Mast Preamplifier for VHF / UHF / SHF

On another page of our webshop we offer a special mast pre-amplifier for ADS-B on 1090MHz (secondary IFF Radar on aircraft).

mast Pre-Amplifier

To successfully participate on VHF, you need a good receiver. These modes aren't called 'weak signal modes' without a reason... No matter if you do SSB via tropo conditions, EME or meteor scatter with modern digital modulation techniques - an excellent pre-amplifier, located close to the antenna, is indispensable. It helps to overcome the cable losses of long feed lines and improves the noise figure of the overall system.

The following criteria are important when selecting a mast pre-amplifiers:

  • Low Noise Figure
  • Good large signal handling capabilities
  • Low insertion loss
  • Adjustable amplification
  • Easy installation
  • Reliable Rx/Tx switching (by Vox or PTT)
  • DC feed over coaxial cable or separate line
  • Solid, weatherproof enclosure

We offer mast pre-amplifiers from two manufacturers: SSB Electronic (Iserlohn, Germany) and by SHF-Elektronik (Darmstadt, Germany). Both are well renowned german manufacturers with high quality standards

SSB-Electronic offers the 'Super-Amp' series of monoband mast pre-amplifiers for bands from 6m to 13cm, as well as a dual band pre-amp for 2m/70cm plus a wide band pre-amp for scanners. The preamps can be used with vox switching at reduced power or with PTT switching a high power. Hi quality helix filters suppress unwanted interference. The power supply is done over the coaxial cable or directly with a separate line. When using high power the manufacturer recommends the use of a sequencer.

SHF-Elektronik manufactures a large selection of pre-amplifiers for mast mount, for bands from 6m to 13cm, as wel las wideband models, models with two selectable antenna inputs and a 'Mini' series with an exceptionally favorable price/performance ratio. The amplifiers can handle large signal inputs very well and use stae-of-the-art semiconductors like MES-FETs and similar components, Tx/Rx switching is possible by Vox or PTT keying. The amps are equipped with helix or discrete filters for best selectivity.

Mast Receive Pre-Amplifier for 2m

Vorverstaerker MVV 144-VOX MVV 144-VOX
Vorverstaerker MVV 144 / 2 MVV 144 / 2
Vorverstaerker MINI-2 MINI-2
Vorverstaerker SP-200 SP-200

The pre-amps are simply inserted into the coaxial feed line. The power supply is either done over the coaxial cable or via a separate line. Most recent transceivers offer a supply voltage on their coaxial VHF/UHF connectors, so no external Bias-T (DC injector) is required. If required we offer a large selection of DC-injectors with or without sequencer, see below.

Most amplifiers can also be supplied with a separate DC cable. Please note that the cable should be protected with ferrites against high induction voltages.

The amplifiers do have a built-in HF vox, which allows automatic and reliable operation at standard power levels. For higher power levels a separate PTT keying line must be used. Thiscan be done directly from the PTT line of the transceiver, or by means of a separate sequencer. Most important for a pre-amplifier is the adequate gain at a good (high) 3. order intercept point (IP), this is necessary for a good large signal handling capability. Most amplifers have an adjustable gain level, this protects the receiver against overload while sufficiently compensating for cable losses.

With the larger models, the transmit/receive switching is done with real coaxial-relays, the 'Mini' series by SHF-Elektronik uses print relays. Most amplifiers (except Mini-2) are installed in two enclosures: on the inside a metal case shielding against RF, on the outside a weather proof UV resistant plastic box. A metal clamp for mast installation is included in shipment.

The pre-amp should be located as close to the antenna as possible to keep the cable (and the cable losses) as low as possible. The connecting cable to the antenna should be of high quality.

Model SHF MVV 144/2 supports two antenna connectors, which can be switched with an additional signal voltage. This enables the use of the pre amp for example with a horizontal yagi and a vertical omni directional antenna. For switching an additional switching signal is required, which is connected to a 4pin connector on the pre-amp. The required connector is included. The same connector could also carry the supply voltage, alternatively the supply can be done over coaxial cable.

