Alinco DX-70TH and DX-70T TX and RX MODS

Note: I pilfered this from:
Note 2: I added the expanded 45-60MHz function (Item 6D).

HF: Extended TX, open the RX up to 35Mhz and down to 30 Khz, Open the VHF side from 45-60 Mhz RX/TX. All can be done quickly by removing or changing a series SMD resistors located in the detachable front face panel. This mod is a little tricky to perform, since it uses surface mount devices.  I TAKE NO RESPONSIBILITY IF YOU BREAK YOUR RIG.  Alinco, further, in their mod sheet, warns that performing this mod incorrectly will NOT BE COVERED via warranty. Then again, this rig is 20+ years old.  So, good luck with warranty coverage.  Use a very fine point iron of about 15 or 20 watts max! Make sure it is grounded too.
  1. Disconnect power
  2. Disconnect antenna
  3. Remove control head, Disconnect control cable
  4. Remove 4 screws on back of control head,
  5. Remove (unsnap is more like it) the control head back panel.
  6. THE MOD: Once you have the back panel removed, and using the big VFO knob as your guide (circuit board facing you, LCD display not facing you). The VFO knob should be on the left side. On the right side, in the lower right hand corner, you should see 2 distinct columns of chip resistors.
    On the board, they are NOT labeled, but I will draw the diagram below to help you. You can't miss these because there are 5 chip resistors in the left-hand row, and the right-hand row has 7 chip resistors. Above both rows is a solder-pad.

    Several chip resistors will be soldered in, depending on the model of your rig, and a solder pad is jumpered. Here are the mods per Alinco:

    1. HF RX down to 30 Khz - remove the jumper M
    2. Beyond just Mars Mod - TX/RX everywhere remove both jumpers C and E
    3. HF RX up to 35 MHZ - solder a bridge across pad A (a solder blob will work)
    4. VHF expanded TX/RX 45 - 60MHz - solder a bridge across pad I (use a short wire)

    After performing the above mods, reassemble the unit. Here's what my rig looked like with the above mods:
  7. DONT FORGET to reset the microprocessor (with the radio off, hold the F button and simultaneously turn the power on. All memories are wiped out, but the new bands are opened.
I've tried all mods with my Alinco rig and can confirm they work. I am able to pick up business band communication in the 46 Mhz range (FM), and cordless phones in 46/49 range. It TX's everywhere now too.

I do not take responsibility if you perform this mod incorrectly, and I am not responsible for your operation practice if you choose to illegally transmit out of band.


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