Vertex Standard FT-1000MP manual Microphone Tone Selection, RF Speech Processor, Class-A Operation

OPERATION

TRANSMITTING

Microphone Tone Selection

Before setting up the speech processor, set the selector switch on the rear of the MH-31B8Dmicrophone (supplied) for the desired tone characteristic. The “2” setting suppresses low frequencies, providing more “pile-up punch” for DX operating. The “1” setting in- creases the bass response, important for maximum intelligibility when speaking in a language rich in vowel sounds (such as Japanese).

RF Speech Processor

Once the proper MIC control setting has been deter- mined, you can activate the RF speech processor to in- crease the average power of your transmitted signal.

rFirst set the METER selector to the “ALC” (Auto- matic Level Control) position, and ensure the level is within the red zone while speaking into the mi- crophone.

rNext set the METER selector to the

“COMP”(speech processor compression) position, and press the [PROC] button (at the left end of the row of buttons along the bottom) so that its red LED lights.

r Now while speaking into the micro- phone, adjust the PROC control for

a compression level of 5 to 10 dB on the COMP scale of the meter (the second scale from the bottom). If you have the monitor activated,

you will be able to hear the effect of the compres- sion on your signal. In any case, we do not recom- mend higher compression settings, as your signal will actually become less readable. For the purposes of making accurate adjustments, the long utterance of the word “Four” usually provides a stable, full voice waveform, ideal for setup of the RF speech pro- cessor.

rFinally, move the METER selector back to the “PO” position, and (without touching the MIC control set- ting) adjust the RF PWR control for the desired power output on voice peaks.

Class-A Operation

A unique feature of the MARK-VFT-1000MPis the capability to operate SSB in Class A. Switching to Class

Ayields an ultra-linear transmitted signal, with intermodulation distortion products significantly better than possible with a typical Class AB2 transmitter de- sign.

Because Class A involves a total current dissipa- tion much greater than utilized for Class AB, to which you’re probably accustomed, maximum power output during Class A is limited to 75 Watts as indicated on the PO meter.

To enable this feature, press the orange [CLASS-A] switch (located below and

to the left of the Main Tun- ing dial) while operating ei-

ther in USB or LSB. During

Class-A operation, the PO meter will indicate up to 75 Watts of power output, while the IC meter will show a no- modulation (constant) current of approximately 10 Amps.

Although the full advantage of Class-A operation will be compromised somewhat when a (non-Class-A) linear amplifier is used, the very clean drive power from the MARK-VFT-1000MPwill, nonetheless, provide a significant improvement in overall signal quality.

Carrier Point Offset

This feature allows shifting the carrier point IF pass- band (and hence the RF passband as well) of your transmitted signal in the SSB mode, to customize your signal for your own voice characteristics.

Seven individual carrier settings can be user-ad- justed:

USB Carrier (Tx & Rx) - adjustable from –200 ~ +500 Hz.

LSB Carrier (Tx & Rx) - adjustable from –200 ~ +500 Hz.

Processor Carrier (USB & LSB) - adjustable from –200 ~ +500 Hz.

AM Carrier - adjustable ±3000 Hz.

To display and adjust the various carrier settings, see menu selection 8-9. With the offset displayed, you can adjust it throughout the ranges shown above A minus sign indicates the offset is closer to the carrier (low-frequency speech emphasized). You can transmit during carrier display and adjustment.

Of course, you can adjust the offset by trial-and- error on the air, but it is better to use the built-in monitor circuit or a monitor receiver, in which you can hear the effect yourself. Otherwise, we recom- mend starting with +0.10 (+100 Hz) offset initially, to add some “crispness” to your processed speech.

MARK-V FT-1000MP Operating Manual page 53