25-10-2020, 09:59 AM
Hi,
I recently acquired a Lowe HF-150 radio receiver in quite a sorry state, as the alkaline batteries fitted had leaked...
This post is solely about the 3.5mm jack sockets on the rear - there are three of them and after a bit of searching I found out that they are Switchcraft 35RAPC2AV types.
In this radio, two of them needed attention or preferably replacement.
As you can see from the picture, they had the dreaded blue corrosion on the contacts and I firstly tried to buy a couple : However, Farnell wanted £28 to import two from the US, RS only sell them in packs of 50 (80p each), and Mouser & Digikey wanted £14 & £12 extra respectively for handling charges on small orders...
This was not economic as far as I was concerned, so I thought I'd have a go at cleaning up the existing ones as they were otherwise destined for the bin...
Luckily, the clear plastic lid on the side just lifts off and I decided to give them a quick bath in some acid !
Checking the kitchen cupboard I found some 'Sarsons Vinegar for pickling' which is distilled and stated as being 6% acidity.
On being covered in acid, the blue corrosion immediately started 'fizzing' and after about a minute (and the fizzing had stopped) I removed them and thoroughly rinsed under the tap.
After this I doused them in IPA, then blow dried with a hot-air gun from a reasonable distance.
The results can be seen below with all the blue corrosion dissolved away and the majority of the metal parts clean and shiny.
The exposed base metal 'coppery' parts I covered with a small amount of petroleum jelly. Luckily, all of the parts which make contact with an inserted plug, plus the 'break' contact were fine and hadn't suffered any damage.
Finally, I tested everything for continuity with the help of a plug and found them to be excellent !
Just need to be re-fitted before attacking some other problems with this radio - more later.
Andy
I recently acquired a Lowe HF-150 radio receiver in quite a sorry state, as the alkaline batteries fitted had leaked...
This post is solely about the 3.5mm jack sockets on the rear - there are three of them and after a bit of searching I found out that they are Switchcraft 35RAPC2AV types.
In this radio, two of them needed attention or preferably replacement.
As you can see from the picture, they had the dreaded blue corrosion on the contacts and I firstly tried to buy a couple : However, Farnell wanted £28 to import two from the US, RS only sell them in packs of 50 (80p each), and Mouser & Digikey wanted £14 & £12 extra respectively for handling charges on small orders...
This was not economic as far as I was concerned, so I thought I'd have a go at cleaning up the existing ones as they were otherwise destined for the bin...
Luckily, the clear plastic lid on the side just lifts off and I decided to give them a quick bath in some acid !
Checking the kitchen cupboard I found some 'Sarsons Vinegar for pickling' which is distilled and stated as being 6% acidity.
On being covered in acid, the blue corrosion immediately started 'fizzing' and after about a minute (and the fizzing had stopped) I removed them and thoroughly rinsed under the tap.
After this I doused them in IPA, then blow dried with a hot-air gun from a reasonable distance.
The results can be seen below with all the blue corrosion dissolved away and the majority of the metal parts clean and shiny.
The exposed base metal 'coppery' parts I covered with a small amount of petroleum jelly. Luckily, all of the parts which make contact with an inserted plug, plus the 'break' contact were fine and hadn't suffered any damage.
Finally, I tested everything for continuity with the help of a plug and found them to be excellent !
Just need to be re-fitted before attacking some other problems with this radio - more later.
Andy
