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Cabinet and Chassis Restoration and Refinishing For help with cabinet or chassis restoration (non-electrical), please leave a message here. |
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29th Mar 2021, 11:31 am | #1 |
Banned
Join Date: Feb 2017
Location: Bedfordshire, UK.
Posts: 601
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Yaesu FRG7700 shields cleanup
I have a used FRG7700 that appears to have seen better days but with other issue I am looking at possibly cleaning up the Shielding boxes if possible. Not sure whether at this stage to completely remove and check innards but there appears to be no corrosion to pc board or and dry joints etc within these areas. Also tackling an issue with the band switch that still continues to not select band changes and throwing out irregular data for the tuning guide frequency display to follow! Example id go to position 20 and it may show 9 something (all Digits working in display) but not following and counting via the dial change rotary etc. Have tried some switch cleaner and backward and forward turns to try and clean but to no avail, so may be looking for replacement switch if available.
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2nd Apr 2021, 4:51 pm | #2 |
Octode
Join Date: Dec 2019
Location: Owston Ferry, North Lincolnshire, UK.
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Re: Yaesu FRG7700 shields cleanup
There used to be a tinning liquid available for tinning pcbs, so that the all the bare copper tracks became tinned. I wonder if it would work on your screening covers, although they will need a good cleaning first before being dipped. It looks like something has attacked the tinned plate surface, maybe moisture.
Dave
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2nd Apr 2021, 6:48 pm | #3 |
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Join Date: Mar 2012
Location: Fife, Scotland, UK.
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Re: Yaesu FRG7700 shields cleanup
Tinning liquid is used for electroless tin plate. THere is a comparable copper electroless process.
Original screens are tinplated mild steel and were stamped and folded from pre-plated sheet stock. Plating isn't difficult unless you want chrome. The difficult part will be de-rusting and preparing. You can silver plate using spent photo darkroom chemicals as the raw materials. David
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3rd Apr 2021, 1:41 pm | #4 |
Octode
Join Date: Dec 2019
Location: Owston Ferry, North Lincolnshire, UK.
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Re: Yaesu FRG7700 shields cleanup
As a further comment, when cleaning the metal surface don't use anything abrasive, as any scratches will show through the tin plate finish. You most likely will need to use a pickling solution to prepare the metalwork. Likewise don't touch any of it with bare hands, or you will always see your finger prints through the tin plate finish. The plating is only a few microns thick, and is much thinner than a spray paint finish.
Dave
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Quote "All is hyperthetical, until it isn't!" (President Laura Roslin, Battlestar Galactica) |