Sirio Car and Truck VHF Mobile Antenna
When selecting a Sirio VHF mobile antenna, the frequency range, electrical design, connector type, SWR, power handling and mechanical dimensions should be considered together. The category includes 1/4 lambda, 5/8 lambda and 2 x 5/8 lambda models. Documented versions include DV and UHF-male (PL-259) connectors, tuning by cutting the radiator, 50 Ohm impedance, omnidirectional radiation, linear vertical polarization, stainless steel radiators, spring-loaded and tiltable constructions, as well as versions supplied with RG-58 coaxial cable. Read more...
• Type: 1/4λ
• Frequency range: tunable 108-550 MHz
• Impedance: 50Ω
• Radiation (H-plane): 360° omnidirectional
• Polarization: linear vertical
• Gain: 0 dB ref. to a λ /4 whip
• Bandwidth @ SWR ≤2: 5.2 MHz @ 108MHz
• SWR @ res. freq.: 1.8 @ 108MHz
• Max. Power (CW) @ 30°C: 100 Watts
• This article refers to antenna rod only. The antenna base is not part of this article.
• Type: 1/4λ
• Frequency range: tunable 108-550 MHz
• Impedance: 50Ω
• Radiation (H-plane): 360° omnidirectional
• Polarization: linear vertical
• Gain: 0 dB ref. to a λ /4 whip
• Bandwidth @ SWR ≤2: ≥ 11 MHz @ 108 MHz
• SWR @ res. freq.: ≤ 1.4@ 108 MHz
• Max. Power (CW) @ 30°C: 100 Watts
• Connector: UHF-male (PL 259)
• This article refers to antenna rod only. The antenna base is not part of this article.
• Type: 1/4λ
• Frequency range: tunable 108-550 MHz
• Impedance: 50Ω
• Radiation (H-plane): 360° omnidirectional
• Polarization: linear vertical
• Gain: 0 dB ref. to a λ /4 whip
• Bandwidth @ SWR ≤2: see diagram
• SWR @ res. freq.: see diagram
• Max. Power (CW) @ 30°C: 100 Watts
• This article refers to antenna rod only. The antenna base is not part of this article.
• Type: 1/4λ
• Frequency range: tunable 108-480 MHz
• Impedance: 50Ω
• Radiation (H-plane): 360° omnidirectional
• Polarization: linear vertical
• Gain: 0 dB ref. to a λ /4 whip
• Bandwidth @ SWR ≤2: ≥ 11.5 MHz @ 108 MHz
• SWR @ res. freq.: ≤ 1.5 @ 108 MHz
• Max. Power (CW) @ 30°C: 100 Watts
• Connector: UHF-male (PL 259)
• This article refers to antenna rod only. The antenna base is not part of this article.
• Type: 1/4λ
• Frequency range: tunable 55-550 MHz
• Impedance: 50Ω
• Radiation (H-plane): 360° omnidirectional
• Polarization: linear vertical
• Gain: 0 dB ref. to a λ /4 whip
• Bandwidth @ SWR ≤2: 6.4 @ 55 MHz
• SWR @ res. freq.: ≤1.3 @ 55 MHz
• Max. Power (CW) @ 30°C: 100 Watts
• Cable: 5m RG-58
• Type: 5/8λ
• Frequency range: tunable 136-174 MHz
• Impedance: 50Ω
• Radiation (H-plane): 360° omnidirectional
• Polarization: linear vertical
• Gain: 4.15 dBi (1.5 dB ref. to a λ /4 whip)
• Bandwidth @ SWR ≤2: ≥ 6.7 MHz @ 136 MHz
• SWR @ res. freq.: ≤ 1.2
• Max. Power (CW) @ 30°C: 250 Watts
• Grounding protection: All metal part are DC-grounded, the inner conductor shows a DC-short
• Connector: UHF-male (PL 259)
• Type: 5/8λ
• Frequency range: tunable 139.3-175 MHz
• Impedance: 50Ω
• Radiation (H-plane): 360° omnidirectional
• Polarization: linear vertical
• Gain: 1.5 dB ref. to a λ /4 whip
• Bandwidth @ SWR ≤2: ≥ 6.6 MHz @ 139.3 MHz
• SWR @ res. freq.: ≤ 1.2 @ 139.3 MHz
• Max. Power (CW) @ 30°C: 150 Watts
• Grounding protection: All metal part are DC-grounded, the inner conductor shows a DC-short
• Connector: UHF-male (PL 259)
Special gross price: 36.97€ (Net price: 29.11€)
• Type: C-loaded
• Frequency range: 137-157 MHZ @ SWR ≤2
• Impedance: 50Ω
• Radiation (H-plane): 360° omnidirectional
• Polarization: linear vertical
• Gain: 2 dB ref. to a λ /4 whip
• Max. Power (CW) @ 30°C: 150 Watts
• Grounding protection: All metal part are DC-grounded, the inner conductor shows a DC-short
• Connector: UHF-male (PL 259)
Special gross price: 45.12€ (Net price: 35.52€)
• Type: 2x5/8 λ radialless
• Frequency: 143-147 MHz
• Gain: 6.5 dB
• Power: 300 Watts
• Impedance: 50 Ohms
• VSWR : 1.5:1 (nominal)
• Length: 2.43m
• Weight: 530 g
• Connector: UHF-male
• 90° Tilting system
Sirio VHF mobile antenna: frequency, design and connection
Which frequency range should you consider when choosing a Sirio VHF antenna?
