Hi all,

So I've finally started building the tuner, and have reached the very first test. Well, I think it's failed, but I'm not sure... The values I'm getting for the regulators are 3.21V and 7.04V, which seem a little low to me. The caps are in the correct direction, I've checked for shorts and solder bridges, the power and ground wires are connected to the right holes. Just to make sure, I went back, and reformed connections. I'm stumped. When I check the voltage to the middle pins of the regulators, I get +12V.

Oh, when going through the checklist, a couple of the ICs had different numbers. I got KA258, rather than an LM258N, and a DS1489AN, rather than an MAX1489E. Are those interchangeable, or should I be giving pca a holler?

Thanks for any suggestions,

got KA258, rather than an LM258N, and a DS1489AN, rather than an MAX1489E

They're interchangeable - different manufacturers of the same thing. Might differ in some very small details; but if Patrick included them, I'm confident that differences, if any, are small enough not to matter.

/Michael

That's what I figured, but since I was posting the other problem, I figured I'd ask and make sure.

Argh... hope someone can answer the other question, now, so I can finish this thing off.

Thanks,

Atthis stage there aren't very many components on the board, so verifying you got orientations etc right shouldn't be hard. What Patrick warns about is the ferrite core, L1, and mistaking a nearby via for the proper hole... Triple check that one...

/Michael

At this stage there aren't very many components on the board, so verifying you got orientations etc right shouldn't be hard.

Yeah, that's why I'm flummoxed. Everything looks perfect, including L1. The only components that I don't see nice clean soldering on the bottom (and the hole filled nicely with solder to the top side of the board) are the three caps, since they're sitting flush with the PCB. I think I'll try raising those caps to give a bit of breathing room... maybe one of those joins isn't done well, or maybe there's a bit of excess solder that flowed through the holes under the caps, making a bridge.

Oh, wait... I'm a doofus. It's not my soldering skills that are the problem, it's my multimeter skills that are lacking. When I check the regulators with black on ground, and red on the regulator pins, I get the right values. When I was checking last night, I had the black lead on the +12V.

I must have been high on solder fumes. Yep, that's it...

Forging ahead...

Been there done that; not with Patricks kit, but a long time ago... After that I try to hook up the black lead to a solid ground somewhere - frequently straight at the power supply.

Good catch!

Good luck with the rest of the assembly!

/Michael

Woot! I'm done, and listening to the radio! I had to make a few minor deviations, from pca's instructions, though. I didn't do a good job on wiring the antenna to the lower PCB, and the inner core ended up touching the RFGND hole. The VN02s on the lower PCB also didn't stick up over the top PCB, and slipped under to rest on the leads on the underside of the top board. Then I ended up scraping a bit of insulation from the shielded two core wire while trying to shove it through that stupid hole. A bit of electrical tape fixed all three.

Uhh.... okay.... forgot to uplug the soldering iron... gotta go before the cats get on the table...

Thanks to pca for providing the tuner kit. It was a very enjoyable project.

It could be that your multimeter is not reading right - I had to recalibrate mine against my osciloscope when I saw the same problem building my first tuner kit. Regulators can actually deliver up to 10% over or undervoltage. I would be expecting 4.2 - 4.6 V for a 5V rail. 3 odd Volts is a bit low - check your meter calibration.