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Broadcast FM Reject Filter: loose contacts

Posted: Sat Jun 30, 2018 6:10 pm
by Remon
While browsing Youtube I accidentally found this video:

https://youtu.be/p4qHqQ1-qY0

Curious as I am I opened my filter finding the same issue. Unfortunately I didn't make a before picture. They used soldering wire which was hard the melt, even on high temperatures. I added 60/40 resin core solder and removed it with desoldering wick. I repeated it a couple of times until it had a solid connecting with the circuit board.

After:

Image

Image

Re: Broadcast FM Reject Filter: loose contacts

Posted: Sun Jul 01, 2018 11:41 am
by rtlsdrblog
Hey sorry about those issues. The change in solder might have something to do with new environmental regulations in China. This solder is much harder to work with.

What was the behavior of the filter before the reflow?

I'll check with the factory and make sure it doesn't happen in future batches. But newer batches shipping now shouldn't have this problem anyway as we added further QC checks.

But if anyone has the same issue and can't/is unwilling to reflow the solder themselves please email us at [email protected].

Re: Broadcast FM Reject Filter: loose contacts

Posted: Sun Jul 01, 2018 12:33 pm
by Remon
The filter was fully functional before I did the resoldering job. I just wanted to make sure the connections didn't come of at some point.

By both tightening the nuts and tightening the SMA connectors, there will be some force between the SMA socket contacts and the PCB. Especially if the RTL-SDR dongle and the filter are connected to each other while someone tighten them by twisting them with both hands. The contacts/legs on mine didn't bend as shown in the video since I didn't applied force to it.