The 2m/144MHz band is certainly the most used VHF band, regardless if used for tropo DX, EME, meteo scatter or FM. Here a good pre-amp is certainly most useful. At several occasions contest take place and the band is densely populated with very strong signals. This requires a pre-amp with good large signal handling capabilities.

Without a power supply all SHF pre-amps (MVV-xxx models) automatically switch to 'pass-through'. This prevents any damages to the amp when the power fails.

Technical Data 144MHz (2m) Mast Pre-Amplifier
Model MVV 144-VOX MVV 144 / 2 MINI 2 SP-200
Frequency Range 144-146 MHz
Noise Figure typ. 0,6 - 0,9 0,6 - 0,9 0,6 - 1,0 0,5 dB
Gain typ. 10 - 20 [1] dB
Max. Power (VOX) 350 (SSB) / 200 (FM) 150 (SSB) / 50 (FM) 100 (SSB) Watt
Max. Power
with Sequencer
750 (SSB) / 250 (FM) 750 (SSB) / 500 (FM) Watt
Insertion Loss (TX) 0,3 0,3 < 0,5 0,04 dB
Operating Voltage 13,5 13,5 13,5 12 - 14 V
Current c. 50 50 50 250 mA
DC-Feed via a separate cable or over coax
Max. Mast diameter 56 58 mm
Connections N N N N
Number of antennas 1 2 selectable
antenna inputs
1 1
Order No. 26101 26102 26103 26100

[1] Adjustable gain, to adjust the enclosure must be opened.

Order No.
26101 MVV 144-VOX Mast Pre-Amplifier 144MHz 189.00 € Buy now
26102 MVV 144 / 2 Mast Pre-Amplifier, Antenna Switch 144MHz 209.00 € Buy now
26103 MINI-2 Mast Pre-Amplifier 144MHz 119.00 € Buy now
26100 SP-200 Mast Pre-Amplifier 144MHz 299.00 € Buy now
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Mast Receive Pre-Amplifier for 70cm

Vorverstaerker MVV 432-VOX MVV 432-VOX
Vorverstaerker MVV 432 / 2 MVV 432 / 2
Vorverstaerker MINI-70 MINI-70
Vorverstaerker SP-70 SP-70

To operate a pre-amp on 70cm, the same basic principles apply - see above at 2m: insert into coaxial line, power supply over coax or separate cable, keying by vox or PTT line, with or without sequencer.

The 70cm/432MHz band is less used for SSB than 2m, but much more for FM. On the other hand the cable attenuation is much higher. An adjustable amplification is not strictly required because strong signals are not as prevalent as on VHF.

Without a power supply all SHF pre-amps (MVV-xxx models) automatically switch to 'pass-through'. This prevents any damages to the amp when the power fails.

Technical Data 432MHz (70cm) Mast Preamp
##modell MVV 432 VOX MVV 432 / 2 MINI-70 SP-70
Frequency Range 430-440 MHz
Noise Figure typ. 0,8 - 1,2 0,8 - 1,2 0,7 - 1,0 0,7 dB
Gain typ. typ. 22, max. 26 typ. 22, max. 26 10 - 25 [1] 12 - 22 [1] dB
Max. Power (VOX) 350 (SSB) / 200 (FM) 350 (SSB) / 200 (FM) 150 (SSB)/ 75 (FM) 50 (FM) Watt
Max. Power Sequencer 500 (SSB) / 250 (FM) 150 (SSB)/ 75 (FM) 500 (SSB) / 300 (FM) Watt
Insertion loss TX < 0,5 < 0,5 < 0,5 0,15 dB
Operating Voltage 13,5 13,5 13,5 12 - 14 V
Current consumption 200 200 200 320 mA
Voltage Feed Separate feed line, or via coax
Mast Diameter 56 58 mm
Connetors N N N N
No. of antennas 1 2 switchable
antenna inputs
1 1
26106 26107 26108 26105

[1] Adjustable gain, to adjust the enclosure must be opened.

