TH-D7A/E DIODE CONFIGURATIONS:

DIODES D508 D507 D503 D502

D502 REMOVAL IS SAME AS CUTTING GREEN JUMPER WIRE (W500)

X=Absent O=Present

 DIODES
 RX RX TX TX Default RX RX TX TX Default

2m Offset

70cm Offset

Tone 1750

Skycommand & Remote

VHF Narrow
REMARKS / 118-136MHZ

OXXX
136 174 136 174 144 400 480 400 480 430

 +/-5.7

+/-10

 ?

?

?
CHINA / N

XOOO
144 146 144 146 144 430 440 430 440 430

.6

 1.6, -7.6

Yes 

No

Yes*
EUROPE GENERAL / N

XOOX
136 174 136 174 144 400 480 400 480 430

.6

1.6, -7.6

 Yes

No

Yes*
EUROPE EXPANDED RECEPT./Y

XOXX
136 174 144 146 144 400 480 430 440 430

.6

4.6, -7.6

?

?
EUROPE EX. REC. UK/Y

XOXO
136 174 144 146 144 400 480 432 438 432

.6

 1.6

?

?
DENMARK/N

XXOO
136 174 144 146 144 400 480 432 438 432

.6

 1.6

 ?

?

?
DENMARK EXPANDED REC./Y

XXXO
144 146 144 146 144 430 440 430 440 430

.6

 5

?

?
TAIWAN/N

OOOO
136 174 144 148 144 400 480 430 450 440

 .6

5

No 

Yes

No
USA - CANADA/Y

OOOX
136 174 142 152 144 400 480 420 450 440

.6

No 

Yes

No
USA - CANADA MARS MOD/Y

OXXO
136 174 136 174 144  400 480 400 480 440

.6

 5

No 

Yes

No
USA-CANADA EXPAND TX +/Y

OXOX
136 174 142 152 144 400 480 420 450 440

.6

 5

No 

Yes

No
USA-CANADA MARS MOD +/Y

OXOO
136 174 144 148 144 400 480 430 450 440

.6

 5

No 

 Yes

No
USA-CANADA ?????/Y

OOXO
144 148 144 148 144 430 440 430 440 430

No

 5

No 

No

No
OVERSEAS GENERAL /N

OOXX
136 174 136 174 144 400 480 400 480 430

No

5

No 

No

No
OVERSEAS GEN. EXPAND TX/Y

XXOX
136 174 144 148 144 400 480 430 440 430

.6

5

 No

No

No
AUSTRALIA/Y

*TH-D7E Hardware Required for this function

The above changes to diode configurations can change a TH-D7A to a TH-D7E or vice-versa.

(Note: In my opinion, surgery on your radio may bust it, but only if you screw up. If you are a screw up, then surgery on your radio will probably bust it.)

However, Bob WB4APR writes:


Here is what I have gathered from a varitey of sources. This is at your
OWN RISK. Surgery on your radio will probably bust it and make it out of
warranty. But if you must tinker, here is what some people have figured
out...

Compare this to previous posts, there may be minor differences...

In general, the TH-D7A/E can be modified to all configurations.... But
the hardware is different between D7E and D7A because the UHF SAW
filter frequency is different and the narrow deviation filter are
different.

The D7A uses a 438-450 SAW filter for UHF and wide band LC filter
for 400-438 and 450-480MHz.

The D7E uses a 430-440 SAW filter for UHF and wide band LC filter
for 400-430 and 440-480MHz.

Skycommand and Remote access are only in the USA modes.
The Narrow deviation circuit is only in the TH-D7E hardware.

If you want to modify the TH-D7E to the USA type, and you want to use
UHF, you have to replace the SAW filter or the radio becomes deaf around
430-435MHz. But you DO get Skycommand and Remote Access in exchange for
deaf 430-435MHz.

If you want to modify the TH-D7A to a non USA type, and you want to use
UHF band, you have to replace the SAW filter. Otherwise, the radio
becomes deaf around 445-450MHz. You can use the 1750 tone burst and you
will see the VHF narrow menu (but it does not switch to narrow, since the
hardware is not there).

de WB4APR, Bob