Turn off the radio.

Pull the channel knob off and behind it there is a diode covered in (usually) a yellow protective isolation tube.

Cut one leg of the diode.

Turn the radio back on.

Press Func then press and hold the Call button for a few seconds.

If the diode is not behind the channel knob it will be behind the board inside the radio in the same area, it is the only regular looking part , the rest will be those little surface mount chips.

This mod was sent to me by Douglas E. Roberts, thank you.

Here is the proper channel Mod. for the Magnum Delta Force that I did and it works!

Ok now soldering skills need to be very good on this job or radio will be trash.

1.Turn on power for a minimum 10 seconds then shut off and disconnect power

2.Remover cover (Speaker side).

3.Remover channel knob and locate D-555 diode which is the only thing behind knob.

4.Locate and remover 0-ohm resistor marked "000" (this resistor is a surface mount).

5.Locate and short out the CPU reset pads locate below and just to left of resistor 000.

6.Resistor and CPU pads are located on visible corner of front panel circuit board by frequency control switch.

7.Button back up and power it up.

8.Push Function and then push and hold Call for about 3 to 4 seconds and you'll be into 11 Meters

Now this Mod worked real good and you'll be able to switch bands by using the call button, it goes from A-J and frequency range from as low 25.165 at A to as high as 29.695 on J (11 Meter Band is on E), you'll need to push Function and Call each time you turn it on because it returns to defalt 28.000 MHz but it does remember the last channel you were on shown as frequency in the 11 Meter band

Deltaforce Variable power range modification

Derek Lindberg sent me this mod, thank you.

I have a new mod for the Magnum Delta Force, so here it is.

With the bottom cover off look for varible power control knob.

On the outer legs between the top and middle legs you will find a 2.2k resistor remove it.

This will give you a greater value between high and low power.

I have done this and it works great.

This mod was for the Magnum 357DX, but it should also work for the Deltaforce.

Basic expansion

The most common and simplest conversion is cutting the diode lead on the front panel CPU PC board.

You can see the diode location in the photo below.

After the diode is cut and before the power is applied to the radio, short out the two Reset Pads illustrated in the photo below.

The conversion is now complete.

Usage

To toggle to 10 & 11-Meter operation, momentarily press the CLAR/FUNC control, then hold the CALL button for 3 seconds and release, this will be required each time the radio is powered on until an 11-Meter frequency is programmed into memory.

The above diode conversion retains the three position STEP command in the 10-Meter only band, each time the step button is pressed, one of the digits on the LCD frequency display right of the decimal point flashes.

Either the UP/DOWN buttons on the microphone or the frequency selector on the front panel will change the digit from 0-9, only that digit will change under this command.

The next digit to the left will remain unchanged while in this mode.

The operator can select and change the 1KHz, 10KHz, or the 100KHz digit while it is flashing.

To exit the STEP command simply press the step button until there are no flashing digits or momentarily press the microphone PTT switch.

Full coverage expansion

The second conversion is the full coverage conversion.

The down side to this conversion is that the radio can't be toggled back to the 10-Meter only operation and none of the commands associated with this operation can be accessed.

The up side is the radio powers on with the last frequency used without the addition steps required in the first conversion you must decide which is best for your needs.

To perform the full coverage conversion a resistor must be added to the circuit traces shown in the photo below.

The diode need not be cut, but if it is already, it won't have any effect on this conversion.

The spacing of the pads are for a SMT 1/10 watt resistor the value required for this conversion is 47KOhms, good soldering skills are needed to perform this modification, the pads are delicate and will lift off the board with excessive heat so a low wattage small tipped iron is essential, if you choose to use a standard resistor, a 47K 1/8 Watt is preferred for it's small size, but a 1/4 Watt is OK.

It's recommended that the circuit traces be followed to other components already attached to them and the standard resistor be soldered to them at those points for added strength.

Mounting a standard resistor to the pads meant for the SMD part means the resistor will have to be mounted vertically and the additional stress in mobile operation could and most likely would damage these circuit traces over time with the vibration of the moving vehicle.

After the resistor is added and before the power is applied to the radio, short out the two Reset Pads illustrated in the photo below.

