To enable one
the make recordings, as well as to be able re-transmit such using
a Computer and Soundcard, one will need to fabricate an interface
which will connect the TS780 to the Computer Soundcard
Interface
Audio transformers
are incorporated which provide complete isolation between the Transceiver
and the Computer. I use in-expensive Stancor Audio Transformers (TTPC-2)
which are 1:1 (600:600 ohm)
The Soundcard
is connected to the TS870 via the Accessory Plug on the back of the
Transceiver. The following diagram (Fig 1) shows the pin-outs and
audio cabling connections (see page 7 of your TS870 Instruction Manual
for ACC2 pinouts)
Parts
List
Two 600:600 ohm
audio transformers (Stancor TTPC-2)
1K ½W Resister
1K linear Pot and knob
Push Button or Foot Switch to key TS870 to TX Recording (Playback)
Suitable box to house interface
Screened audio cable to make connection between Interface and Soundcard
Two 3,5mm Stereo phono plugs
One 13 Pin Din Plug
Audio
Leveling
Audio levels
need to be properly set in your Recording Software, and one must make
sure that the audio is not over-driven
Audio levels
must also be setup in the TS870 Menu’s. Menu number 20 and 21
are used to set these parameters
Menu
Setup (see page 25 of your TS870 Instruction Manual)
Menu # 21 (PKT
IN) controls the audio input level (this level can be set within the
TS870 from 0 – 2)
Menu # 20 (PKT
OUT) controls the audio output level (this level can be set within
the TS870 from 0 -9)
Finally the attenuator
in the Interface (Fig 1) can be used to “fine tune” the
output from the TS870 to the Soundcard Line Out
Keying
the TS870 for Playback
The only way
to “key” and re-transmit the recorded audio is to use
the PTT keying line in the ACC2 plug. Pins 9 and 8 are used for this
purpose. Pin 8 is + and Pin 9 is ground. I use a push button connected
to these pin-outs, a foot switch could also be used
The audio paths
used in ACC2 are completed independent from the front panel controls,
so the TX Button will not work, hence the need to key the rig from
Pins 8 and 9
Recording
Software
Any audio software
with record capabilities can be used for recording and playback. I
personally use CoolEdit Pro, which also has a built-in graphic equalizer,
which one should use to EQ playbacks. Take a look at NU9N’s
Site for detailed information with regards equalizing playbacks. Make
sure that your Recording Level does not exceed 0 dB. Likewise, make
sure that your Playback level does not exceed 0dB, and that you do
not have to much ALC movement on the Playbacks
One tip with
reagrds Playbacks, make sure that your Processor/Compressor is OFF
Back off on the
RF Gain when making Recordings, cuts out the band noise
.JPG)
