Alinco DR1200T Full Band Modification

Step 1. Remove 2 screws located on top of cover.

Step 2. Loosen the 4 screws on both sides of top cover (do not remove).

Step 3. Remove top cover

Step 4. Locate Yellow wire Loop behind tuning Knob (this wire loops from

the control board mounted on front pannel).

Step 5. Cut loop and tape ends.

Step 6. Replace top cover.

Step 7. Reset radio (press 'F' and VCO/M keys together. While holding down keys

turn off and on Power). Factory settings will be restored however the new frequency

range will be from 132 to 173 MHz. Any memory will have to be reprogramed.

These insructions are from Alinco,

Note: I haven't tried or verified this, proceed at your own risk.

Alinco DR1200T Full Band Modification

This modification also works on the DR112 and DR110 radios. Frequency range

when applied:

130.000 - 169.995

340.000 - 379.995

870.000 - 889.995

ALINCO DR-1200 INTERMOD REDUCTION

CAUTION: THE FOLLOWING PROCEDURE INVOLVES DESOLDERING SMD

(SURFACE MOUNT DEVICES). IF YOU ARE NOT QUALIFIED TO WORK ON SMD

DEVICES OR DO NOT HAVE THE PROPER EQUIPMENT, DO NOT ATTEMPT THIS MOD!

SEEK PROFESSIONAL TECHNICAL ASSISTANCE.

THE ORIGINATOR OF THIS MODIFICATION IS NOT RESPONSIBLE FOR

ANY LOSS INVOLVING THE PERFORMANCE OF THIS MODIFICATION.

CAUTION: THIS RADIO EMPLOYS STATIC SENSITIVE DEVICES. SUITABLE MEANS SHOULD

BE EMPLOYED TO ASSURE A STATIC-FREE ENVIRONMENT PRIOR TO BEGINNING

WORK ON THIS RADIO.

1. REMOVE POWER AND ANTENNA FROM RIG

2 . REMOVE BOTTOM COVER

3. LOCATE C-19, LEFT SIDE FRONT OF BOARD (CLEARLY LABELED, NEAR Q3).

4. REMOVE C-19: SUCK UP THE SOLDER AND CAREFULLY PRY AWAY

FROM BOARD WHILE STILL WARM.

5. SAVE THE CAPACITOR IN CASE YOU GOT THE WRONG PART!

6. REASSEMBLE THE RADIO, NO RETUNING NECESSARY.

This capacitor connects D1 (back to back diodes) to the first IF line. D1 is supposed to be

a "limiter". Unknown why Alinco chose to put in such a limiter, as the integrated IF chip IC-1,

an MC3357, has a built- in limiter. Also, the Kenwood TM-231 which uses nearly the same

layout and circuit, doesn't have such a ciruit. While the intermod hasn't gone away entirely

(I'm not done with it yet!), it has diminished enough to make the rig usable on packet

AND voice now. ===============================================================================

Note: I haven't tried or verified this. proceed at your own risk.

Alinco mods to use mic connector for 9600 baud data

TRANSMITTER

Remove R31

Remove C40 and replace with one end free and other end reconnected to pin 7 of the VCO board.

Connect a jumper between the now free end of C40 and the hot end of C35.

The Mic input is now connected directly to the VCO.

RECEIVER

Disconnect the pink wire that goes to data output on the mic connector from the PCB

and reconnect it to pin 2 of the IF board connector.

This eliminates the low pass filtering on the discriminator. (Info from Alinco) ========================================================================

Note: I haven't tried or verified this, proceed at your own risk.