Ham Radio Project

We all knew RESISTANCE was FUTILE

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You’re welcome. Double check everything, all component values and eyeball it hard. If it has field effect junctions etc use proper ESD protocols during assembly. Don’t drop semiconductors on hard floors; some types can pull enough G’s to cause internal damage.

Complete!
Unfortunately I haven’t scavenged an old power supply to turn it on yet. I should have an update with it powered up next week. It takes 9 - 16 volts but I’m hoping to find something in the 15V range as the output power scales with voltage. It already is low power at 5W max so I want to try to get to the upper end of that available power. If need be, they also sell amplifier kits I could use but my interest lies in finding the maximum distance I can reach with minimum power.

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That looks so appealing! What are you gonna do with it if I may ask? Very nice build.

Hi Locutus, I’m also a radio amateur and I’ve also got that kit which is still in the box! Wonder what band you went for? I’m guessing 20m by the toroid windings. Mine is 80m but I might change that as I’m very restricted for antenna space……:frowning: Probably 40, 30 or 20. Although I do have a Ten Tec QRP rig that I built years ago on 40m. https://www.qrz.com/db/G0ILO

Yep, 20m. I don’t have a ton of antenna space at the moment. I thought it would be easy to scavenge a power supply and power it up this week but I tossed them all a while back. I’m going to see if I can grab one this weekend and hopefully I’ll have a powered up pic to show off next week.

Yeah fair enough. It is a well made kit and as I’m sure you know and many have had success on first power-up! No releasing of that magic smoke! Simple bit of alignment and away you go. Where are you, what’s your call?

KD8SLY currently /4 in Virginia.

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I found an old wall wart that says it’s 12v. I went to check polarity with a meter but it says the output was only 5v. I’ve heard of them being over voltage without load but not under. Is this broken or is there something I’m not catching?

I’ve seen half burn up powersupplies. Does the voltage exactly equal 5V? Does it drop under a load?

It bounces around a bit. It could be the el cheapo meter but I haven’t had such problems before. I haven’t put it under load yet. I just paused and went to bed since it was the wee hours.

They’re not expensive so I might just throw it out unless someone has some simple solution I haven’t thought of.

It is definitely a DC supply? Some of these wall warts are AC out, not many but some.

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Yep. It was pulled from someone else’s old stash of electronics bound for the trash. Probably just no good.

Yeah probably not worth the faff. Also you’ll need something a bit beefier anyway for the QCX in TX. I think it draws around 700mA or so.

Good quality wall wart will output the rated voltage at no load. I’ve seen plenty of cheaper wall warts that output a higher voltage - and sometimes quite a lot higher. But I’ve only seen one that output like half a volt as a “voltage probe” sort of thing: as soon as I connected any load to it, it jumped to the correct voltage. Not sure why that particular device did that, and it looked like it was by design, but it was unusual enough that I ended up not using it.