Nice! Another technique I've seen for this kind of cleaning is to use a strip of plain paper with a few drops of IPA on it and then do the wiggle wiggle with the contacts closed.
Im fixing one of these at the moment. It had no life at all. With a fair bit of work I now have transmit and receive but the transformer on the display board is shorted so no display and -5v for some op amps. I powered the display with a bench supply it all works including the driver ic. I'm contemplating some how deglueing the tranfromer and re winding it 🫣 love your channel BTW 73 👍😊
make sure to clean the contacts on the SR-202 tx-rx relay too, which is located on the lowpass filter board at the back of the transceiver. Unsolder the relay from the board, and you can fully disassemble it. The contacts get oxidated, especially on the receive side. I am currently repairing an IC-730, but the 100 watts variant. 73!!
The worst thing you can do to a relay like this is use a abrasive. You will completely remove the plating off the contacts that is guaranteed to fail again and again in very short order. Abrasive diamond contact cleaners are meant for industrial contactors that use solid silver contacts, they are not plated. Just cut a thin strip of plain paper and dampen with your favorite contact cleaner is what should be used for relays. No different than when I was a kid and we had to clean the contacts on the thermostat with a dollar bill at the beginning of winter every year.
I absolutely agree with you about not using an abrasive. What's your opinion on using a burnishing tool that's specifically made for cleaning contacts?
According to the 3M spec sheet: polishing soft materials like plastic and soft metal alloys, it is prolly good enough for cleaning relay contacts. I was appalled at the word "sandpaper" at first.
@@jimhall9360 I wouldn't use contact burnishing tools either. They are designed for industrial contactors that use solid non plated contacts. Any type of abrasive on a relay contact, even a burnishing tool would remove the microscopically thin electro plating from a relay contact.
@@PapasDino Doing well. RUclips is a blessing and a curse. It led to me being completely overwhelmed with work. I mainly only work on amateur, business/commercial radios now. Going to take all the test to get my GMDSS Radio Operator / Maintainer license with radar endorsement in a couple of weeks. Those test make the Extra Class Amateur test look like a walk in the park (which it was). Wish me luck. Merry Christmas. Mike KC3OSD
Most relay issues in ham radios could be avoided if the manufacturers would have provided the requisite wetting current. Every small signal relay datasheet will say its necessary, yet the manufacturers all seem to ignore it. I've restored a number of impossible to find relays for FT-102s with a drop of deoxit on the contacts, an Arduino programmed to cycle the relay a few thousand times, and a couple hundred mA DC applied through the contacts.
Great tip, you saved the day. Thin strip of coffee filter paper inserted into the contacts and wetted with alcohol. Good wet strength. Thanks again.
Nice! Another technique I've seen for this kind of cleaning is to use a strip of plain paper with a few drops of IPA on it and then do the wiggle wiggle with the contacts closed.
Im fixing one of these at the moment. It had no life at all. With a fair bit of work I now have transmit and receive but the transformer on the display board is shorted so no display and -5v for some op amps. I powered the display with a bench supply it all works including the driver ic. I'm contemplating some how deglueing the tranfromer and re winding it 🫣 love your channel BTW 73 👍😊
make sure to clean the contacts on the SR-202 tx-rx relay too, which is located on the lowpass filter board at the back of the transceiver. Unsolder the relay from the board, and you can fully disassemble it. The contacts get oxidated, especially on the receive side. I am currently repairing an IC-730, but the 100 watts variant. 73!!
The worst thing you can do to a relay like this is use a abrasive. You will completely remove the plating off the contacts that is guaranteed to fail again and again in very short order. Abrasive diamond contact cleaners are meant for industrial contactors that use solid silver contacts, they are not plated. Just cut a thin strip of plain paper and dampen with your favorite contact cleaner is what should be used for relays. No different than when I was a kid and we had to clean the contacts on the thermostat with a dollar bill at the beginning of winter every year.
I absolutely agree with you about not using an abrasive. What's your opinion on using a burnishing tool that's specifically made for cleaning contacts?
Mike - glad to see you're still alive and kicking...Buddy and I have been hoping you'd resurface at some point. Hope all is well. 73 - Dino KLØS
According to the 3M spec sheet: polishing soft materials like plastic and soft metal alloys, it is prolly good enough for cleaning relay contacts. I was appalled at the word "sandpaper" at first.
@@jimhall9360 I wouldn't use contact burnishing tools either. They are designed for industrial contactors that use solid non plated contacts. Any type of abrasive on a relay contact, even a burnishing tool would remove the microscopically thin electro plating from a relay contact.
@@PapasDino Doing well. RUclips is a blessing and a curse. It led to me being completely overwhelmed with work. I mainly only work on amateur, business/commercial radios now. Going to take all the test to get my GMDSS Radio Operator / Maintainer license with radar endorsement in a couple of weeks. Those test make the Extra Class Amateur test look like a walk in the park (which it was). Wish me luck. Merry Christmas. Mike KC3OSD
What used to work well was a tool I had for cleaning point contacts on old ignition systems.
Most relay issues in ham radios could be avoided if the manufacturers would have provided the requisite wetting current. Every small signal relay datasheet will say its necessary, yet the manufacturers all seem to ignore it. I've restored a number of impossible to find relays for FT-102s with a drop of deoxit on the contacts, an Arduino programmed to cycle the relay a few thousand times, and a couple hundred mA DC applied through the contacts.
Just use a sheet of paper to clean delicate contacts as paper is abrasive and not harsh
😀👍