The convention is that the relay contact symbol filled in with black is the resting position of the relay. The contact with the open triangle symbol is the one that is connected when the relay is energised.
You will find references also to the fact that using the rear socket has a current penalty of 20 or 30 mA, but I don’t mind about that. I switch between front and rear sockets when switching between transverter output and antenna, or 144 and 432 outputs, with no need to disconnect antennas or carry a switch.
Hope the relay replacement is successful. One thought though, have you compared the output power from each socket? Comparing receiver results can be misleading if not using a known stable signal source.
My ft818 is set to show swr on transmit. All bars lights up. Check with nanoVNA shows swr of 1,2. Connecting to rear shows 2 bars. So, I think it is relay. All test I do on receiving. Do not want my finals let smoke out
I am used to shematics that show relays in not energized state and with mechanical state, like this.
I failed to read properly your report on receiver sensitivity, which was based on a distant beacon signal. That is a good stable source of signal for comparison purposes. Sorry for missing that detail. This thread has come and gone in my attention over the last few days!
73 Andrew VK1DA/VK2DA
Have you considered asking Yaesu? The engineering guys at Yaesu UK are incredibly helpful and should be able to tell you what relay is used in that position.
I do not have the Technical Supplement for the 818 so cannot help further
Not find replacment relay yet. My friend (wizard of electronics) cleaned contacs with 1V, 500mA. I think that he is using special current, not avaliable to me with secret ingredient
