TH-D7A TX band mod for US and Canada models -Allows TX 136 - 174 and 400 - 480

Click here for mods for the TH-D7E (European Model)

Although I have performed this modification on my own radio with no problems
noted, I take no responsibility in the accuracy of the procedure shown
below. If you do not feel comfortable working with small surface mount
components, you should not be performing this procedure.

1. Using Kenwoods program, download all saved settings from your radio. (All settings will be erased on power up after this mod)
2. Remove battery, antenna and freq/volume control knobs.
3. Loosen both fasteners from the antenna base and the freq/volume
control shaft.
4. Remove the four screws that secure the back of the radio.
5. Pull the top plastic piece with the Led's off the top of the radio.
6. Gently pull on the rubber gasket that goes around the top of the
 radio.
7. Pull the bottom of the radio appart gently.Note: There will still  be a ribbon cable connecting both parts (see picture). I removed
 the ribbon cable to make it easier to work on.

8. Pull the brown part of the ribbon cable connector upwards using
 your fingernail or small screwdriver. This will release the ribbon cable.

9. Locate the green wire. Under the green wire there are four small
 diodes in a neat row (they should have a miniature A on them if
 your eyesight is good). Using a soldering iron, remove the middle
 two diodes.

10.  Put the radio back together in the reverse order it was taken appart.

Modification Notes:
It has been suggested that modifications to the TH-D7a may somehow void the manufacturers free firmware update that is available. While I don't believe my modified transmitter will have any problems in getting its deserved firmware update, I did however save both diodes for future replacement if it ever becomes necessary. This may be a good idea if you were ever to want to "trade in" your radio to a store, or if warranty work is needed. (Just in case)


Mars Modification: 

There is another modification that can be done instead of the one above. It will have a smaller effect on the available TX frequencies. However this modification is easier to do and much easier to reverse.

Follow the same directions as above, but #8 is optional and probably not necessary. When you get to #9 just cut or remove the green wire. Do not remove any diodes. This mod will have the following effect on TX freq:

TX frequencies of 142.000 to 151.995 are possible
TX frequencies of 420.000 to 449.995 are possible

No change to RX freqs with either of these mods.


Diode configuration list - Lists all possible modifications to diodes

What are Kenwoods thoughts on self modifications?

KD6VYV
Comments, additions? Email walter@radiohound.com
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