...under perpetual construction.
These pages contains various information about several RF power amplifiers, mainly for the HF bands, that I have built and characterized.
Most of the measurement were done with the automated system described in the automated IMD measurements page, so a standard set of data is usually shown:
Here is a list of the amplifiers characterized so far:
Measurements on an experimental 20 W HF PA for the HF bands using inexpensive modern RF devices.
Measurements on the QRP Project PA-2008, a 5 W amplifier for the HF bands.
Measurements on a wideband 5 watt amplifier, designed by DL2EWN.
Measurements on a wideband 1 watt amplifier, designed by DL2EWN.
A small power amplifier for the HF and VHF bands using a PD85004 LDMOS in class A.
Another small power amplifier for the HF band using two PD85004 LDMOS in push-pull (class AB).
A Class-A simple QRP power amplifier covering the HF and the 50 MHz band, designed by Jim Veatch, WA2EUJ.
These drivers were intended to drive an HF PA for the Hermes-Lite but could of course be used for others low-power PAs. They cover the HF bands and have an output power of about 20 dBm.
All circuit use an ubiquitous 2N2222A (or its SMD version PZT2222A) and draw about 40 mA at 12 V.
A classical resistive-feedback amplifier with 10 dB gain, 33 mW (15 dBm) output at 1 dB of compression. With a two-tone input, the output is 9 mW per tone for an IM3 of -30 dBc.
Another classic, a lossless-feedback scheme by Norton; 9 dB gain, 200 mW (23 dBm) output at 1 dB of compression. With a two-tone input, the output is 61 mW per tone for an IM3 of -30 dBc.
Another resistive-feedback amplifier, 10 dB gain, 100 mW (20 dBm) output at 1 dB of compression. With a two-tone input, the output is 27 mW per tone for an IM3 of -30 dBc.
A resistive- and transformer-feedback topology by Rohde, 11 dB gain, 160 mW (22 dBm) output at 1 dB of compression. With a two-tone input, the output is 40 mW per tone for an IM3 of -30 dBc.
Similar to the driver #3 but with higher gain (14 dB), 180 mW (22.7 dBm) output at 1 dB of compression. With a two-tone input, an IM3 of -30 dBc is reached at 50 mW per tone,
Another variation of the classic resistive-feedback amplifier, with 15.5 dB of gain and 180 mW (22.7 dBm) output at 1 dB of compression. With a two-tone input, the output is 50 mW per tone for an IM3 of -30 dBc.
This circuit has ben built in two variants, one with a 2N2222A and the other with the more modern 2SC5551A, which gives a higher bandwidth (with otherwise similar performances).
The final stage only of the Softrock Ensemble RXTX, using a couple of cheap BS170.