Flex 6600M Low TX Gain

FotisGR

Hi, a few days ago I bought a 6600M. This radio seems to have low TX gain. Setting my input sound level between -10 and 0 as suggested by the manual, the output power does not exceed 10 - 20W, although the OUT power is set to 100W out. At first I thought it was a matter of indications but connecting my amplifier ACOM 2000A, I found that it can not be driven properly due to low output power from 6600M. My amplifier to be properly driven and the 6600M to transmit output at about 75W-100W, my sound level input must be permanently in the red zone, well above 0, and my Audio TX sound is aggressive and slightly distorted. With the PROC ON, things improved enough but I still have to be in the red zone of audio input level. I don't know what is wrong, the DEXP is OFF to zero and the TX BW filter is 80-3100. No SWR , no voltage drop from Diamond PSU. The problem is still the same at all bands from 160-10m. I tried another microphone (my Electrovoice RE27 in to the Balanced input without any improvement. I have enough transceivers in my shack like the Icom 775 and Icom 7851 and they can drive easily my amplifier with 50W out with minimum transceiver's ALC . Who can help me?

David Decoons, wo2x

The processor should be on and in normal position for normal rag chew.

People find having a small preamp between RE-27 and radio helps to get more consistent audio drive. I have tried my RE-27ND straight into the radio and found not enough audio drive. I use the W2IHY EQ equipment and do not use the internal EQ.

With radio set to tune mode, how much power is required to get to your desired output? Also check your voltage at the radio during TX. I have my power supply set to 14.4 volts on TX. You can use a program such as FRStack to measure voltage at radio.

How are you measuring output power? The meter in SmartSDR is not a peak reading meter.

Dave wo2x

K0FLY

David has some good suggestions, especially the tune power test and voltage at the radio.

I had the same problem, my S-Line had more talk power than my 6500. I originally had my TX EQ sliders set at zero and below, and had to run my mic gain into the red to get good power out. I found that with the processor set to normal, increasing the internal TX EQ sliders increased the SSB TX gain. Try turning up the TX EQ sliders and lowering the mic level. I found that when I started see a some movement on the SSDR compression meter with the mic input set to around -10 the output power was good with great audio reports. I found that after those adjustments I had to reduce the TX power slider to keep from over driving the old PA.

It took me several weeks to figure this out, some of my friends told me to get a real radio. They dont say that any more.

Gayle k0FLY