Batboard

4-crime wrote:Hi, I was wondering if someone could help. when My xts5000 UHF conventional transmits it sounds almost like an echo on the recieving radio. Is there any way to change this?

9.2 Analog Mode of Operation
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When the radio is receiving, the signal comes from the antenna connector to the RF board, passes through
the RX/TX switch and the receiver front end. The signal is then filtered, amplified, and mixed with
the first local-oscillator signal generated by the voltage-controlled oscillator (VCO).
The resulting intermediate frequency (IF) signal is fed to the IF circuitry, where it is again filtered and amplified.
This amplified signal is passed to the digital back-end IC, where it is mixed with the second local oscillator to
create the second IF at 450 kHz. It is then converted to a digital bit stream and mixed a third time to produce a
baseband signal. This signal is passed to the vocoder board through a current-driven differential output.
On the vocoder board, the digital- signal-processor-support IC digitally filters and discriminates the
signal, and passes it to the digital-signal processor (DSP). The DSP decodes the information in the
signal and identifies the appropriate destination for it. For a voice signal, the DSP will route the
digital voice data to the DSP-support IC for conversion to an analog signal. The DSP-support IC
will then present the signal to the audio power amplifier, which drives the speaker. For signalling
information, the DSP will decode the message and pass it to the microcontrol unit.
When the radio is transmitting, microphone audio is passed from the audio power amplifier
(PA) to the DSP-support IC, where the signal is digitized. The DSP-support IC passes digital
data to the DSP, where pre-emphasis and lowpass (splatter) filtering are done. The DSP returns
this signal to the DSP-support IC, where it is reconverted into an analog signal and scaled for
application to the voltage-controlled oscillator as a modulation signal.
Transmitted signalling information is accepted by the DSP from the microcontrol unit, coded
appropriately, and passed to the DSP-support IC, which handles it the same as a voice signal. Modulation
information is passed to the synthesizer along the modulation line. A modulated carrier is provided
to the RF PA, which transmits the signal under dynamic power control.