开云体育

I've been bench testing (ok, kitchen table) my newly constructed ATU-100, kitted by RA0SMS.

I was comparing the measured inductance with that shown on the 1602 LCD by connect my DE-5000 across the RF input and output, whilst in the simple test mode. Although the LCD counts up normally from 0 to 8.53 uH, my DE-5000 shows some significant anomalies.

When increasing inductance step by step, at both 2.20 and 4.50 uH, as shown on the LCD, the inductance falls back to minimum inductance on my DE-5000 LCR meter. It's not until 6.70 uH on the LCD meter that inductance climbs to 8.53 as designed.

I thought perhaps it was a cold solder joint, but I've actually checked the voltages on the relays, and relays are not energizing when appropriate. Logically, because I can read both minimum and maximum required inductances on my DE-5000, one distinct possibility that comes to mind is there is a programming error.

I'm thinking of making a table to indicate the energized state for each relay relative to the inductance shown on the LCD. I have version 3 of the firmware, ATU-100 EXT with 7 inductors. Before I do so, has anyone else noticed this sort of issue?

Tnx in advance de Russ, va3rr

Well, that was short-lived. Who knew 2N7002 mosfets don't like to be accidentally shorted and will release the magical smoke... lol and hi hi.

Not to worry - I have mosfets on order. I do think there is something off with the programming on my 16F1938. I'm thinking of ordering a pickit 3 clone, so I can try my hand at reprogramming the wee beastie...

Russ,
Sorry to hear about you Moffett.

On the inductor issue. I have a feeling you might be also looking at the capacitive reactance when the processor is just telling you what capacitor or capacitors it is using.

I have have found my build tuner to be better or as good as the one that comes with my Flex 6400.
Also, I did fine some bad solder connections on the one built tuner I received from Russia.
Ron/W4DNQ

Ron - I think it was a combination of cold solder joints on the 16F1938 and perhaps a solder bridge.

In the Fast Test mode, all of my relays were activated, so that's why I'm thinking a solder bridge. But in Simple Test mode, the relays for L6 and L7 were only operating under certain circumstances.

A bit of solder wick and a hot soldering iron has fixed everything. Just waiting on my new MOSFET and some standoffs to finish this project...

Excellent!