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- MODIFYING THE TR2300 FOR QRO
- ============================
-
- 1. Remove the uppermost PCB (speaker grille side) by unscrewing the 6 PCB
- mounting screws. The PA and PCB should now be visible (X56-1280-00).
- Don't forget the PA heatsink screw.
-
- 2. Remove the connections to the PCB, removing the orange and grey leads,
- the local oscillator (LT,E), the aerial lead (P.O. and E), and the 2 PCB
- connectors.
-
- 3. Desolder the P.A. transistor (2SC2329), and replace it with a SD1127 (was
- obtainable from MODULAR ELECTRONICS, BOGNOR 0243-823603, price approx 4).
- Please note that the lead configuration is different.
- First put a sleeve over the base of the new transistor, then follow the
- orientation of the transistor according to the information sheet supplied
- with it. Make sure that the heatsink is placed in position before
- soldering the transistor into place.
-
- 4. Replace all screws securely.
-
- 5. Replace all leads correctly and carefully.
-
- 6. The mod is now complete except for the HI/LO power switching. Locate and
- remove the BLUE, WHITE, ORANGE and the PURPLE leads from the switch at
- the rear. The switch wiring contacts should now be free. Resolder the
- leads according to the diagram.
-
- 7. Solder a wire carefully on to the top of VR2 slider. NOTE: Take care to
- avoid damaging the pot in the process. Solder the free end of the wire to
- the switch as indicated.
-
- 8. You may breathe again........the mod is completed.
-
- SETTING UP
- ----------
- 1. Connect a dummy load and SWR bridge, and adjust TC4 TC3 and TC2 for
- maximum output. repeat this several times, and then DO NOT touch again.
-
- 2. Set switch to 1 or 2 (QRP) and adjust the low power to 1 watt using VR2.
- This must be done accurately if the unit is to be used with the Kenwood
- linear to avoid overdriving it.
-
- 3. The rig is now ready for use:
-
- WIRING TO THE SWITCH
- ~~~~~~~~~~~~~~~~~~~~
-
- f
- r
- o
- BLACK (leave on) m
- | vr2
- __|_______________|_____________
- - - - -
- - - - -
- --|---------------|--|----------
- p w b
- u h l
- r i u
- p t e ORANGE - insulate end
- l e
- e
- Switch positions:
- A. Low power
- B. Low power + light
- C. High power
-
- With acknowledgement to G8TYJ who designed the original mod.
-
- Rick G1AUH @ GB7FCI
-
-