Shortwave Preamplifier

Why do we need a shortwave preamplifier?

In advertising folders of many modern transceivers you'll find the criterion named Interceptpoint. In high-end transceivers it is settled in the range of +30 to +40 dBm. Because levels on shortwave at most bands are very generous, a good noise figure is dispensed; typically the value is in the range of about 20 dB

With a preamplifier you can indeed improve the noise figure, however, in our device great value was placed not only on the high bands, but also on the low bands.

The reason for the problem is often based on the use of "big" antennas, which, due to interference signals especially on the 160m band, do not allow to receive very much. Here you can almost hear the grass grow, using a preamplifier together with little selective Loops!


Remote supplying switch

The respective inputs and outputs are equipped with "small" wave barriers for optimal filtering.


Measuring of noise figure and frequency response


frequency range:

1 – 30 MHz ( .... 54 MHz)


+ 20 dB (on 6m +18dB)

Input matching:

> 22 dB (SWR better than 1,2)

1dB compression point:

24 dBm (about 300mW !!!)

Output Intercept Point (OIP):

> + 40dBm

Noise figure:


Supply voltage:

12...13V DC, about 60mA, using a remote power switch

Connectors Output:

N-Receptable or BNC

Connectors Input:

N-Receptable, BNC or two screws M4 (please select with your order)


Prices for the complete built preamplifier:

Version 1:
without remote supply switch, supply via isolating capacitor:
86,- €
Version 2:
for use with remote supply switch; (delivered in water proof housing(IP67) ):
96,- €
remote supply switch
(necessary with preamplifier version 2 !)
68,- €