Category Archives: Lab / Testing

MFJ-4117 Bias Tee – 0.06dB loss

Posted on 2020-04-15 by James

In order to remotely power my SG-230 Smartuner which will (temporarily) live in my attic to “tune” a large vertical loop antenna, I opted to use a bias-T to inject DC power onto the coax. Bias tees are passive components … Continue reading →

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FM Transmitter analysis

Posted on 2014-03-16 by James

It has been far too long since my last update and so I decided to do a cursory analysis of an FM radio transmitter (the kind you would use to listen to your MP3 player in a vehicle which lacks … Continue reading →

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CHU & WWV vs Rigol DSA815-TG

Posted on 2013-10-03 by James

The other night I had a conversation with Ernie (VE3EJJ) about spectrum analyzers, etc. and he asked if I had tried tuning in CHU or WWV on the spec. an. yet. Sheepishly I said “no,” having never thought to undertake … Continue reading →

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Characterizing a Bencher YA-1 low-pass (TVI) filter

Posted on 2013-09-03 by James

Some time ago I bought a couple of low-pass / TVI filters from a ham-fest. It is mandatory to ensure that you are not producing out-of-band or otherwise harmful interference and so having such a filter assists in ensuring that … Continue reading →

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