The conversion is now complete.

I found this mod info at The CB World Informer, unfortunatly I have lost the URL of the site.

Magnum 357DX Adjustment Locations

I found this mod on The Quack Shack forum.

Short description:

1.Turn on power for a minimum 10 seconds then shut off and disconnect power

2.Remove cover (Speaker side).

3.Locate the jumper pins as shown in picture, set the jumper to the required position.

4.Press the CPU reset button that is on the same PCB for 10 seconds.

5.Button back up and power it up.

Long (detailed) description:

Make sure the radio is off and disconnected from power. After selecting the desired frequency set up, press the CPU reset switch SW1 for 10 seconds.

MOVE THE SHORTING SHUNT TO THE DESIRED CONNECTION

The pic below gives a self explanitory overview of the connections and thier functions with the exception of a few notes that I will list here per connection.

CON 1: Default mode, all functions operate

CON 2: 10M and Expanded Mode. When you turn the radio on it defaults to 10M. For the Expanded Mode, press FUNC and CALL for 3 seconds. Repeat these steps to return to 10M.

CON 3: Expanded Mode Only. The frequency range is grouped in 10 bands of 40 channels each. (Letters A --J) Band "E" is CB. To switch bands QUICKLY press the CALL button. (DON"T HOLD IT DOWN)

CON 4: CB mode, operates on the regular CB frequencies of 26.965 -- 27.405MHz.

Expanded mode notes:

On the Channel Display, the small number 0 - 9 to the right of the band letter is the 1KHz freq display. For instance, lets say you're on 27.405 MHz. The Display will read 40 E5, which means you're on Channel 40, Band "E" and the "5" is the 1KHz position of 27.405.

In Expanded mode the RPT and SHIFT don't work.

I found this mod on The Quack Shack forum.

There are two different types of conversions that you can do to this radio.
The easiest conversion has a freq range of 26.065 -- 28.755 MHz. The "PROGRAMMABLE" mode gives you a range of 25.165 -- 30.105MHz.

CONVERSION VERSION 1
Remove jumper "A" from the channel board.

CONVERSION VERSION 2

1: Set the band selector to the "A" position.
2: Remove both jumpers "A" and "B" from the channel board. The Channel Display now displays letters "A" through "L" instead of a channel number.
3: Next carefully short the pins of jumper "A". Notice that each time you short the pins the Display goes to the next letter or frequency range. Do this until you have the desired frequency range for position "A".
4:Repeat these same steps for each of the 6 Band positions.
5: When you have completed the process, replace only jumper "B" to lock them in memory.
6: Leave jumper "A" off for the full frequency conversion.

I found this mod on The Quack Shack forum.

The radio comes with these jumpers already in the #1 and #4 positions and it is 10 meters only at this point.

Frequency Range Mod (25.165 -- 30.555MHz)

1: Power up the radio for 20 seconds then disconnect from power.
2: Set the band selector to position "A"
3: With a 2 short wires, jump the pins of JP2 and JP4 ( JP1 and JP3 = off) The channel display now shows the letters "A" - "L".
4: With another wire, temporarily short the pins of JP1. You will notice the display moves to the next band letter each time you short JP1. Do this until you have the desired frequency for band "A". Continue to repeat these steps until you have moved through all 8 band positions, setting them up as you like.
5: Once you have finished the programming, move the jumpers to this order to lock them in memory:
JP1 = ON JP2 = OFF JP3 = OFF JP4 = ON

Actually, from what I've seen so far, the above mod is not correct, but it's the only one available to most.
What you have to do is the second mod, basically you have to select what frequency range you desire, and set the letters up for that range.
Set the radio to "A" then pick "A" if you want your bands to start there, and so on for each letter.
You can make any letter whatever you want it to be. But I have not yet been able to get the mod to work unless we programmed in all the letters first.
Then you merely remove JP 4 when you are done and move JP2 to JP1 position.

TwelveVolt

Frequency counter 6 digit display mod

Removing JP4 makes this unit show all 6 digits on all modes, as out of the box it only shows 5 digits unless on SSB, which shows all 6 digits.