Author: Razvan

MRF1K50H – new 1500W LDMOS from NXP

LDMOS technology allowed huge improvements in RF power transistors in the recent years, bringing much better performance and efficiency at a lower price point than ever before. A pair of top-of-the-line MOSFETs of the late 80’s such as the MRF157 are specified at 1.2KW with 45% effciency in AB class up to 50MHz and would set you back almost US$ 1000 even today. Compared to that, the new generation LDMOS offer more power than that at 70+% efficiency and 1/4 the cost, while they work up to 500MHz. MRF1K50H is the name of the latest and greatest LDMOS RF...

Read More

ESDR – new portable SDR HF transceiver

ESDR is a portable SDR transceiver with HF coverage that is supposed to be released in August. The ESDR features a large color display, digimode decoder/keyer, 2x USB ports and micro-SD card. The required supply voltage is 12.6V and the maximum output power is 30W. ESDR‘s large color LCD shows supply voltage, current draw, battery level and final stage temperature, are all very important parameters when working portable. Time and date are a nice addition too. ESDR‘s size and ergonomics seem to be inspired by the Elecraft KX3. Not the ideal concept for a rugged field radio, but provides...

Read More

Romania (YO) gets 60m access

Following the conclusions of the World Radiocommunications Conference 2015 regarding the 5MHz band, supported by two local Romanian amateur organisations, the Romanian authority for communications (ANCOM) is granting temporary access for radio amateurs to a channel in the 5MHz band (60 meters). The spectrum to be granted is 3kHz wide (from 5363.5kHz to 5366.5kHz) and will be made available on a secondary access basis, with no privileges. The access is temporary – it will come under review after one year, with the possibility to add a second channel. The main purpose is so that Romanian amateurs study propagation in...

Read More

Icom IC-7300 and spectrum / waterfall on the PC

Icom IC-7300 is a great feature radio, but the main complaint about it is there’s no I/Q output (or at least video output like in the IC-7000) so you can see the spectrum/waterfall display on a larger screen. Icom IC-7300 waterfall I kept telling people the Icom IC-7300 already has an internal soundcard available through the USB port and the spectrum/waterfall display is available in the Icom RS-BA1 software, also via the USB connection, so there’s no need for I/Q (which is very sensitive to zero-hertz interference and amplitude/phase mismatch). Until I saw these videos:   It seems the...

Read More

Yaesu FT-891 – new HF/50MHz transceiver ?

Yaesu FT-891 is the latest equipment the japanese manufacturer is working on. Although the details are extremely limited, it seems we are talking about a HF/50MHz mobile radio similar with the FT-857 in size. Update: Yaesu shows the FT-891 at Dayton 2016, seee the following link for more details: Yaesu FT-891 update A test report suggests the Yaesu FT-891 has 30kHz to 56MHz receive coverage, with TX being enabled in the amateur radio bands. We don’t know exactly what type of architecture is used and it may very well be possible not to share the same design with the...

Read More

3 years later

I started this blog 3 years ago, a few months after I got my first amateur radio license and about the same time I got my @YO9IRF Twitter account. Looking back, I was less active thant I wanted (about one post every two weeks, on average) so I hope to improve that in the future. I posted stuff that I’d like to remember years later (like the YO SOTA Marathon or many other SOTA activations), interesting stuff that I wanted to keep my eyes on (like the Xiegu X1M cheap QRP transceiver), I posted a few opinions of my...

Read More

Icom IC-7300 review

Icom IC-7300 is the first direct sampling SDR (software defined radio) available from one of the “big three” japanese manufacturers. This helps it bring a whole new level of performance at an accesible price point, a much more flexible configuration and a set of features only seen in top-of-the line equipment. Real-time panadapter or fully customizable filters are just the tip of the iceberg.   Sure, amateur equipment has been using for a long time various levels of digital signal processing (DSP), but usually this was done in the last part of the receive chain, where it mostly impacted...

Read More

Icom IC-7300 schematic

Icom IC-7300’s schematic just became available, and you can get it here: Icom IC-7300 Schematic diagram Not everything is revealed, the RX-ADC is still a blank rectangle although many suspect the LTC2208 is used. Enjoy...

Read More

Archives