The documented frequency ranges of the wider-range tunable SMA and MGA antenna whips vary by model and include 55-550 MHz, 108-480 MHz and 108-550 MHz. Among models related to the 2 m VHF band, the HP-S 136-174 covers 136-174 MHz, the HP 2000 C covers 137-157 MHz and the ZN-22C covers 143-147 MHz. The appropriate model should always be selected according to the required operating frequency.
1/4, 5/8 and 2 x 5/8 lambda mobile VHF antenna designs
Electrical design of Sirio VHF radio antennas
The SMA and MGA ranges include 1/4 lambda models, the HP-S 136-174 and HP 140-175 use a 5/8 lambda design, while the ZN-22C uses a 2 x 5/8 lambda collinear system. The HP-S 136-174 is specified with 4.15 dBi gain and 200 W maximum power, while the ZN-22C is specified with 6.5 dB gain and 300 W maximum power. The processed model specifications include 50 Ohm impedance, omnidirectional radiation and linear vertical polarization.
How is a Sirio VHF mobile antenna tuned?
Tuning a 144 MHz antenna using a cutting chart
The wide-frequency-range SMA and MGA whips can be tuned by cutting the radiator to the length specified for the required frequency. The related instructions specify the use of a cutting chart together with fine adjustment using an SWR meter. The HP-S 136-174 also requires adjustment of the stainless steel radiator length. Proper mounting and SWR verification are part of the documented tuning procedure.
DV and PL-259 antenna connections
Which antenna mount is required for a Sirio mobile VHF antenna?
The SMA 108-550 DV and MGA 108-550 DV use DV connections, while several SMA, MGA and HP versions use UHF-male (PL-259) connectors. The HP-S 136-174 uses a UHF-male (PL-259) connector with a gold-plated centre contact and PTFE insulator. Documented mounting options include magnetic and drilled installations. The MAG 125 PL is specified with 3.6 m RG-58 cable and a PL-259 plug.
What do SWR, bandwidth and power specifications indicate?
Comparing Sirio VHF antennas by technical specifications
The SMA 108-550 DV has an SWR of up to 1.8 at 108 MHz and a bandwidth of at least 5.2 MHz. The MGA 108-550 DV is specified at the same frequency with an SWR of up to 1.8 and a bandwidth of at least 6.3 MHz. The MGA 55-550 S has an SWR of up to 1.3 at 55 MHz. The HP-S 136-174 has an SWR of up to 1.2 at resonance, while the ZN-22C is also specified with an SWR of up to 1.2. Documented maximum power ratings vary by model and include 100 W, 150 W, 200 W and 300 W.
Stainless steel, spring-loaded and tiltable antenna designs
How do Sirio 2 m antenna mechanical designs differ?
The documented constructions include stainless steel, chrome-plated brass, nylon, ABS and PTFE. Some MGA versions use a spring-loaded structure, while the HP-S 136-174 is equipped with a stainless steel spring system. The HP 140-175, HP 2000 C and ZN-22C have tiltable designs; the documentation specifies a 90-degree tilting capability for these models. The ZN-22C instructions do not recommend magnetic-mount installation.
Sirio VHF mobile antenna advantages and limitations
Mobile VHF antenna selection criteria
- Pro: several 1/4 lambda SMA and MGA antennas can be tuned across a wide frequency range by cutting the radiator.
- Pro: DV and UHF-male (PL-259) connections, as well as spring-loaded and tiltable models, are available.
- Con: cut-to-frequency models require correct radiator length adjustment and SWR verification.
- Con: connector type, mounting method and permitted installation method vary by model.
Frequently asked questions about Sirio VHF mobile antennas
What should be checked before choosing a VHF mobile antenna?
- What impedance do the documented models use?
The processed technical specifications state 50 Ohm impedance. - Are Sirio antennas available for use around 144 MHz?
Yes. The HP-S 136-174, HP 140-175, HP 2000 C and ZN-22C frequency ranges cover parts of the 2 m VHF band. - Which connector types are available?
DV and UHF-male (PL-259) connector versions are documented. - Which model uses a 2 x 5/8 lambda design?
The ZN-22C is a 2 x 5/8 lambda collinear antenna.
Summary: selecting a Sirio VHF mobile antenna
Sirio mobile VHF antenna by frequency and mounting type
Sirio VHF mobile antenna selection should start with the required frequency, followed by the 1/4, 5/8 or 2 x 5/8 lambda design, DV or PL-259 connection, SWR, power handling and mechanical construction. We recommend checking the correct antenna mount, coaxial cable, antenna length and documented tuning procedure together with the selected model.