Hello Group:
I have a sick FT1000D radio. All works fine except for transmitting on
the 40m band in any selected mode.
I would appreciate if someone can share their insight and help me in
troubleshooting the cause of this problem.
When I key the transmitter in CW mode, there is no indicated output on
my external watt meter nor the radio's PO meter position. With the Ic
meter position selected, varying the DRIVE control causes the amount of
meter deflection to also vary in direct proportion. With ALC meter
position selected, the DRIVE control can cause deflection to vary from
zero to approximately 30 on the VCC scale. Do these symptoms indicate
that the drivers and the PA are operating at 7 MHz?
I believe that the fact that reception appears normal when on 40m rules
out a faulty VCO circuit.
There were several cold solder joints found within the 40m channel
(LPF4) on the Low Pass Filter assembly and they were repaired more than
a year ago. With only an ohmmeter available here, I have checked
continuity and switching action of the input/output relays for the LPF4
channel; appears to be normal operation.
I am now leaning toward a popped open capacitor within the 40m LPF
circuit only if I can first prove that 40m rf is present at the input of
the LPF assembly.
Any ideas on proving that 40m RF is reaching the LPF assembly would be
welcomed.
Thanks and 73.
de ~ Vince ~
WA2RSX IOTA NA-026
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