[CQ-Contest] MORE TS-830 INFO

[T. A. Russell]

TS-830  Frequency Display

The digital readout on the TS-830 (and 530) represents the zero-beat
carrier frequency.  Of course, no one listens to zero beat on CW and
therefore, the receiver must be tuned offset from the carrier by the 
desired audio pitch.  The 830/530 radios have an 800 Hz offset.

Most people prefer to listen to a lower pitch, usually around 400 Hz.
When a radio with an 800 Hz offset is tuned to produce a 400 Hz
pitch, then the transmit signal will be 400 Hz away from the received
signal.  The radio's RIT or XIT controls can be used to align the CW
transmit and receive frequencies with the following procedure.

On transmit, the display will shift to the actual transmit carrier
frequency.   Set the display to show 7000.0  (or any desired frequency
ending in 00.0) when in the TRANSMIT mode.  Return to the RECEIVE 
mode and turn on the calibrator signal (which is also on 000.0) and 
adjust the RIT for the desired pitch.  The RX and TX frequencies are 
now aligned.  Note the DIFFERENCE between these displayed 
frequencies.  

If you prefet to use the XIT to set your offset, you can adjust the XIT
control to produce this same difference between the RX and TX readout
and your RX and TX signals will be aligned.

The big disadvantage to this setup is that you cannot set the RIT and XIT
controls independently so if you set your offset to your desired pitch,
you no longer have the freedom to use them for their intended purpose.

Fortunately, there is a simple solution to this dilema.

The CW offset is determined by a small inductor in the VFO module.
Replace this inductor with a 2.2 uH choke and you will have a 400 Hz
offset without resorting to RIT/XIT adjustment.  To access this coil,
remove the 4 screws around the VFO and carefully pull the VFO unit
out from the radio.  Disconnect the cables from the back and remove
the cover.  There is a small solenoid wound coil visible on the board.
This is the CW offset inductor.  I believe it's value is around 1 uH.
If you cannot find a 2.2 uH choke, you can add a few turns to the 
existing part or wind your own choke.  The difference between the
RX and TX frequency displays will tell you the offset.  

de Tom - N4KG

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