Galaxy DX 2547 Clarifier Mod

Most operators that use sideband have unlocked clarifiers. Unlocking the clarifier means that the clarifier will change both the transmitter frequency as well as the receiver frequency. They will track together when this is done properly. There are many benefits to having this modification done. First, two operators having a conversation on sideband with unlocked clarifiers that are tuned to one another can be heard by others without having to retune on every transmission. Second, it two operators are unlocked, only one need tune to the other and they are both transmitting on the same frequency. Third, if the clarifier is unlocked and expanded, all the above is true and then the radio can tune between channels or even slide a full channel, depending on the radio's capabilities.

To unlock and expand the clarifier do the following:

  1. Make sure the radio isn't connected to a power source.
  2. Remove D68 a 1N4148 diode. (Fig. 1)
  3. Remove R113 a 47 ohm resistor. (Fig. 1)
  4. Remove R153 a 2.7K resistor. (Fig. 2)
  5. Jumper D38 a 1N4148 diode with a jumper wire. (Fig. 1)
  6. Jumper R114 a 2.2K resistor with a jumper wire. (Fig. 1)
  7. Run a wire from 8 volts constant to J9 pin F1. (Fig. 1)

Triple check your work before applying power to the radio. Once you're certain that everything has been properly changed, plug in the radio and turn it on for 15 to 20 minutes and proceed to the alignment step.

Now the radio needs to be put back to center slot. With the clarifier switch in the OFF position, adjust the following.

ITEM UNIT UNDER TEST SETTING ADJUST
POINT		 MEASUREMENT
AM Frequency Set the radio to CH 1 AM RX mode.
Connect frequency counter to TP3.		 L20 16.2700MHz ± 20Hz
USB Frequency Set the radio to CH 1 USB RX mode.
Connect frequency counter to TP3.		 L21 16.2725MHz ± 20Hz
LSB Frequency Set the radio to CH 1 LSB RX mode.
Connect frequency counter to TP3.		 L22 16.2675MHz ± 20Hz

Turn the clarifier ON and verify, with the clarifier at the 12 0'clock position, that the radio is on center slot. 26.9650. The clarifier will shift the transmitter and receiver frequency at least + 2.4KHz and - 6.3KHz. This makes it easy to pick up those operators on even frequencies. The clarifier becomes more sensitive once this modification has been made. Much to my surprise, it wasn't to difficult to tune in 5KHz down. Also, once you have set the clarifier down 5KHz, to go back up 5Khz, just switch the clarifier off. ©CBWI

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