Modifications for the Kenwood TH-28
Secret function manual of the KENWOOD TH-28e/48e
u>TH-28e/48e RX EXPANSION (ON)
Press PTT + VFO, then POWER ON.
New RX ranges TH28e after this modification:
VHF Band 136 - 174 Mhz (FM)
UHF Band 400 - 520 Mhz (FM)
TH48e:
UHF Band 400 - 470 Mhz (FM)
VHF Band 136 - 174 Mhz (FM)
TH28e Air Band Expansion
Press F key for 1 sec. Then press LOW key.
New RX ranges
108 - 118 Mhz (FM)
118 - 136 Mhz (AM)
TH28e 340 - 400 Mhz Expansion
Remove the diode D8 from the control unit. (FM mode only) With Air Band and 340 Mhz expansion, operating band can be changed:
_________ _________ __________
---->I AMATEUR I====I 340 Mhz I--->I AIR BAND I_____
I I_________I I_________I I__________I I
I___________________________________________________I
TH48e 340 MHZ & 900 MHZ EXPANSION
Remove the diode D8 from the control unit to cover 340 - 400 Mhz and 800 - 950 Mhz FM mode.
_________ _________ _________
--->I AMATEUR I--->I 340 Mhz I--->I 900 Mhz I_____
I I_________I I_________I I_________I I
I__________________________________________________I
TH-28e/48e TX EXPANSION
Remove the diode D10 from the control unit.
New TX ranges after this modification:
TH28e:
VHF Band 136.000 - 174.250 Mhz (FM)
TH48e:
UHF Band 400.000 - 470.000 Mhz (FM)
Note:
Manufacturer guarantees TX/RX specification only in amateur band. The above frequency range is for the microprocessor's range so that the receiver sensitivity or TX output power of expanded band may be reduced.
TH-48E TX/RX 432-438 Mhz LIMITED RANGE
Remove the diode D14 from the control unit.
TH28e/48e CROSS BAND REPEATER
Remove the diode D4 then press F key for 1 sec. and press 0 key.
TH-28a/e-48a/e FREQUENCY EXTENSION
Open the case and remove or add the destination chip diode D10, D11, D14 and D15 on the component side of the control unit.
(X53-340X-XX, X53-341X-XX)
The frequncy can then be extended as shown in the table 1 an 2 on page 3 and 4.(See the destination chip diode position drawing on the attached sheet.)
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