don't be misled by the cheaper priced antennas. Buy
from a reputable dealer that will answer your questions. Try to
find an antenna with published gain figures compared to a
dipole or 1/4 wave vertical. Don't expect Yagi or similar
performance....have fun and get better performance than
The N6JSX HT
We all know OEM
(original equipment manufacture) HT rubber-ducky antennas are a
dismal compromise, at
best, facetiously called "helical-dummy-loads".There are a few ways to improve your HT'ing distance and experience. First and
foremost consider buying an after-market antenna, like the Diamond SRH77CA-SMA or RC77CA-BNC,
or make a more economical full 1/4 wave
BNC Brass Whip and add a Tail. I found my
2m Brass Whip to work well on 70cm too.
Second, is to improve the
antenna's counterpoise; an HT body is a very poor counterpoise! A
product I saw decades ago, called the
"Tiger-Tail", seemed to have been the answer to this problem but it was just too easy for HAMs to
reproduce, killing its sales. The Tail is a 1/4 wave + 5
percent counterpoise wire hung from the HT antenna connector
creating a mock 1/2 wave dipole. The trick in making an affective Tail is to
insure a good tight fit to the HT connector. I duplicated the Tail
by using ring terminals
but a problem with ring terminals are those darn BNC posts. I over
came this by filing a
small notch inside the ring to fit over one post, twist it around
the BNC barrel and slip it over the other post. See
But with the advent of HT's
going to a SMA connector the BNC post issue disappears making
this Tail a much
simpler and far easier to attach.
Notice the new notches in the rings! Cool
is a 1/4 wave +5 percent length of wire hung from the HT connector.
Thomas & Betts
SMA = 1/4
inch eye for 14-16AWG wire (blue) T&B #14RB-14X
BNC = 3/8 inch
eye for 10-12 AWG wire (yellow) T&B #10RC-38X
stranded wire is soldered to the ring.
(I do not crimp my tails
but solder the tail wire to the ring terminal.) See Table "A" in the
complete download pdf file link below for wire lengths per
The hardest part of using this
Tail is getting the wire to hang straight. 73~~~
Download the complete pdf
file here for the entire project details and
Editor note: You may need to get
an adapter to go between your exiting ht antenna and the case
connector of your ht. The type of adapter would depend on the
type connector at the case of your ht and stock antenna
bottom end. A good source of adapters and connectors can be found by
clicking the banner below!
Wired Communications has many
types of adapters and connectors at great prices!
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