Order No.
26106 MVV 432-VOX mast Pre-Amplifiers 432MHz 209.00 € Buy now
26107 MVV 432 / 2 mast Pre-Amplifiers, Antenna Switch 432MHz 239.00 € Buy now
26108 MINI-70 mast Pre-Amplifiers 432MHz 119.00 € Buy now
26105 SP-70 mast Pre-Amplifiers 432MHz 319.00 € Buy now
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Mast Receive Pre-Amplifier for 6m

Vorverstaerker MVV 50 VOX MVV 50 VOX
Vorverstaerker MVV 50 / 2 MVV 50 / 2
Vorverstaerker SP-600 SP-600

To operate a pre-amp on 6m, the same basic principles apply - see above at 2m and 70cm: insert into coaxial line, power supply over coax or separate cable, keying by vox or PTT line, with or without sequencer.

Although the cable attenuation on 6m is not as high as on 2m or 70cm, the antennas are much bigger and the gain lower. This can be easiyl compensated by a pre-amplifier. The activity on 6m heavily depends on the state of the ionosphere - at times of sporadic-E propagation the band is packed and a free frequency is hard to find. At other times the band is much more quiet. The pre-amp should be able to handle the strong signals without any problems.

Without a power supply all SHF pre-amps (MVV-xxx models) automatically switch to 'pass-through'. This prevents any damages to the amp when the power fails.

Technical Data 50MHz (6m) Mast Pre-Amplifier
Model MVV 50-VOX MVV 50 / 2 SP-600
Frequency Range 50-54 50-52 50-52 MHz
Noise Figure typ. 0,6 - 0,9 0,6 - 0,9 0,4 dB
Gain typ. 10 - 22 [1] 10 - 22 [1] 10 - 20 [1] dB
Max. Power (VOX) 250 (SSB) / 200 (FM) 250 (SSB) / 200 (FM) 100 (SSB) Watt
Max. Power with sequencer 750 (SSB) / 250 (FM) 750 (SSB) / 500 (FM) Watt
Insertion Loss TX 0,2 0,3 0,05 dB
Operating Voltage 13,5 13,5 12 - 14 V
Current intake ca. 100 100 260 mA
Voltage feed separate cable separate cable or via coax
Max. mast diameter 56 58 mm
Connectors N N N
Number of antennas 1 2 switchable
antenna inputs
1 1
Order No. 26119 26120 26118

[1] Adjustable gain, to adjust the enclosure must be opened.

Order No.
26119 MVV 50-VOX Mast Pre-Amplifier 50MHz 189.00 € Buy now
26120 MVV 50 / 2 Mast Pre-Amplifier,Umschalter 50MHz 169.00 € Buy now
26118 SP-600 Mast Pre-Amplifier 50MHz 299.00 € Buy now
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MVV 1296 VOX Mast pre-amps for 23cm

Pre-amp MVV 1296 VOX

The MVV 1296-VOX mast pre-amp is a low-noise antenna pre-amplifier in a double-shelled housing. The outer housing made of ABS is weatherproof and suited for mast mounting. The inner metal housing ensures a high shielding factor against unwanted irradiation and protects the components of the amplifier against harmful environmental influences effectively.

The MVV 1296-VOX has two stages to gain enough amplification for longer feed lines, also. The input stage is equipped with a low-noise microwave GaAs FET, the second stage uses a microwave IC (MMIC). The amplification is continuously adjustable, which helps to adjust to particular cable lengths. A three-circuit stripline filter provides the necessary preselection.

The MVV 1296-VOX is equipped with UHF-capable print coaxial relays, which ensure a low-attenuation carriage of the transmission power. Transmit/receive changeover is done via a PTT input or automatically by the integrated HF-VOX. With the protection circuit even in VOX operation a reliable transit/receive changeover up to 180 Watt at SSB mode is guaranteed. The operating voltage is supplied either via a separate two wire line or by remote power via coaxial cable. If the transceiver does not already provide 12V voltage for powering a pre-amp via coaxial cable, then another Bias-T (Order No. 26137.23) for remote power supply is required.

Delivery includes mast clamps.

