Author: Razvan

ADE-1-24 mixer

ADE-1-24 are double-balanced RF mixers that can be easily found all over eBay, Aliexpress and a few other websites. They are usually available for attractive prices and sometimes might be advertised simply as “ADE-1”. However, the manufacturer claims that ADE-1-24 is a custom version of the Mini Circuits ADE-1 mixer, built on order for a customer and not necessarily identical to the ADE-1. There are no official specs published for the ADE-1-24. All of the ones available seem to have the same manufacturing date code 628, which means they were manufactured in the 28th week of 2006. The case and...

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Amateur Radio Weekly – great newsletter

I recently discovered the Amateur Radio Weekly – a newsletter put together by Cale (K4HCK), and I was impressed. The content is wonderfully curated, it looks amazing and the overall impression is very professional.

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Yaesu FT-818 details leaked (FT-817nd replacement)

Rumors about the Yaesu FT-818 have been circulating for about 6 years and now we get to see the first details on the new portable QRP all-band all-mode transceiver from Yaesu. Finally, the replacement for the very successful Yaesu FT-817nd is about to see the light of day.

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XTRX mini-PCIe SDR for embedded, now crowdfunding

XTRX is a mini-PCIe implementation of the Lime Microsystems LMS7002M RF IC aimed at the embedded environment, done by Fairwaves. It is now available through a crowdfunding campaign. The XTRX’s main features are the integrated GPSDO (GPS Disciplined Oscillator), the compact size (just 30x51mm) and the 120MHz max RF bandwidth (!). Such a wide bandwidth generates a very large volume of data, so only a high-speed low-latency port like the PCIe can handle it. The FPGA used in conjuction with the LMS7002M is the 33k cell, low power Xilinx Artix-7 35T.     The radio specs are what you...

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Baofeng DMR6X2 – dual band DMR handheld, 7W output

Baofeng, your favorite Chinese manufacturer is at it again. Their next product is called the DMR6X2 and as you might guess, it’s a DMR radio. A handheld, VHF/UHF, Tier I & II DMR radio that has up to 7W output to be exact. You don’t need to have a really sharp eye to notice that the radio in the picture is actually an Anytone AT-D868UV; it seems like rebranding it as a Baofeng DMR6X2 might make sense, especially if this would mean adjusting the price downwards, maybe to compete with the Radioddity GD-77 and the like. Some of the...

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Yaesu FT-757GX – fixing some common faults

I recently got a Yaesu FT-757GX to use as a backup radio for the shack. The previous owner said it has no RX audio on any other modes except CW, but the TX was fine and the S-Meter was moving on all modes. This got me thinking there is just a problem with audio switching and by looking at the schematic I knew where to start. When I got the radio, opened it up and started to diagnose the known issue, I discovered many more. As I came to find out these are quite typical for the Yaesu FT-757GX,...

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Si5351 output waveforms

I finally managed to have myself some shack time this weekend and one of the curiosities I had was to check the output waveform of the Silicon Labs Si5351 I2C programmable VCXO. The chip is quite popular among homebrewers thanks to its low price, ease of use, the fact that it generates 3 independent outputs across a very wide bandwidth (8kHz to 160MHz) and that it offers lower phase noise than the cheap & cheerful AD9850/1 DDS modules.   Adafruit Si5351 module By the way, there are also some versions of the Si5351 that have 8 independent outputs instead...

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