Hi David,

Will there be a complete kit of parts with smd chip already soldered?

Also, what is the maximum power for this ATU I ask because I have a Tentec Argosy which is 50W or 5W switchable

I also have a number of QCX qrp rigs 5W or less.

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I am mainly CW op so keydown would be higher than ssb average I recon.

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Cheers Mark G0NMY

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Hi Glenn

I'm guessing you may have damaged the auto and bypass switches while soldering. I did exactly that with my auto switch. I used magnet wire for the ground bus and overheated to burn off the insulation. I was able to rescue it by reheating the sunken terminal and pulling it out of the switch somewhat, though I'm on the lookout for better quality switches. Try disconnecting the wires from the switches and shorting them to ground manually.?

Your SWR and power readings are probably off due to the inferior Shottky RF-sensing diodes. Mine is also off (Ali-Express, Hisonauto). I ordered some 1N5711 diodes from Mouser. I'll have them early this week and I will post an update.

The Ali listing for my tuner claimed that it would tune down to 1 W. It seems to do that just fine using my KX3. I did not do the binocular transformer mod and programming change.

New to the group, hoping to get some advice to get my little tuner going.

What I have is the typical Aliexpress kit, preloaded with 3.2.? I ordered the version that supplies SO-239 connectors and the Auto and Bypass switches.

It went together reasonably well.? The only assembly details that might be of note are:

• the Bypass and Auto connections to the bottom of the board were tough and I may have to revisit them.? Way too small for me to do confidently with a soldering iron. I ended up using two short lengths of the wire left over from the binocular transformer, with the ends cleaned up.
• I was supplied with 8 electrolytic capacitors.? There's only space for 6, so I assume I got two extra in error.? I've seen nothing to suggest they belong somewhere else, like the bottom of the board.
• No wires for connecting the SO-239 connectors were included.? I assumed that an inch or so of unshielded wire would be OK to make the connections to the board, rather than try to convince chunks of RG58 to do the contortions.? The connectors have short ground wires to the board as well.? I didn't run a wire between the two connectors, assuming that the board would do that.
• I didn't put capacitors across the Auto and Bypass switches, something I've seen mentioned while looking for answers (none included - I'm assuming the extra electrolytic caps weren't intended for this purpose?)
• I didn't use the center out of a piece of coax cable for the binocular transformer.? What I had was solid center conductor and kept breaking when I tried to bend it to the necessary shape.? I ended up using insulated stranded wire that *just* fit through the holes on the board.

It powers up.? The display shows Power, SWR, L and C as zeros.? There's a dot to the right of the power line to signify (I understand), Auto mode.? That all looks promising, but the behavior isn't.? I'm seeing a few things that don't seem right, which may or may not be connected.? In no particular order:

• Auto and Bypass switches don't seem to do anything.
• Powering up with the switches depressed doesn't seem to do anything.
• Tune button works as I believe it should - reset with quick press, Tune with longer push.
• When I put RF to the tuner, it makes all the snapping sounds one would expect, then shows an acceptable SWR on the display.
• Power on the display is crazy-high... suggesting my 10 watts is actually over 100 watts.
• Radio shows the same high SWR as without the tuner in line... unless I set the TX power up to maybe 20 watts... then it seems that the clicking and snapping results in something the radio likes.
• The Auto dot indicator will switch to the underscore mark instead, after tuning is complete.? I can't get the dot back unless I power cycle the tuner.
• Transmitting again, on the same frequency will sometimes result in the tuner trying to find a better result.? Sometimes it does, sometimes it ends up failing and the L and C values show as 0.
• When a match is found, the SWR indicated by the tuner might be 1.15:1, but the radio is reporting 1.75:1.? In some cases, the radio reports 'off the scale' while the tuner is indicating a good match.
• On 30m, I saw a match determined, but the SWR reported by the radio continued to rise with 20 watts continuing to the antenna.? This suggests a thermal issue in an inductor perhaps?

I'm at a loss as to what to try, where to look.? I suppose it's possible that there are a few issues at play here, so maybe the first place to check is at the Bypass and Auto connections on the bottom of the board.? I can feel the anxiety building though, just thinking about putting the iron to those spots again... ;-)

I spend some time looking for a procedure to follow to troubleshoot this tuner, but found nothing.

All suggestions appreciated!

73

Brock VA7AV

Thanks David

Can you advise what the solder blob links marked as "P" and "R" are for?

I think I found the correct USB "C" connectors also, on ebay:-?


Glenn

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But e aware that many eBay cheap BNC connectors are 75 ohm, not 50 ohm types and many other eBay offers do not have the impedance specified..

Bill, VK7MX

That's correct, BAT54S protecting diodes.

All OK David.

My build is progressing, a few more toroids to wind, but waiting for the main PIC and FET drives.

Just wondering about the two SOT-23 devices near the TUNE button??? Is anything fitted there ?? EDIT?? new BOM shows BAT54S diodes.

Glenn

Hi people
The link on BNC connectors was added to BOM on Github


I never tried previuous connectors from Digikey, be carefull. The needed connectors should to have the pin pitch 6mm, other similar connectors have a different pitch.
Remember, you can use very cheap panel mounting connectors like this?

Hi, Scott
Thank you. I don't have a time to make a schematic, this tuner is not the main project for me.
If you could do that - please use Easy EDA CAD??
Unfortunatelly this Layout 6 project does not have any numerated components, so I can't to create a list.

Today I have received 16F1454 from Philippines, PIC16F18877 still on the way.

Hi, Glenn
Are you about pin 3 on the schematic ? You are right that is 4 pins connector, sorry for this missunderstanding.
Actually pin 3 just goes to short to ground when simple 3-pin jack is using and that is not weigh with work in this mode.
4-pins sockets are compartible with 3 pins Jacks,?
Put both theese Jacks close to each other and you will see how it works.
Sorry, I was sure that pin 3 is a "jack insertion detection pin" and nothing more. Actually it works exactly like this with using 3 pins mini jack.

David

If you scroll down the listing a little, you will see that there is a drawing of the pads and also two ''schematics" of the part. Both show thats its a 4 pin device.

Of course perhaps the vendor is actually selling normal stereo (3 pole) parts but taken on his own information, it "appears" at least to be 4 pole parts.

Glenn

First let me say that I think this is an awesome? project and thanks to?David Fainitski for creating it.

I understand that this project was done by directly creating a board layout without first creating schematics.
I think that's awesome but I'm old-school and I like reading schematics to help me understand a design.
If there is no objection, I'd be willing to work on entering a schematic for this project into a CAD system and share the result
Is it possible to generate a netlist from Sprint Layout 6.0?? (That would help in schematic verification).

73,
Scott? ?KJ7NLA

PS: I'm also interested in buying an ATU-10 once parts are available again.

Howard - the tandem match is the reason for DC continuity. The single turn primaries are in shunt with the 10 turn secondaries, which are connected to ground.

Here's a great link from Owen Duffy

Glenn, where did you find any info about 4 pin connection by my link ??
I can't find it.

Hi, Mike