Construction Progress

[M0ATV]

Well, finally found enough time to start putting all the pieces onto the digilite board tonight, I purchased two boards, one for 23cm & the other for 70cm use, so thought it would be best to get the AD8346 chip on first on the 23 board & AD8345 chip on the 70 board, after what seemed to take forever, & after a VERY good examination under a strong magnifying glass & some continuity tests, they seemed to be fine. Then the extremely tiny surface mount C8,C9, C30 & C31 blimey, the fine tipped iron looked huge in comparison, anyway, fitted 15 inc all top IC's & decided thats enough for tonight, will crack on tomorrow after work, would like to hear other peoples progress in assemby of their own boards, will add more as I get it down, 73 Tony M0ATV Stockport

[G4OHV]

Also started mine tonight, managed to break L5 though. Noticed a difference between overlay and parts list....C24 shown as 100pf on overlay, but 220pf in parts list. so Intend to check over the rest of the caps and resistors tomorrow against the drawing for any more errors. Also the electrolytics could have been a size larger, as in the finished photo.
Wasn't brave enough to tackle the IC's tonight hi hi.

Regards

Col

[G1LWX]

Hi Tony
There are two schools of thought about fitting the mod chip one is to solder each leg individually doing the grounds first.
The other is to blanket solder all the legs together then solder wick the excess solder off. I must admit that I chose the first option.
Glad to see that you are getting going will be good to have another signal up here Hi.

73's
Mike

[M0ATV]

Also started mine tonight, managed to break L5 though. Noticed a difference between overlay and parts list....C24 shown as 100pf on overlay, but 220pf in parts list. so Intend to check over the rest of the caps and resistors tomorrow against the drawing for any more errors. Also the electrolytics could have been a size larger, as in the finished photo.
Wasn't brave enough to tackle the IC's tonight hi hi.

Regards

Col

Thanks for posting Col, I'll have a closer look at mine to also check for any parts listing errors, after all it is a HUGE undertaking the batc have taken on for this project so there will be a few hiccups along the way, & regarding the IC's, this was the only bit putting me off starting the assembly a week or so earlier, kept racking my brains thinking of a way to solder the thing correctly, ended up looking at quite a few videos on Youtube regarding soldering techniques for SMD projects, also having solder wick & liquid flux combined with a filed down & polished solder tip made a massive difference in the end.

In regard to what you mentioned MIke, I ended up blanket soldering the board IC strip area, solder wicked most of it off so the IC could sit flush then using the flux & very fine solder gently did each leg as carefully as possible, while I was feeling brave I did both boards so the worst task was over & done with !!

[G4OHV]

Checked overlay - C24, as above, C22, C25, C32, C33 should be 1n2F, shown as 1nF, and parts list - R28, R38 should be 100R, when checked against the drawing.

Regards

Col

[G4EWJ]

It's the first time I've ever had to solder anything as small as the modulator. I didn't really have a small enough tip, so I used the chisel tip. I soldered opposite corners and then did the single pins by holding the tip on its side touching track and pin for a second, moving the iron back slightly and then putting solder into the gap.

It worked fine on the first side, but I got a couple of bridges on the second side. They were behind the pins and I couldn't get them out. I had to resort to the ballistic de-soldering technique. I applied plenty of solder and then banged the pcb on its side against the desk. It worked, but it would probably have been better to do it with only the modulator on the board to stop solder getting caught by other components.

Anyway it's up and running. I don't have a MAR-6, so I just bridged the gap and used a resistor as a quarter wave antenna. I'm receiving it on the floor below, although with only 100uW or so, antenna placement is a bit touchy.

Brian

[G4OHV]

Completed my board except for L5 which I trashed yesterday!. Used plenty of flux and a pointed bit. That mod chips tiny! Think I will have a go at a 70cm varient now.

Regads

Col

[G4EWJ]

The modulator pin spacing looks huge compared to the FT2232H chip, even though they are 0.65mm and 0.50mm. Must be an optical illusion.

Brian

[M0ATV]

Completed my board except for L5 which I trashed yesterday!. Used plenty of flux and a pointed bit. That mod chips tiny! Think I will have a go at a 70cm varient now.

Regads

Col

Damn ! the AD8346 mod chip was easy in comparison with L5 inductor, mine looks impossible to fix to the solder pads on the board, it is minute, the legs are under a plastic shroud, is there another equivalent part I can use instead of the Farnell L5, only got a few more bits to go on after this & I'm finished.


Here's a close up of my L5next to a 1p piece, you can make out the lower legs that have to be fixed to the solder pads, but not sussed out how to yet....

[M0ATV]

Well bar a few last components ( U5, L5, MAR-6 mimmic, & led & optional R27,R28 ) I've just about finished mine, not powered up or tested yet, fingers crossed, trying to source a slightly bigger ver of L5 to get that last fiddly bit fin, must admit not done any soldering for years, so really enjoyed putting the kit together.