TROUBLESHOOTING CHART

Pilot Light fails to come on when power is switched on
Check to see that power cord is connected to wall receptacle.
Check Fuse.
Check pilot bulb.
Check for power at wall receptacle.
Check power cord for broken wire or unsoldered connection.
Check for faulty power switch.

Filaments fail to light but Pilot Light comes on
Check for burned out power tube. Filaments are in series and fail to light if even one only is burned out. If tubes are OK, check filament circuit for broken wire or bad solder connection.

Amplifier will not key when keying driver
Relay buzzes or chatters. Check to see that coax from the driver goes to connector marked Transmitter and not the one marked Antenna. This condition can arise also if the power from the driver is something less than 1 watt even if the coax is connected correctly. Unit will not key even with sufficient drive available and coax connected correctly.
Check the following. Check for voltage when keying driver at junction of R8. C17, C15, R7 and D4. This is point G on the schematic. See photo of Relay Board, Voltage measured should be approximately plus 3 volts DC with 31/2 watts of drive. Lack of voltage could be caused by a cold solder joint anywhere from the coax input to this point. Check Diodes D3 and D4 for short or open. Check voltages at all terminals of TR2 and TR3. See Voltage Chart. Replace faulty transistors if any. Check RY1 for open coil or cold solder joint. Check for bad function switch. Relay keys but no output from amplifier. Measure RF voltage at Point J on power amplifier PC Board (90 T) when keying driver. If present, skip to next section of Troubleshooting Chart. If no voltage is present. check coax from relay PC Board to Point J on power amplifier board. See Photo. Check all relay connections for both RY1 and RY2 for cold solder joints. If all connections are OK. relay could not be closing or points could be corroded or burned. It is possible if care is used to remove the plastic covers of the relays to burnish the contacts.

Pre-Amp does not work
The previous information pertaining to relays applies to this problem as well. RY2 does not key when Pre-Amp Switch is turned on. Check for broken wires from switch. This is easily checked as well as the operation of the switch. Measure the voltage from the ungrounded side of the switch to chassis ground. In the OFF position, the voltage is approximately plus 16 VDC. When the switch is turned on, the voltage will disappear as this point is grounded through the switch. If there is no voltage with the switch in the OFF position, check for a broken wire, bad solder joint or open RY2 coil. Relay operates but Pre-Amp does not amplify. Check voltages of TR1. Check for cold solder joints especially the eight connections of the four RF coils, L1, L2, L3, L4. They may not go through the board far enough. Check to see if D1 and D2 are shorted. Check all components in the Pre-Amp circuit.

No or low output from power amplifier
One or both 6LF6 tubes flat or burned out. Same as above with new tubes. Check to see Output Switch is in HI position. Check voltage at point B. It should be about plus 94 VDC with the output switch in the LOW position. If there is no voltage at this point at all, check for short to ground open R5 Resistor or shorted Zener Diodes D5 and D6. If the voltage is excessively high, one or both Zeners could be open. Measure voltage at Point L. If it is much over minus 17 volts, bias is probably not set correctly. See Section on Tube Replacement.

DANGER: Following measurements must be made with great care. Permanent injury or death can result from accidental contact between these points and ground.

Measure voltage at plate caps of 6LF6 tubes. If voltage is present, skip to next section of Troubleshooting chart. If high voltage is not present, move to Point N. If present at N, check Parasitic Chokes Z1 and Z2 for open circuit. If no voltage is present here, move to Point O. If voltage is present here, Plate Choke RFC1 is probably open. If there is no voltage at this point, move to Point A on power supply board (90 PS). If voltage is present, wire to bottom of RFC1 is broken or cold soldered. If there is no voltage at Point A, problem is in power supply board or power transformer. Check components BR1, C17 and C18. Check solder connections of all components including power supply transformer leads to PC Board (90 PS).

If all voltages are present but no output from amplifier
Check coax from loading capacitor to RYl for short or open circuit. Check load and tune capacitors for bent blades causing short. Check all connections for broken or bad solder joints. Check band switch for broken connections or bent contacts.
Check Coils L6 and L7 and all solder connections associated with coils.
Check coupling capacitor C10 for short or open.

Mode Switch does not switch in delay on SSB.
Check for faulty switch, broken or badly soldered wire from switch to PC Board and check solder connections of Relay Board of C16. Check C16 for short or low capacity.
Replace if faulty.

Meter does not read when transmitting but there is output from the amplifier.
Check for faulty meter.
Check all wiring for open or shorted connections.
Check following components on PC Board (90T), R15, R16, C21, C22 & D9.
Check wire and connections from C21 and Antenna Connector J2.
A rare problem that occurs sometimes and is very difficult to track down is the conductor material on a PC Board will crack. It is difficult to find and usually shows up as an intermittent problem. Flexing the PC Board will assist in locatinq the intermittent. This is caused by the loss of connection or snort to ground between components. This can be repaired by soldering a wire across the break in most cases. Loose hardware holding the boards to the chassis can also cause the same symptoms.