Icom External Keypad

In the past I’ve designed and built external keypads for triggering the REMOTE input on an Icom mic connector [1] & [2].  These both were designed to add an auto repeat feature to the in-built Icom voice keyer for older radios by monitoring the radio’s PTT state (the duration of the voice recording) then adding

144MHz 1.25Kw SSPA Amplifier

Winner in Craftsman category of the RSGB Construction Competition 2014 Waw, what a device.  The Freescale (and NXP) SSPA parts are quite incredible. The part I’ve used is the MRFE6VP61K25H, which is a 1.25Kw device with peak gain and efficiency figures of 26dB and 78% respectively at 144MHz, that means for 1Kw output the drive

BX-184 Voice Keyer

The BX-184 is a voice keyer developed by Olli DH8BQA designed to fit into the case of a Yaesu MH-31 microphone.  I used the BX-184 at the G3PYE contest station before upgrading to an FA-SM Station Manager. BX-184 Features Even though the BX-184 is designed to fit into a Yaesu mic case it’s not limited

DTMF Keypad (and more) Explanation

Wow, I just realised I created this project back in May 2008… I think the principal and technique used for the keypad is worth explaining however so I’m publishing it now. When my local repeater GB3PY started providing Echolink access my shack radio was an Icom IC-910 which does not support DTMF to control Echolink.

Mobilinkd Bluetooth TNC Auto Power on Mod

In my car I use an Icom IC-2820 which is a dual band (dual receive) mobile radio, but only ever monitor one side at a time (the other side has the volume down) and in the previous car I used that side for APRS.  Until recently I was not able to find a way to

70MHz Transverter Mk5 – Nacton

I’m a sucker for continually re-building, I’ll have you believe *improving*, my 4m transverter, the first I built in 2010.  The Nacton variant is the Mk5 iteration in as many years!  The transverter is essentially the same, 28MHz IF and > 50w output (300w peak in later versions) on 70MHz and all in the same

Hy-Gain HAM-IV Rotator Upgrade

I seem to find myself updating each and every rotator I own to have a digital readout plus a few other cool features, my latest one is converting my Hy-Gain (CDE) HAM-IV. The original HAM-IV is analogue meter based, and rather annoyingly for me in the northern hemisphere the display is configured for South Stop,

FA-SM Station Manager

Everyone needs an FA-SM Station Manager.  I got one after using a BX-184 (boxed) for a while but wanted some more features. It has these features; A voice keyer with up to 60 seconds memory in total. 4 memories are available that can have different not predefined length’ as long as the total duration does

144MHz Harris Amplifier

Modification of the Harris Amplifier is not the reason for this article, there are many documents on the web covering this [Site 1, Site 2 part1 & Site 2 part 2], I followed Mark GM4ISM’s as Mark was the source of my Harris amplifier bits. I actually purchased a Harris amplifier ‘pallet’ from Mark, this

432MHz (70cm) Masthead System (Remote RX/TX Amp)

Following on from my 23cm Masthead system I decided G3PYE needed a similar system for 70cm.  The system will mirror the 23cm version with a TX amp and a Preamp in the box, but in addition I fitted a band pass filter for 432MHz. TX Amp John G4BAO kindly donated a UHF PA which has