Portable VHF/UHF whip antennas and their SWR

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Portable Antennas for 2 m and 70 cm

SWR of vertical HT antennas for VHF and UHF

Did you ever wonder why the antenna of your handheld transceiver (HT) works so bad in comparison to an antenna on the roof? No, it is not just the position. The antenna which came with your HT is probably just crap - sort of a badly matched dummy load. Instead of providing a proper antenna, the transceiver's output power is increased to several watts, but most of this power is lost and simply empties the battery.

Measurement results
The following table shows the VSWR of several types of antennas as displayed by an SWR analyzer MFJ-269. To have a realistic counterpoise the antenna can work against, a handheld transceiver Albrecht RL-402 was used as ground and a ferrite at the antenna side of the coax to avoid standing waves on the cable (see diagram). In addition to the SWR on 145 und 435 MHz it was also checked on which VHF/UHF frequencies an antenna has its minimum SWR. So here we go:

Type of antenna	Length incl. plug	SWR on 145 MHz	SWR on 435 MHz	VHF: Min. SWR@MHz	UHF: Min. SWR@MHz
Kenwood TH-F7E	16 cm	7	2.0	1.4 @ 165	1.8 @ 461
Baofeng UV-3R	21 cm	3.0	2.2	3.0 @ 145	2,0 @ 440
Baofeng UV-5R	17 cm	1.1	1.3	1.1 @ 145	1.0 @ 428
Diamond SRH519	21 cm	1.2	1.6	1.2 @ 145	1.6 @ 435
Comet SMA-24	44 cm	1.4	2.5	1.3 @ 146	1.7 @ 415
L/4 for 2 m	52 cm	1.7	1.7	1.7 @ 145	1.7 @ 435
L/4 for 70 cm	17 cm	(>20)	1.5	(>20)	1.5 @ 445

For instance, an SWR of 3.0 means that the reflected power is 25 %. SWRs below this are tolerable values. However, the results are not quite stable since they are influenced by the antenna environment and by touching the antenna foot with a hand. - By the way, the 70-cm L/4 was the rubber duck antenna which came with the Albrecht RL-402 while the 2-m L/4 was a selfmade whip.

NOTE: Antenna types may be subject to change. For instance, Baofeng has been delivering different antennas for the same type of transceiver. The values shown here may also vary with the measurement setup and its surroundings.

Conclusion
The results are rather disenchanting. With the standard rubber duck antenna, a remarkable part of the battery capacity is wasted for reflected power which simply warms the PA transistors:

Of the commericially built antennas, only the UV-5R's and the SRH519 showed the best results.
The resonance frequency of the Kenwood stock antenna is far outside the 2-m amateur band.
Thus the Kenwood antenna is more or less unusable on 2 m; most power is reflected instead of radiated.
The Comet SMA-24 does a good job on 2 m and is only a bit below the Kenwood antenna on 70 cm.
A self-made 1/4-wavelength whip for 2 m nearly equals the Comet SMA-24 on 2 m and is even better on 70 cm.
A simple 1/4 wavelength whip for 70 cm outperforms all others on this band, though it is unusable on 2 m.

Alternatives
A significant and simple enhancement for quarter-wave whips on 2 m is to let a 20-inch wire hang down from the outer contact of the HT's antenna jack as a tuned radial.

A half-wave whip antenna gives excellent results if its high impedance is transformed down to 50 Ohms using an L-C match; it does not need a ground for good radiation. Unfortunately its length of 40 inches for 2 m is not very handy, and it also cannot be used as a dual-band antenna.