MFJ-1278 & MFJ-1278T Fast-Start Manual
13
TXDIDDLE is defaulted to the ON setting to reflect the increased efficiency. However there are a
number of TNCs on the market which purport to be AX.25 compatible but do not recognize valid
AX.25 packets preceded by the TXDIDDLE keyup technique. You may recognize the need to set
TXDIDDLE OFF if it appears that the Station you're working is unable to successfully receive your
packets despite your adequate signal.
This failure of some TNCs to receive TXDIDDLEd packets may be a result of some Software carrier-
detect schemes. All TAPR and derivative TNCs utilizing hardware-generated carrier-detect receive
both TXDIDDLEd and non-TXDIDDLEd packets with equal efficiency.
Note that when TXDIDDLE is OFF, TXDELAYC is irrelevant! Therefore, the actual TXDELAY yielded
when TXDIDDLE is OFF is equal to TXDELAY × 100 ms plus any AXDELAY time.
