Vertex Standard FT-950 manual Miscellaneous AFSK-Based Data Modes

FT-950

Operating Manual

recommend that reduce the transmitter power to 1/3 ~ 1/2 of its normal maximum via the Menu item “111 TGEN TX PWR”.

Advice:

If you need to adjust the output level from the “DATA OUT” pin (pin 5) of the RTTY/PKT jack on the rear panel of the transceiver, please use Menu item “061 RTTY OUT LVL”. For the input level from the TU, there is no adjustment of the FSK input level (Pin 4) of the RTTY/PKT jack; please make any needed level adjustments at the TU side.

The Mark/Space Shift utilized in most Amateur RTTY operation is 170 Hz. Other shifts may be configured, however, using Menu item “062 RTTY SHIFT”. The FT-950 is set up for “high tone” operation (centered on 2125 Hz) by default, but you may configure it for low tone (1275 Hz) operation using Menu item “063 RTTY TONE”.

You may find that you are unable to decode some RTTY stations, even if they are of sufficient signal strength. If this is observed, there may be a Mark/Space polarity problem between your station and the other station. If so, try setting Menu item “059 RTTY R PLRTY” to “rEU” (“Reverse”) to see if that permits copy. A separate Menu Item permits reversal of your transmitter’s Mark/Space polarity: “060 RTTY T PLRTY”.

Quick Point: In the FT-950, “RTTY” is a mode defined as being an “FSK” mode, whereby the closing and opening of a keying line (to ground) causes the Mark/Space tones to alternate. The RTTY mode is not an AFSK based mode in this transceiver, and the AFSK output tones from a TNC will not cause Mark/Space shifting to occur. Use the “Packet” mode for AFSK-based Baudot and other data modes.

Miscellaneous AFSK-Based Data Modes

The FT-950 may also be used for a host of other SSB-based Data modes. Please set up your system using the illustration as a guideline.

Quick Point: When you have configured Menu item “114 TGEN VOX SEL” to “dAtA,” the transceiver will operate in a “VOX” mode, and it is not necessary to connect a PTT line. This makes for very convenient interfacing to computer Sound Cards, etc.

108 Vertex Standard Co., Ltd.