I won't make a full report of my build , since all information on this autotuner is available online.
This is the github page where you can find it all.
Some nice descriptions can be found by Googling ATU-100.
And visit these pages by R0AEK with some very helpful information (in Russian, but Google does a decent translation). There are 4 parts.
So here just some pictures of what I did, from the package arriving from China (in 11 day's, that was quick !), to the final result.
The parts arrived in a nice plastic box, and then in some plastic bags.
The SMD's all pre-soldered.
The SWR bridge
All coils ready, with some other components.
Adding the 15 relay's.
Winding the tandem match was the hardest part. TIP : I removed a few strands from the RG58 center conductor to make it fit the holes in the PCB.
All parts of the case ready to assemble.
Detail of the front panel
Back panel
Back panel inside.
Boxed it !
Making the connections to the board is not complicated, see markings on the main PCB.
GND and + is for the 12V DC power supply or battery.
GND and B is for the big TUNE button
On the 5 pin connector, only 4 pins are used to connect the OLED display:
VCC goes to VCC on the display
GND GND
DAT SDA
CLK SCL
Finally there are two optional buttons, they connect to two pads on the underside of the PCB, the other side of the buttons goes to GND of course.
B1 is the AUTO button (it shows as a DOT on the display).
B2 is the BYPASS button (it shows as an UNDERSCORE on the display).
B1 is the AUTO button (it shows as a DOT on the display).
B2 is the BYPASS button (it shows as an UNDERSCORE on the display).
This pictures show clearly where those pads are, but be careful with static when soldering, the pads are directly connected to two CPU pins. It is advised to put a 100 nF capacitor over each of those buttons, to avoid RF getting directly into the CPU.
Almost finished
The last step was making a nice cover. I used the top cover from an old Macbook Pro laptop, and was able to save the "Apple" ... hi.
Adding a high brightness LED, using only an extra 5 mA to light the Apple logo, this is the result !
I only did a short test on my home antenna, and all seemed to work ok.
More extensive testing to follow during my SOTA or other /P activities ...
73,
Luc - ON7DQ
Nice job. Reminds me i must box mine.
ReplyDeleteVk3pe
Well done. Very clean.
ReplyDeleteGood job! How does it work?
ReplyDeletehow many windings for each inductor?
ReplyDeleteWinding info is on the circuit diagram on github
DeleteThank you for the pictures as the information on is a bit vague especially T2 and the display wiring Also I will have to trace the board/ cct diagram to work out the wiring of the auto and bypass switch Also put in a set of 5 pins for the display but should hav eonly used 4 so now a pin short
ReplyDeleteCan you show where on board you connect TUNE AND BYPASS Switches. Also does tuner go to bypass when power is off.
ReplyDeleteMarked up as B1 and B2 on the underside of the board...
DeleteDoes the antenna hook to the "in", in from anntenna and out to radio?
ReplyDeleteThink of the path for a 'transmitted' signal (perspective should be the other way around):
ReplyDeleteRadio is connected to IN,
Antenna is connected to OUT.
I am not much of an electronics person, unfortunately. I ordered one of these pre-assembled on eBay, but they have failed to include the instructions on where to wire in buttons and the display. I contacted them and they gave me links to the github--also not much help with details.
ReplyDeleteI have a 2-pin header labeled GND and B (bypass switch maybe?), another 2-pin header labelled GND and + (tune switch maybe?), and then a 5-pin header labeled MCLR, VCC, GND, DAT, CLK
the little display has a 4-pin header labeled GND, VCC, SCL, SDA
Any idea how that would wire together? Thanks in advance!
-- Chuck KV3G
Thanks for the connection info. I have purchased a populated board but was not sure where to connect the wires to the OLED and the B1/B2 switches. Your article made it very clear.
ReplyDeleteBest regards
Neil
G7AQK