HF amplifier with MFR101

In 2018, NXP introduced new MRF101 and MRF300 power transistors to the market. They are designed for medium and high power levels in the radio frequency range, where the offer is not so rich. Why are they extremely interesting to the amateur radio community? – First of all – they are cheap thanks to the […]

90th Anniversary of the Polish Amateur Radio Union

On February 22-24, 1930, the congress and the first general meeting of the Polish Amateur Radio Union took place in Warsaw. In 2020, we proudly celebrate the 90th anniversary of this event.             Tomek SP5CCC has released for the purpose of celebrating this event a number of historical photos from […]


The SDR Active Learning Module  ADALM PLUTO from Analog Devices is used by many OM’s for working satellite QO-100. This is due to the attractive price and the excellent SSB-Modulation. No additional up- or down-converter are needed. Nevertheless some optimizations are possible. Installation in an aluminium housing avoiding radio frequency radiation Reducing frequency drift by […]

HackRF with PortaPack – Educational SDR Transceiver for 1 MHz to 6 GHz band

Chinese manufacturers have recently specialized in providing interesting and cheap radio toys, which are clones of open-source projects. An example, next to the recently popular NanoVNA analyzer, is the HackRF micro-transceiver offered with the PortaPack panel, which allows you to conduct various radio experiments. HackRF is a SDR (Software Defined Radio) module that contains transceiver […]

RF level meters with AD8318

It is not necessary to justify how important a radio signal meter is for a radioamateur, especially when entering the frequency ranges above 1 GHz. There are inexpensive meters available on the market (EXAMPLE), but you can do better by yourself 😉 using an inexpensive module with the Analog Device AD8318 IC. The schematic is […]

Properties of the horizontal dipole above the ground

The radiation pattern in the vertical plane perpendicular to a horizontal dipole over perfectly conducting ground is given by the equation: where α is the angle to the horizon (the radiation characteristics in the facade perpendicular to the axis of the dipole), and h is the height above ground in electrical degrees (where 360 electrical […]

Mosley MINI-32-A antenna test

Mosley MINI-32-A antenna test: assembly, failure, repair, measurements and start of HF5L/p in IARU SSB R1 Fieldday 2019 contest Field work, e.g. FieldDay contests – is a great opportunity to check in practice the suitability, strength and equipment parameters. We have made some test for the Mosley MINI-32-A antenna. Why did we choose this antenna? […]

HF5L/p in IARU SSB R1 Fieldday contest 2019

On the 7/8 September weekend, the HF5L team took part in the Fieldday SSB contest organized by DARC. This time in the preparations and the contest took part (in alphabetical order of call signs): Ewa SP5-1593, Andrzej SP5DDF, Mirek SP5GNI, Sławek SP5ICS, Marek SP5ISZ, Marek SP5IXS, Zbyszek SP5JSZ and Maciek SP5LCS. The place of installation […]

ADALM-PLUTO development kit for (not only) Es’hail-2 satellite

Adalm-Pluto (Analog Device) SDR radio starter kit was received for experiments by courtesy of Michał Trzaskowski from Richardson RFPD. This device gives completely new possibilities when it comes to cooperation with the first geostationary amateur satellite Es’hail-2. To name a few: thanks to the large bandwidth of the receiver (up to 6 MHz) it is […]

ICOM IC-705 SDR – A new toy for trips

Icom has presented at HamFair, taking place at the Ariake international exhibition center on the artificial island Odaiba in Tokyo from August 31 – September 1, 2019, a new compact portable QRP IC-705 transceiver, working with the use of SDR technology. Main Features: TX Bands: HF, 50 MHz, 144 MHz, 430 MHz plus 70 MHz […]