Dishtronix, Inc.
Dx2400l1 instruction manual rev00.doc 06-10-18 5.14
Page 30/44
5.
Advance the ALC ADJ control until the amplifier power output just dips the slightest
noticeable amount.
6.
Note the transmitter drive control setting. You should not require more drive than this on
any band, if your transceiver is modern and correctly designed to put the same power
output on all bands for the given position of the drive control.
When operating SSB, speak into the microphone in a normal voice. The front panel ALC
indicator may flicker or pulse, or come on completely. This is perfectly normal. Speech that
sounds choppy or compression limited is an indication of too heavy of ALC setting.
Too high of an ALC setting may cause the transmitter to “pump” or surge in power as the ALC
tries to react to clamp the output level. Do not try to control the transmitter output with the ALC.
Reduce the exciter drive instead to run at lower power. Remember the function of the ALC is to
keep the amplifier from saturating and overdriving. When the power output is below the
threshold level set by the rear panel ALC adjust control, ALC should have NO effect on the
exciter!
3.9.4
ALC Irregularities
If you experience erratic or irregular performance with the ALC line connected, you may need to
experiment with different grounding. Try using a shielded cable with one end of the shield
grounded to the amplifier, or the transmitter (but not both!) Try routing the cable away from
antenna and other leads, or wrap it on ferrite cores, etc. The amplifier has been carefully designed
to operate in a RF environment, but each installation is different. Be certain that you have
properly grounded your equipment and not “daisy chained” the grounds together in series. Refer
to the installation section for more details.
Disconnect the ALC line only as a last resort! Be very careful not to overdrive the amplifier on
CW or voice peaks! Dishtronix manufactures the DWM-2104A, a wonderful variable delay peak
reading wattmeter that is perfect for monitoring your amplifier in addition to the front panel
display.
3.10 Protection
Features
As mentioned in the ALC section, the first level of protection is the ALC SWR foldback feature.
In the event that reflected power exceeds 200W, the ALC action attempts to reduce transmitter
power until the reflected level is below 200W.
Additionally, the amplifier has several levels of circuitry to protect the RF power transistors. The
protection features are:
1.
Overdrive detector circuit.
2.
Overdrive protection circuit
3.
Internal SWR protection circuit.
4.
Internal Module over current protection circuit.
5.
Over temperature detector circuit.
6.
Power supply under voltage detect circuit.
7.
Power supply over voltage detect circuit.
8.
Combiner unbalance (PA module failure).
9.
PIN diode T/R circuit failure (optional).
Summary of Contents for DX2400L1
Page 11: ...Dishtronix Inc Dx2400l1 instruction manual rev00 doc 06 10 18 5 14 Page 11 44 2 INSTALLATION...
Page 19: ...Dishtronix Inc Dx2400l1 instruction manual rev00 doc 06 10 18 5 14 Page 19 44 3 OPERATION...
Page 41: ...Dishtronix Inc Dx2400l1 instruction manual rev00 doc 06 10 18 5 14 Page 41 44 5 SERVICE...
Page 44: ...Dishtronix Inc Dx2400l1 instruction manual rev00 doc 06 10 18 5 14 Page 44 44 NOTES...