Technical Data Receive Pre-Amplifier
MVV 1296 VOX
Frequency Range 1240-1300 MHz
Noise figure typ. 0,8-1,2 dB
Amplification typ. 22 dB
Max. Power (SSB) 180 Watt
Max. Power (FM) 100 Watt
Insertion loss < 0,5 dB
transmit-receive-switching HF-VOX or PTT-controlled
Supply voltage 13,5 V
Power requirement c. 200 mA
Mast diameter 56 mm
Connectors N
26110 229.00 € Buy now
Order No.
26110 MVV 1296 VOX Mast Pre-Amp 229.00 € Buy now
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SP-13 Mast pre-amps for 13cm


Similar design as the preamps for 2m and 70cm; these preamps always provide full amplification in order to compensate for the high cable losses at these frequency bands. The entire preamp is built upon a low-loss Teflon PCB. The SP-13 features a parallel-coupled micro-stripline filter and microwave specified print-mount relais for the trx-control.

Technical Data Receive Pre-Amplifier
SP-13
Frequency Range 2300-2400 MHz
Noise figure typ. 1,2 dB
Amplification typ. 25 dB
Max. Power (VOX) 10 Watt
Max. Power with DCW-15 (SSB) 50 Watt
Max. Power with DCW-15 (FM) 25 Watt
Insertion loss 0,5 dB
Supply voltage 12 – 14 V
Power requirement c. 120 mA
Mast diameter 58 mm
Connectors N
26115 399.00 € Buy now

[1] The amplification can be adjusted internally by a variable attenuator.

Order No.
26115 SP-13 Mast Pre-Amp 2300MHz 399.00 € Buy now
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Power Protector

Every contester is afraid of: transmit by accident into the output of the ultra-low noise preamp, any you need a new one...
No more such trouble with our power protector. To be installed between 2m TX and preamp (or downconvertor), this small magic box prevents HF power from entering your preamp. RX insertion loss is just 0.1 dB, a DC bypass is provided to allow DC supply of the preamp thru the coax. The unit itself is passive: more cabling or power supply is not required!
RF Power-Protector absorbs RF power up to 30 W FM or 50 W SSB. Furthermore it forces the TX output protection circuit to decrease the output power by ensuring a poor VSWR at the TX output.

Order No.
26165 Power Protector 99.00 € Buy now
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Sequencer with bias tee (DC injector)

Features electronic sequence controlling insuring the proper sequencing of both power amplifier and preamplifier switching. The sequencer guarantees that preamp switchover occurs before power amplifier turn on by first removing the preamplifier control voltage and then providing a relay closure the PTT line of the linear amplifier. This insures that hot switching which could damage the preamp relay contacts or destroy the GaAsFET's does not occur. Low loss bias-T's are built into the sequence controller to allow the preamp control voltage to be fed to the preamp via the coax cable. No need for additional DC cable! The preamp and the PA can be controlled separately; built-in LED's reflect the status of the sequencer. Connectors: N-type for antenna cable, for control cable D-Sub.

Order No.
26132 DCW-2004 for 6m, 2m and 70cm pre-amps 249.00 € Buy now
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BIAS-T without sequencer

Bias Tee (DC injector) to supply mast pre-amps or converters over the coax cable. HF suitable construction, low insertion loss and excellent SWR. Available with N jacks. N version useable up to 3 GHz.

Technical Data
Model FSP 144 FSP 432 FSP 1296 FSP BB DCC-5000
Frequency Range 144 - 146 430 - 440 1240 - 1300 50 - 2500 10 - 5000 MHz
Insertion loss (150 MHz) 0,2 0,3 0,8 0,8 0,1 dB
Max. Power 350 (SSB) 350 (SSB) 100 (SSB) / 40 (FM) 100 (SSB) / 40 (FM) 250 (SSB) / 100 (FM) Watt
Dimensions 52x38x27 37x37x30 37x37x30 37x37x30 37x37x30 mm
HF Connetors N
DC Connector Cinch Coaxial DC connector
Order No. 26137.2 26137.70 26137.23 26137.BB 26138

With article number 26136 the DC connector is included in the shipment. All articles with cinch connector for DC need a seperately ordered connector.

Note concerning the selection of DC injectors
The manufacturer of the FSP-xx DC injectors, Siggi, DK4MM, writes:
Often the user thinks that he can cover all use cases with a FSP-BB for any and all bands. But in reality the FSP-BB should be used only for wide band pre-amps like the MVV-2000VOX and with low power levels.
Any wide band design is always a certain compromise. Especially when reaching the lower and upper frequency limits the FSP-BB has worse return losses than a narrow band FSP-xx. For receive situations and low power levels this is not a problem, but when using high power levels the narrow band DC injectors are preferrable in any case.

