PSK on the FT-857D with VOX

NNote 2016-August.  — this is a pretty old article – my notes from way back. —

This applies to my Yaesu FT-857D and old Dell XP Setup
Audio Driver : Audigy for SoundBlaster 24bit
OS: Win XP

CAT cable: RTSystems  – USB to serial cable
Audio (Digital) Cable : direct connect  cable from xggcomms (UK).

QUICK SETUP FOR MAXIMUM POWER
RADIO SETTINGS

  • menu 34 Digital Gain 34
  • menu 40 Dig VOX 95
AUDIO CARD SETUP
  • volume 64%
  • wave 19%
  • Line In 14%
  • REC line in 22%
Anytime you start to transmit, adjust your computer volume for minimal indication on the ALC meter.
If the ALC is zero bars, your signal will be good.
Soundblaster 24bit
OS: Win XP

— UNDER CONSTRUCTION —
COMPUTER: AUDIO MIXER SETUP
select LINE IN for REC
select LINE IN
turn off “MIC” slider (MIC is too sensitive)

MASTER VOLUME RADIO CONTROLS FOR DIGITAL OPERATION *

set MODE to “DIG” – digital *  – This routes TX and RX audio to the data port on the FT-857.  The RX output is at a constant level that is not affected by the radios audio gain control.  This replaces the need to tap the audio from the headphone jack, for example, or put a microphone from the PC to the speaker.

set DIGITAL GAIN – MENU 37

Digital gain controls signal level on the TX data line from  the sound card.  This can be used in conjunction with the computer sound card volume control to adjust the amount of TX modulation.

Digital VOX – MENU 40  is used to key the transmitter based on  signal level from the computer.
if too low it won’t kick in.
With line in I find I have to set it very high … perhaps we’ll adjust later if we figure out why *. Set your rig to show the ALC meter while you transmit. If you have external meter, set that to power. *.

Set Power Menu  100 W
You are now ready to transmit. *.

TRANSMIT Adjust
SOUND CARD VOLUME 25-50% or until for ALC == ZERO or 1 BAR.
The audion input is now on the ALC threshold — your power is at it’s maximum.
Adjust radio’s DIGITAL GAIN if VOLUME is out of range or to compensate on the other end.
ALC indication on the radio display: if ALC == ZERO Your signal should be perfect now.
POWER ADJUST Increase / Decrease Volume The volume control on the computer is the only thing you need to adjust.
With ALC set to the threshold, this is maximum power.  Decrease digital gain to reduce power.

WHAT HAPPENS IF THE Power SETTING IS LOW:
If I change the power setting on the radio to lets say 25 watts without changing the audio level on the computer, the ALC will kick back in and you will still have to lower the volume on the computer. Another effect is that the range of power adjustment with the volume control may be much narrower before the ALC kicks in – lower volume. Now the power may be very low.

AUDIO FREQUENCY PASSBAND ~~ 1000-1500 or so RF output is attenuated outside the passband.
Best: Tune VFO and move the station to the passband.
Next best: raise the audio up until ALC registers O

POWER UP PROCEDURE
Power up radio before bringing up the computer application like “fldigi”.
Tune up radio on Freq for SWR.
Set radio controls for digital operations.
Set Computer Mixer controls. –possibly now is the time to switch radio mode to DIG —
start fldigi or digipan FLDIGI – check the tx attenuator preset – it’s possible this can be used to control power…

MODE Digital
M 75 Power 100
M 37 D Gain 34
M 40 D Vox 95

SOUND CARD MIXER
VOLUME 64% for Maximum at ALC threshold
WAVE 20%
Line In 14% (RECEIVE)
Line RECORD 22% (RECEIVE)

RADIO CONTROLS FOR DIGITAL OPERATION * set MODE to “DIG” – digital *.

set DIGITAL GAIN – MENU 37 to about 10 or 15. For my system it needs to be around 46 to meet the ALC threshold for maximum power. if too high, RF likes to get into the circuit and digital vox may stick on TX radio on/off may be necessary to reset – or turn down VOX or GAIN

set DIGIAL VOC – MENU 40 set to kick in andout reliably :: With Line in 95% necessary *. Set your rig to show the ALC meter while you transmit. If you have external meter, set that to power. *. Set Power Menu 75 to 100 W You are now ready to transmit. *. TRANSMIT Adjust SOUND CARD VOLUME 25-50% for ALC == ZERO or 1 BAR [ my system Adjust radio’s DIGITAL GAIN if VOLUME is out of range. ALC indication on the radio display: if ALC == ZERO Your signal should be perfect now. POWER ADJUST Increase / Decrease Volume The volume control on the computer is the only thing you need to adjust. WHAT HAPPENS IF THE SETTING IS LOW: If I change the setting on the radio to lets say 25 watts without changing the audio level on the computer, the ALC will kick back in and you will still have to lower the volume on the computer. Another effect is that the range of power adjustment with the volume control may be much narrower before the ALC kicks in – lower volume. Now the power may be very low. AUDIO FREQUENCY PASSBAND ~~ 1000-1500 or so RF output is attenuated outside the passband. Best: Tune VFO and move the station to the passband. Next best: raise the audio up until ALC registers O Bottom line is, anytime you start to transmit, adjust your computer volume for minimal indication on the ALC meter and your signal will be beautiful. POWER UP PROCEDURE Power up radio before bringing up the computer application like “fldigi”. Tune up radio on Freq for SWR. Set radio controls for digital operations. Set Computer Mixer controls. –possibly now is the time to switch radio mode to DIG — start fldigi or digipan FLDIGI – check the tx attenuator preset – it’s possible this can be used to control power…


4 Responses to “PSK on the FT-857D with VOX”

  1. I’m now using a USB CAT cable, which eliminates the Digital VOX requirement, and adds a lot of features with HRD, DigiMaster, and the HRD Log applications.

  2. do you have a cat cable and a audio cable?

    • Yes. VOX works quite well but a CAT interface is direct – mades digital simpler once I got it going. Still good to remember how to use the VOX though. On my radio e.g. 60M won’t go into digital mode, and it has to be VOX or full manual. marksun aka KH6DK

    • Hi sorry – I don’t expect to see any comments so I never check — yes, I guess that info is missing from my notes. peter kh6dk

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