Andrew
Yes the power supply amps does peak with the modulation.
I do have a generator.? I have used it when setting tx gain and output power for vhf/uhf.
Tommy
Hi Tommy,
Is it still drawing 20 amp from the power supply?
When you are speak into the mic,? do you have an audio dig generator?
KR
Andrew
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On 27 Jan 2025, 22:09, at 22:09, "Tommy Wooten via " <kf4rwg=[email protected]> wrote:
>Andrew,
>I have done some more measurements as you recommended.? I removed the
>PA
>board and attached a connector to the output of L305 separated from the
>rx/tx relay and HPF.? I have attached photos of the input and output
>voltages set at 10M USB with voice into the microphone.? These voltages
>are
>much less than what you said they should be.? The problem must be up
>stream
>from the PA FETs.
>The oscilloscope was set at 50 millivolt per div in both photos.? The
>voltage was lower at the output of L305.!?? But measured about 6 watts
>on
>the external power meter into a dummy load.
>
>The vhf/uhf works well so the driver is working.
>
>Thanks for your help.
>Tommy
>
>
>
>On Sun, Jan 26, 2025 at 10:55?AM Andrew Lenton via <a=
>[email protected]> wrote:
>
>> This is a very hard radio to work on, as you cannot easily get to the
>PA
>> board the way it is mounted and soldered into the pa driver board
>>
>>
>>
>> I would remove the PA board, replace L305, for starters while it is
>out
>> you can inspect the components one by one.
>>
>>
>>
>> This unit does not lend itself to test and measurements, as all you
>can do
>> is prod the rear.
>>
>>
>>
>> All 12V HF PA stages have an impedance in the milli Ohms 0.4 to? 0.6
>ohms,
>> as it draws 20A, or so, the output transformer has to match 0.6 Ohms
>to a
>> 50 Ohm, so it needs to step up the voltage.
>>
>>
>>
>> The problem is it would be nice to lift L306 and put your Watt meter
>in
>> there, but you have to rip the PA board out then put it back together
>to
>> make the measurement, so impractical
>>
>>
>>
>> To protect the PA the is a coupler to control power and to protect
>the PA
>> against hi SWR, however, if no power is getting past the coupler you
>will
>> have full power 24/7
>>
>>
>>
>> There could be a fault here:
>>
>>
>>
>>
>>
>> But only you can trace, so measure i/p to L305, you will get a
>voltage,
>> the out put will be higher at 100 Watts 50 Ohm the voltage will be
>70.7V
>> RMS, so PTP on a scope 200V if you are not getting this on the O/P
>then
>> move back to the I/P you should get 13.8 V? to 40V PTP. I have one of
>these
>> in bits working before I box it back together I will make some
>measurements
>> and send back to you. as the PA in not loaded with 50 OHM, the
>voltage can
>> rise too high
>>
>> You need to set a voltage on Ref or FOR to knock the power back to a
>few
>> Watts then you can uses CW and safely trace you signal.
>>
>>
>>
>>
>>
>> KR
>>
>>
>>
>> Andrew G8UUG
>>
>>
>>
>>
>>
>>
>>
>> -----Original Message-----
>> From: [email protected] <[email protected]> On Behalf Of Andrew Lenton
>> Sent: 26 January 2025 10:00
>> To: [email protected]
>> Subject: Re: [ic7000] IC7000 no HF Transmit
>>
>>
>>
>> This is a very hard radio to work on, as you can not easily get to
>the PA
>> board the way it is soldered into the pa driver.
>>
>>
>>
>> I would remove the PA board, replace L305, for starters while it is
>out
>> you can inspect the components one by one.
>>
>>
>>
>> This unit does not lend itself to test and measurements, as all you
>can do
>> is prod the rear.
>>
>>
>>
>> All HF PA stages have an impedance in the mOhms .1 .2 ohms as
>thet6drsw
>> 20A, the out put transformer has to match .1 of an ohm to 50, so it
>needs
>> to step up the voltage.
>>
>>
>>
>> KR
>>
>>
>>
>> Andrew
>>
>>
>>
>> I have a wiring unit, I can make some measurements for you
>>
>>
>>
>> ?Get BlueMail for Android ?
>>
>>
>>
>> On 26 Jan 2025, 01:32, at 01:32, "Tommy Wooten via " <
>> kf4rwg=[email protected]> wrote:
>>
>> >Bob, Thanks for the encouragement
>>
>> >
>>
>> >I have considered all of the suggestions for troubleshooting the
>>
>> >problem I have with the IC7000.? I have tried to trace the HF RF
>path
>>
>> >with an oscilloscope from where the signal comes through the cable
>from
>>
>> >the main board to the PA board.? I have traced the signal and
>inspect
>>
>> >all components through to the output at ant1.? The signal seems to
>>
>> >loose its punch where the PA FETs combine into the L305 transformer.
>>
>> >The bias setting of the PA FETs seem to be correct.? After the
>signal
>>
>> >reaches the rx/rx relay it passes through the selected HPF where it
>>
>> >reaches ant1.? The resulting signal is only a few milliwatts.? I
>have
>>
>> >tried to keep the setting in SSB and I see modulation when speaking
>>
>> >into the microphone.
>>
>> >I know it is difficult to troubleshoot the issue remotely but I
>>
>> >appreciate any and all ideas.
>>
>> >Thanks
>>
>> >Tommy. KF4RWG
>>
>> >
>>
>> >
>>
>> >
>>
>> >On Sat, Jan 25, 2025 at 6:31?PM Bob via <W4JFABob=
>>
>> >[email protected]> wrote:
>>
>> >
>>
>> >> Well this is #30 then. That's OK because when the rest of us have
>>
>> >this
>>
>> >> problem we'll appreciate every one of these replies.
>>
>> >> Keep on writin' you guys.
>>
>> >> Bob W4JFA
>>
>> >>
>>
>> >> On Thu, Jan 23, 2025 at 4:40?PM Geoff via <vk3zgw=
>>
>> >> [email protected]> wrote:
>>
>> >>
>>
>> >>> Forgive me if this has been mentioned before but as this is the
>29th
>>
>> >>> reply I haven't gone back and read everything.
>>
>> >>>
>>
>> >>> I always go first to where the effect of a fault is obvious
>without
>>
>> >any
>>
>> >>> ambiguity, in this case the rf output ie Ant 1 connector, working
>>
>> >back to
>>
>> >>> eliminate ALL the stages involved, including in this case the
>SO32
>>
>> >jack.
>>
>> >>>
>>
>> >>> Good luck.
>>
>> >>>
>>
>> >>> Geoff
>>
>> >>> VK3ZGW
>>
>> >>>
>>
>> >>>
>>
>> >>
>>
>> >>
>>
>> >
>>
>> >
>>
>> >
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
>
