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This board was created to enable the use of the latest LDMOS-FET's devices.

With this board, can be used with different types of LDMOS transistors.

For example - BLF178, BLF178XR, BLF188, BLF188XR, BLF578, BLF578XR, MRF6VP11KH, MRFE6VP61K25HR6.

Technical characteristics for BLF188XR.

This 1400 W extremely rugged LDMOS power transistor for broadcast and industrial applications in the HF to 600 MHz band.

The BLF188XR and BLF188XRS are capable of withstanding a load mismatch corresponding to VSWR > 65:1.

In a range from 2 to 30MHz (test signal CW) BLF188XR, Pout is 1270W.

FEATURES of the module with LDMOS BLF188XR

Model: PA Unit BLF188XR - ReV. 2017
Frequency range: 1.8-50MHz
RF power output: 1000W typical, 1200W max. 1.8-35MHz; 700W 50MHz.
Modes Supported: FM, CW, SSB and others.
RF power input: 7W typical, 10W max.
Supply: 50-54VDC / 30-32A
Board dimensions: 163 x 120 mm

BIAS adjusted in accordance with temperature.

Vbias: 12V for keying the amplifier

For better IMD, use negative feedback circuit.

Additional elements for AFC correction.

Input VSWR is optimized with attenuator on PA input.

The heat sink and a copper heat spreader (not supplied) have to be larger than 200mm x 140mm and proper fan cooling must be provided too.

You can use BLF188XRS.

If you want to get 1000W Pout, you need very low input power, about 3-5W Pin. In this order, you need to be very carefully on first power on.

On 160m, 80m, 40m, 30m, 12m, 10m can be Pout up to 1200W. On 50MHz can be Pout up to 700W. On 70MHz can be Pout up to 500W.

To increase the gain at frequencies of 30-70 MHz is possible by changing the values of capacitors C21, C11, C48.

A full technical documents with all instructions on CD (in parcel) is provided with the board.

An application of these boards for summing up the power, you can watch such a monster in Youtube videos. The author of the Mr BBI channel. The video is called - 4 Pill ldmos blf188xr, lets run it, lets look inside