TR-7850 RF LED Meter                       7-29-81


The RF LED meter may show reduced output after continuous transmission, while output actually remains constant.  Changing components on the final unit will correct this problem.  This change applies to units before serial number 201XXXX.

Procedure:

1.   Remove the top cover (four screws), and unplug the speaker.

2.   Remove the bottom cover (four screws).

3.   Remove four scress holding the heatsink and swing the sink down.

4.   Without changing coil spacing, desolder L6 which connects from         the ANT pad aon the final unit to the PL-259, at the final unit.

5.   Remove five screws holding the final unit pcb X45-1180-10, one         screw holding Q6 2SD880, and two screws holding the final hybrid       module Q1, M57726.

6.   Change the following parts:

     C15  1pf to 2pf     (CC45CH1H020C)
     D3   1N60 to 1S1587 (V11-0370-05)
     R8   820 ohm to 1.2K (RD14CD2E122J)

7.   Insure adequate thermal compound on Q1 and Q6, and that the mica
     washer is correctly positioned under Q6.  Reverse steps 5 and 4        to partially assemble.

8.   Cable-up power and a dummy load.  Readjust VR1 on the final unit       at 147.000 MHz, high power setting for 5 LED's ON.  Switch to low      power and verify 3 LEDs ON.

9.   Remove power from the unit and complete reassebly by reversing         steps 3, 2, and 1.

Note installation time for this procedure is 1/2 hour or less.

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SB-860

Memory Channel 7 Indicator Erratic                           4-14-82


When Memory Channel 7 is selected, the LED may fail to indicate the number  7, althought freqeuncy is correctly recalled and all other operations are normal.  Cause is incorrect voltage level at Q16 and Q17, and is related to individual differences between these IC's.  Correction is by changing one resistor value on the Control Unit.

On the Control unit X53-1180-xx, replace R38 from 3.9K to 1.8K.  No
adjustments are required.

This change should only be performed as necessary, and applies to units before serial number 205xxxx ONLY!

Installation time for this procedure is 1/2 hour or less.

PORTED AND REALIGNED FROM PC TO AMIGA FORMAT BY BOB G0LBQ - N6XDI.