I have a TS-830, so it should be similar. You have three knobs: Drive, Load, and Plate. You'll also use the Mode switch and Meter switches.
Set the band & frequency to where you want to operate. Later during your hamming session, if you move more than 150 kHz to 200 kHz or so, you want to retune - depending on your antenna's bandwidth. Short antennas, or lower bands, need more frequent retuning as you change frequency.
ON RECEIVE
1. Listen to signals or static on your antenna and peak the drive control for maximum volume.
2. Switch to a dummy load (or your antenna only if you absolutely must).
MODE = TUNE & METER = CURRENT
3. Set MODE switch to 'TUNE' - this puts a small signal thru the radio - so you won't hurt the finals.
4. With the METER on 'CURRENT', peak the meter with the DRIVE knob.
5. With METER on CURRENT, *dip* the meter with the PLATE knob - it may have a very broad dip. If it is hard to see, try the METER in 'RF' position and *Peak* the RF using the Plate knob. If you have trouble getting a reading, advance the ALC knob a little.
METER = 'RF'
6. Switch the Meter to 'RF' and *peak* with the Load knob
7. (This step is optional for perfectionists) With Meter on 'RF', *peak* with the Plate knob
MODE = 'CW', METER = 'RF'
8. SWITCH Mode to CW. (NOTE: Make sure the VOX is on and if you have a key, hold it down while tuning).
9. Repeat 7 & 8, gently nudging up with the Load knob, and then peaking the meter with the Plate knob, until you get a reading of 90 to 120 Watts. (Again, if you have trouble getting a reading as high as 90 watts, advance the ALC knob a little).
IMPORTANT: DO NOT TRANSMIT IN CW MODE FOR MORE THAN 15 OR 20 SECONDS AT A TIME: REST 5-10 SECONDS BETWEEN. It can decrease the life of those finals, and also make you VERY unpopular to the poor guys you're tuning up on top of (you DID check if the frequency was free, right? ;^) -- a dummy load is a good investment).
SWITCH FROM THE DUMMY LOAD TO THE ANTENNA
10. If you have a tuned antenna, then you are ready to go. If not, then tune your antenna tuner on the air - DO NOT TOUCH THE 520 - only the antenna tuner if you are using one.
METER = ALC (ADJUSTING ALC/MIC KNOB0
11. In CW, use the ALC knob to set the CW so that the needle bounces just into the 'good' range - shown by tick marks over the middle 2/3 of the meter or so.
In SSB, talk into the mic and adjust the MIC control so your voice peaks stay around the middle of the 'good range.'
12. HAVE FUN!