Author Archives: m0spn

Hermes Lite 2 SDR Transceiver

Posted on January 8, 2020 by m0spn

The Hermes-Lite is a low-cost direct down/up conversion software defined amateur radio HF transceiver based on a broadband modem chip and the Hermes SDR project. It is entirely open source and open hardware, including the tools used for design and fabrication files. Over … Continue reading →

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QRP FT8 Operating Tips

Posted on January 21, 2019 by m0spn

A few tips on making the most out of FT8, especially when operating QRP. Listen on odds and evens *before* selecting a TX frequency. Just because you can’t hear anyone on the receive cycle doesn’t mean you’re not colliding with … Continue reading →

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OH3SPN FT8 Activity

Posted on January 18, 2019 by m0spn

I’m now active from Tampere, Finland using the call OH3SPN, primarily FT8 on 30/20/17m due to antenna restrictions; FT817 (typically 2.5W out), G4ZLP MinoProSC interface, indoor SPX-100 antenna or short wire connected to LDG Z100 Plus. I’m very happy to report … Continue reading →

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CQ DE OH/M0SPN

Posted on April 23, 2018 by m0spn

As of April 2018 I’m now located in Tampere, Finland, Locator: KP11UL.  You may see my call appearing in various logs with an OH prefix whilst I’m awaiting my official Finnish callsign. I’m currently maintaining both (M0SPN and OH/M0SPN) callsign … Continue reading →

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Over Voltage Protection

Posted on October 24, 2016 by m0spn

I recently re-homed several cheap 13.8V linear PSUs from rallies, ranging from 3 to 10A. My intention is to power smaller items of equipment; TNCs, FT817s and similar. However, after inspection it became apparent that all lacked any form over over … Continue reading →

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Hybrid (LSD) NiMH Batteries Compared

Posted on July 13, 2016 by m0spn

Receiving a set of NiCad batteries as a 10 year old (for use in a ‘Knight Rider’ RC car – how awesome was that?!) started a lifelong obsession with rechargeable cells.  My interest in batteries started even earlier than this, after being given … Continue reading →

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Chord DM01 vs Samson Q7

Posted on June 5, 2016 by m0spn

I’ve been very happy with my cheap dynamic mic (a Chord DM01) and have received many complementary reports on my audio.  However, having recently been asked to co-present a podcast I needed to confirm the mic was up to the job; … Continue reading →

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Adventures with Software Defined Radio

Posted on May 29, 2016 by m0spn

Some time ago I purchased an RTL ‘TV’ USB tuner. I was immediately impressed by the way whole chunks of the RF spectrum are visualised; tuning as simple as clicking a signal of interest plus ‘brick wall’ filters by the drag … Continue reading →

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Multi Band Slinky Doublet

Posted on April 11, 2016 by m0spn

Designing an HF antenna for Swindon Makerspace presented several challenges:- Routing coax from Makerspace to the roof is potentially tricky High external vertical antennas would require lightning protection No convenient external earths available Counterpoises impractical due to size Large horizontal … Continue reading →

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Introduction to Packet (ax.25)

Posted on January 10, 2016 by m0spn

When starting out with packet I found it difficult to find my way.  Several resources exist online but all seem to assume some basic level of understanding, which I clearly lacked.  I have to admit here, I’m still new to … Continue reading →

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