TS-520SE info
Mike:
1. CW filter option. This is a nice add-on...this filter when installed narrows(reduces) the bandwidth of the RX...allowing for easier copy of CW signals in a crowded band...ie: Normal bandwidth in SSB is about 2.7 kHz wide...optional CW filter is 500 Hz...this helps reject signals on either side of the center of the filter.
I have several rigs with optional CW filters and use them during contests or when the CW segments are busy. You can have 10+(or more) CW stations in the same bandwidth as 1/ SSB station...
Listening to many stations in CW when they are close in frequency to each other can be tricky sometimes till you get accustom to doing so...but the filter is not required for CW operation...just a personal option for later when you begin to operate CW quite a bit...
INRAD filters(International Radio) makes the best ones but they are about $100+/the KWD version are maybe a little less when you can find them(kinda rare these days)
2. Fixed channel operation:You can add up to 4 crystals on the board inside the rig for SINGLE frequency operation.
These lock the rig in a frequency selected for net or favorite band location and by-pass the VFO operation in transmit...you can use a couple variations with and without the VFO but that is how it was made to set-up.
You can not place crystals on this board...ie: 6 meters and expand the rigs operation.
3. Drive Control: This has a dual purpose/ it peaks the RX section or (preselects) the first stage of the receiver for better sensitivity AND peaks the predriver stage of the transmitter for each band.
When you change bands tweak the drive control for best receiver by ear and this will get you closer for max output on the transmitter(reduces tune-up time)
This is something as you use the rig more often you get accustom to using...but this is normal for many older rigs.
4. Reducing SSB output: Best way here is to reduce the Mic Gain control...do NOT detuned the drive or adjust the Plate/Load controls as this can detuned the final stage and increase heat and shorten tube life...best to tune a for proper output and lower the Mic level and turn off the processor...that make sense?
Hope this all helps and I did not bore you to sleep...good questions!
All the Best
BJ
The 8 pin connector on the rear panel is for amplifier switching and receiver(speaker muting) when using an external amp...when using VOX OR PTT the amp is auto keyed with the internal relay of the radio...it also provides ALC control to the radio to reduce output if you are driving the amplifier to hard...this reduces splatter and provides for much cleaner SSB operation and greatly improves tube life in radio and amplifier as most amps like TL-922/L4b and newer ceramic tube amps require only about 50 to 90(or less) watts for recommended drive to proper output...GL/BJ