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Galaxy DX-959 Mods | Radioaficion Ham Radio

Galaxy DX-959 Mods

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Galaxy DX-959 Mods
10kc Switch Modification
Clarifier (Unlock) Modification
Clarifier/Frequency Counter Realignment
Microphone Wiring Pinouts
Frequency Roadmap
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Galaxy CB Radio DX-959 Mods

PLL: RCI 8719

Modifiable -Can be expanded to include the full range of frequencies this radio is capable of from 26.695MHz up to 27.965MHz
Note: Additional channels can be acquired by "broad-banding" this radio. However, even though Galaxy has "hinted" information regarding the broad-banding procedure, it has yet to be tested.

Microphone Gain Modification:

The DX-959 has plenty of modulation to spare but it lies dormant as the factory settings "choke" it's true audio capability. This can be remedied, however!

Q39 is the modulation limiter for the DX-949 and DX-959. However, don't be foolish by removing the limiter. Why? The limiter is there for a reason! Removing the limiter altogether on the DX-959 will cause severe garbling in sideband mode. Instead, place a 1k resistor in series with the emitter leg of Q39. This used in conjunction with finding a satisfactory balance between adjusting VR16 along with the Mic Gain on the radio, and using a good amplified microphone will provide as much modulation as desired.

Many 959 owners report excellent results by just peaking VR16 and balancing their Mic Gain on the radio with an amplified microphone (without adding the resistor). All I did with my radio (no resistor) is peaked it just right with the screwdriver and now it's LOUD and PROUD. All without clipping the mod limiter. That's simply just a no, no with any radio!

Channel Expansion Modification

1.      First, remove power to (unplug) the radio. Remove the bottom chassis cover of the radio.

2.      Locate J33 near the left-front of the main board. It is partially hidden under the small PCBs just above it. This is the controller you will be working with.

3.      On J33, locate the wires going into the P5 (Yellow) & P6 (Gray) positions and note their colors. These are the main frequency control lines. Follow both to each end and cut each wire at a convenient spot where it will be easiest to work on them.

4.      Install an SPST switch between the gaps in each wire. Do not cross the wires. In other words, you want each switch in-line with each wire. This will effectively "open" or "close" each wire's circuit associated with the PLL. This provides the extra channels. Locate the switches anywhere you'd like as long as they are easily accessible. One option is to use any existing switch located on the front panel of the radio due to the fact that it is so cluttered with switches and knobs already.

5.      Replace the bottom cover of the radio.

Your radio should now be fully expanded to operate on the expanded frequencies. Here is a link to the roadmap for the above new frequencies.


~
Another option~
Is to "tap into" the P5 & P6 lines with a 4-wire telephone cord (or equivalent). The cord would then route through one of the factory holes in the back of the radio to the SPST switches mounted on a small project box on the other end. No cutting or drilling anywhere on the radio is required. E-mail me if anyone wants step-by-step instructions. Although this is a viable alternative, the trade-off is that some people might not like the fact that they have an external "remote control" box and cord for controlling the extra channels -something about their radio looking "obviously illegally modified". Whatever. If "Uncle Charlie" ever suspects that your radio is transmitting illegally they will find out anyway. Get it? Regardless, if the radio is to be used as either a base station or mobile, this method should definitely be considered and not overlooked. Besides, everyone who has seen my radio wired this way says it looks wicked.  ;o)   -Thanks, tac0meat for suggesting this idea!

~Update~

In light of the recent addition of
the 10kc switch mod, I elected to take the option above (4-wire telephone cord) one step further. Since the 10kc mod also requires a switch, I decided to add the new one to the project box as well. This gives complete control over all of the frequency mod functions in one handy control unit. Unfortunately, this also leaves the issue of what to do about the required three new wires. However, after a bit of brainstorming, I found the problem is easily solved courtesy of a 3 foot length of Cat 5e Twisted Pair computer network patch cable! These cables are readily available, and typically have 4 pairs (8 wires total inside one "cable") of the correct gauge wire. So yes, I had to de-solder and re-solder on both ends of the phone cord in order to swap out the old vs. new cables -but the effort was definitely worth it. The only remaining problem is the different colors of the new wires, but careful thought regarding the new different colors and their "old" equivalents... and voila! BTW, due to the slightly thicker new cable, I ended up having to ream out one of the existing holes in the back of the radio just a touch after all -can't tell, though. Oh well, I'm still very satisfied with the results, though.