A common fault on the SGC range of antenna tuners is a reduction in receive performance as they get on in years. This can be attributed to contamination on the relay contacts since SGC stoped using fully sealed relays. Any small condensation inside the tuner makes it’s way into the relays and causes contamination on the contacts as they are hot switched. The best thing to do is to replace all 26 relays with new units…
You can see the contamination on this relay with the top case removed.
The PCB has to be removed from the case to access the underside and remove the relays. It’s not a hard job but you have to be careful not to apply to much heat and risk lifting the PCB traces.
All 26 contaminated relays removed.
You can easily see the damage to the contact in this picture.
New relays ready to go in. I used Panasonic ALW1PB12 relays. They are rated for 16A which is a little higher than the original SGC part which was 10A.
All new relays installed.
Does it make a difference? Yes, very much so. I tested before and after and can see up to a 9Db difference in received signal strength across the board. I dare say it will also handle a little more power now with higher capacity relays (original rating is 150W) but I don’t know if the other components will like it! A job well worth doing to extend the life of this great tuner.