Order No.
26137.2 FSP 144 2m Bias-T 44.90 € Buy now
26137.70 FSP 432 70cm Bias-T 39.90 € Buy now
26137.23 FSP 1296 23cm Bias-T 39.90 € Buy now
26137.BB FSP BB Wideband Bias-T 39.90 € Buy now
42033 Cinch connector, solder 4.10 € Buy now
26138 DCC-5000 Bias-T 5GHz 59.00 € Buy now
40076.G2555 DC Cable for DCC-5000, with straight connector, other side open 2.40 € Buy now
40076.W2555 DC Cable for DCC-5000, with angled connector, other side open 2.40 € Buy now
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MVV-2000VOX Pre-Amplifier 2m/70cm/23cm


Wide band mast pre-amplifier for the amateur bands 2m, 70cm and 23cm, and with limitations also usable on 13cm. Good amplification factor of approx. 20 dB over the wide frequency range of 90 to 2000 MHz. This makes this pre-ampo also nicely suitable for broadcast listening, airband (incl. ADS-B!), DAB+ or DVB-T. When transmitting a VOX circuit detects the emitted power and switches the pre amp automatically off. But a wired PTT line can be used also. The max. allowed transmit power is 100 W SSB or 40 W FM. The insertion loss is approx. 0.5 dB at 435MHz. Connectors are N-type female, weatherproof mast mount enclosure incl. bracket for a max. mast diameter of 56mm. Power supply via coaxial cable or separate feed line.

Technical Data MVV-2000VOX
Frequency Range 90 - 2000 MHz
Noise Figure typ. ca. 2.5 dB @ 1.3 GHz MdB
Amplification ca. 20 dB
HF power 100 W SSB
40 W FM
 
Insertion Loss 0,5 dB @ 435MHz
Supply Voltage 12-14 V
Power Consumption 250 mA
max. Mast Diameter 56 mm
Order No.
26126 MVV-2000VOX Wideband Pre-Amp 2m/70cm/23cm 189.00 € Buy now
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DBA-270 Dualband pre-amplifier

DBA-270

The Dualband Mast-Preamplifier DBA-270 improves the receiving characteristics of amateur radio stations in the 2-m and 70-cm-Band. Due to the built-in Diplexer only one HF-socket for the combi-antenna and the coaxial cable has to be connected.
The maximum output power is 100 Watt. As all preamplifiers made by SSB-Electronic GmbH, the DBA-270 offers direct feeding as well as remote feeding. Direct feeding is done over a UHF socket, remote feeding the existing coaxial cable is used, as usual. You should connect a crossover network Type DCC-12.
The DBA-270 can be switched by the transceiver via the coaxial cable, if the transceiver can contrrol a mast preamplifier.

Technical Data  
Frequency Range 144-146
430-440
MHz
Noise figure typ. 0,5
0,7
MdB
Amplification 20
24
dB
HF-power 200 W SSB
100 W FM
 
Insertion loss 0,1
0,2
dB
Operation voltage 12-14 V
Current consumption 250 mA
Mast diameter 58 mm
Order No.
26125 Duoband pre-amplifier 249.00 € Buy now
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LNA-5000 Wideband pre-amplifier

Wideband mast pre-amp from 50 up to 5000 MHz with excellent large signal rejection (IP3> 30dBm) and low noise figure, suitable for many applications: Scanner, receivers or to enhance sensitivity of measuring devices. Also suitable as low power amplifier with up to 20 dBm output, amplification c. 20dB, noise figure c. 2dB, N jacks, supply voltage 10 to 20V.
Direct DC feed or DC feed over coax, weatherproof cabinet incl. mast clamp. A Bias-T is not included! A suitable Bias-T is DCC-5000 (26138).

Order No.
26180 LNA-5000 199.00 € Buy now
26138 Bias-T DCC-5000 59.00 € Buy now
40076.G2555 DC Cable for DCC-5000, with straight connector, other side open 2.40 € Buy now
40076.W2555 DC Cable for DCC-5000, with angled connector, other side open 2.40 € Buy now
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