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Note:
No liability in any form will be accepted in respect of recordings made using the RU8200
option.
Lack of SSB reception - resonator replacement
We have received two reports of lack of SSB reception with the AR8600 series, either USB or
LSB failure. On both occasions, the problem has been traced to failure of the SSB resonator
with simple replacement clearing the fault.
AR8600 (MK2) USB and LSB resonator replacement.
Remove top and bottom case halves (16 screws).
Remove top chassis cover (6 screws – 3 down each side), unclip speaker wire).
Remove bottom chassis cover (3 black, threaded screws in centre of board from top and 6 screws
from bottom).
Looking from the front, top of the AR8600, the SSB resonators are located in the front, right
hand corner of the set.
The board is marked;
X3 LSB - This should be 453.5kHz (marked 453)
X4 USB/CW - This should be 456.5kHz (marked 456).
Replacement is simply by de-soldering the device and fitting a new one.
If one has stopped oscillating, before replacing it, check that none of the surrounding devices
have any dry or failed joints.
In practice, alignment of these devices will not have been set up too critically and will probably
not require much alignment.
They can be aligned if necessary.
According to the service manual;
For LSB, with the receiver set to 5.000MHz, adjust VC1 and VC2 for a BFO output of
453.5kHz +/- 50Hz (measured at TP105-1, labelled BFO on board).
For USB, adjust VC3 and VC4 for 456.5kHz +/- 50Hz.
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