I have a Swan 500 and spent quite a bit of time restoring it. It is now working well on receive and transmit. One thing that has me puzzled though: when you back off the audio control with the RF gain sitting at around say 12 or 3 o'clock the S Meter moves to the right and if you reduce the audio down far enough the S Meter is at the end of the scale. I have replaced the electrolytics and the diodes in the RF gain circuit and all the valves have been replaced. I can see that the audio pre-amp, the 12AX7 V10 is related to the other 1/2 of the 12AX7 in the product detector, which is related to the second IF v9 where the S-meter circuit is found. As to how the Audio Control is controlling the S-Meter I do not understand. Any help or advice would be appreciated. Thanks, Milton VK6UG.