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ubitx v4 spurs fix confusion #ubitx #ubitx-help


Chris [N7CCX]
 

Hello fellow hams, I am currently in process of assembling the ubitx I got this week.. I noticed on ubitx.net there was a spurs fix that uses inductors.

This is what the mod looks like, now those two inductors are on the traces. My question is on the traces, am I to scratch off the top layer to expose trace to then solder onto? I know where the toroid was is a solder pad... However, no solder pad on the bottom (relative on the picture) confused me and wondering if its just needing a trace exposed to solder onto.  

Pic of mod/fix (red circled areas are the ones I'm asking about):


The relay fix, I am already planning on and those are easy to resolve :)

Thanks, everyone!


Gary Anderson
 

Yes, for this modification: remove the solder mask on the traces you have highlighted with the red circles.
Comment: the workmanship on solder mask removal was done so well on this example that there is no visible collateral damage.

Rgds,
Gary


Paul Galburt - K2AYZ
 

Excellent picture - can you state the part number and mfr of the SMD inductors you are using?

Thanks,

73

Paul


 

They are from a sample book. Marking is S+M which I understand is TDK.
They are shielded and have a DC resistance of less than 2 Ohms. 1210 size if I remember right.

Raj

At 25-01-19, you wrote:
Excellent picture - can you state the part number and mfr of the SMD inductors you are using?

Thanks,

73

Paul


 

Thanks Gary,

Actually the component is covering the area!

I have some ceramic tipped screwdrivers for ferrite slug adjust. They are sharp and I used one to gently scrape away
the resist coating.

Raj

At 24-01-19, you wrote:
Yes, for this modification: remove the solder mask on the traces you have highlighted with the red circles.
Comment: the workmanship on solder mask removal was done so well on this example that there is no visible collateral damage.

Rgds,
Gary


q q
 

What is the actual value uH of the two SMD parts you are using here?

Thank you
Bob
N1ETS


MVS Sarma
 

680nH


On Fri, 25 Jan 2019, 7:45 pm q q via Groups.Io <bzmdrc=yahoo.com@groups.io wrote:
What is the actual value uH of the two SMD parts you are using here?

Thank you
Bob
N1ETS


_Dave_ AD0B
 

Ah that explains why my radio didn't like 680uH I think that was value I saw posted. Can confirm that 680 uH really attenuates the signal.


Ted
 

It looks to me as if you've bypassed C211 with that configuration.  The inductor contacts the trace leading to the outboard side of that cap rather that the inboard side of the cap as per the original inductor. 

The swap on the left doesn't do that. 

Is that intentional, part of the upgrade?


Ted


 

You can do without 211 and 215. I looked for a convenient spot and put it there.
Those two caps are for DC block and there is no dc there.

Raj