Transistor linear amplifier for QRP rigs

On this page you will find:

• BLA-1000
• BLA-300+
• HLA-150Plus / HLA-150V-Plus / HLA-300V-Plus
• Ameritron 500W Transistor PA

Somewhen more power is required, e.g. at times of declining sun spot activity. The PA show here is ideally suited for QRP rigs like FT-817, IC-703, K2, SG-2020 etc.

BLA-1000: 1000W Transistor amplifier for shortwave with built-in power supply

BLA-1000

Powerful transistor amplifier with up to 1000W output power. The BLA-1000 amplifier uses two MRF-157 transistor in a push/pull configuration with a supply voltage of 48 V. This results in a very good linearity and wide band capacity. The amplifier is useable from 1.5 to 55MHz, with a constant output power over all bands. The amplification is approx. 10dB (factor 10), i.e. for full output a transceiver with 100W TX power is required.

The major benefits of a transistor amplifier are of course the immediate readiness of the amp after switching it on, and the operation without tuning. This enables a very fast band switching. A precise detection of the TX frequency automatically selects the correct band filter. Several protection circuits turn off the amplifier in case of an error, for example at high SWR or high temperature. Error conditions are signaled through LEDs and the LC display on the front panel. Three large, temperature controlled fans reduce the noise level of the BLA-1000. The fans are mounted on a very large aluminium heat sink which transports the heat to the outside. This enables long transmissiosn at full power.

Operating the BLA-1000 amplifier is very easy. Just connect the transceiver, antenna and a PTT line ang go! Operation by HF vox is also possible. The LC display on the front panel shows all relevant information: Input- and output power, SWR, temperature, ALC level, current band, antenna output and much more. Two large analog instruments show other informations like supply voltage and current, power etc. All required information is presented so that it can be checked very quickly and easily.

The BLA-1000 amplifier offers two antenna outputs. Which one to use is either selected manually or automatically. For automatic operation the user can program which antenna should be active on which band, for example 160, 80 and 40m on antenna 1, and 20 to 10m on antenna 2. The amp then switches automatically between the antennas.

All in all the BLA-1000 offers high and constant output power over all amateur bands on shortwave and 6m, very simple operation without tuning. Whether you want to talk at leisure and with a solid signal, or you want to have the fast band switching for contest operation - the BLA-1000 offers all.

Technical Data

BLA-350: 300W Transistor Amp for HF with built in power supply

BLA-350

In contrast to many small amplifier for 12V operations, the BLA-350 is an amplifier for your station desk. It covers all HF bands from 1.5 to 30MHz and all modes (SSB, CW, AM, FM) and is well suited for QRP transceivers like FT-817, IC-703 etc., but also to get more power from 100W class transceivers, which can then be operated with a lower output power.

Manally switched low pass filters care for a good suppression of harmonics. Of course the amplifier does not need and heat-up time, and except for then band selection no tuning is required. The max. output power is 300W, with a max. allowed input power of 14W with the input attenuator switched on. An LC Display shows various operating parameters.

The amplifier BLA-350 has an ALC output and a PTT input for transceiver connection, but can also be operated by HF vox. The coaxial connectors are SO-239 sockets (PL sockets). The built-in power supply is suitable for use with voltages from 200 to 250V AC. Multiple protection circuits support trouble free operation: automatic switch-off at too high SWR or too high temperature.

Additional technical data

HLA-150Plus / HLA-150V-Plus / HLA-300V-Plus

HLA-150-Plus

HLA-150V-Plus

HLA-300V-Plus

Shortwave Power Amplifiers 150/300Watt
Compact and handy linear power amplifiers for all HF bands from 1.8 to 30MHz, with approx. 150 or 300W output power. These amplifiers work real linear amplifiers and not as a C class device, as many simple CB type amps do. A special feature the amplifiers have a six-way output low-pass filter, which is switched automatically by micro processor. Additionally this filter can be switched manually (e.g. when receiving).

The relative output power is shown on a bar graph on the front panel. The amplifiers have a protection circuit against high SWR. Transmit/Receive switching can be done either be HF Vox or a PTT cable. The controls on the front panel allow a selection of the Vox hold time, additionally a 3dB input attenuator can be selected, which reduces the amplification by about 50%.

Connectors: IN/OUT 2x PL, PTT: cinch socket, active low.
The model HLA-150V-Plus has two temperature controlled fans, good for continous operation. The model HLA-300V-Plus has these fans as a standard feature. On high frequencies the output power is slightly reduced, the model HLA-300V-Plus reaches approx. 250W.

Ameritron 500W Transistor PA

Compact solid state amplifier for 12V supply, suitable for mobile/expedition operations. Output power 500W PEP, 400 CW. No tuning required, just switch on and go. Electronic protection against high SWR and over temperature. Power consumption about 80A peak at 14V, separate supply lines 4A for control electronics. Temperature controlled fan, transistors used: 4x 2SC2879. Weight only 3.5kg, size 9 x 22 x 38cm.

Cinch (RCA) cables for PTT and ALC, please see Cables and accessories.