[1000mp] Frozen SWR

[Tod Olson]

Gentlemen:

Let me begin by stating that the problem has been solved and apologizing
for incomplete testing on my part which caused me to write an appeal for
suggestions prematurely.

The problem was ³pilot² or ³operator² error. I operate a rather complex
SO2R station where all of the antennas are distributed correctly to each
of the radios as  a function of the frequency the radio is operating on.
When one changes bands on either radio the correct antenna for the band is
routed to the radio automatically by circuits that decode the band and
select the correct relays in a relay matrix to activate. Naturally, there
are protective circuits to prevent both radios being able to access the
same antenna at the same time or operate on the same band at the same
time. 

Somehow, someone [we know who the someone was ] manually selected the band
for the Œfailing¹ FT1000MP and bypassed the normal auto-band selection for
that radio. That meant that the antenna going to that radio was the
manually selected one, not the auto-selected one. The result was the SWR
was more than 3:1 on every band but one and the good band was never one
that I checked when testing. As a result the radio very correctly turned
down the power.  Once my early morning [ 6:00 AM Sunday morning here in
Idaho ] testing of everything from the antenna to the radio was completed
I had found the culprit [me] and corrected his stupid error. At various
times in the process I had suspected many different things were failing;
bandpass filters, relay selection matrices, relays, antennas, etc. I bring
that up because I have found ‹ especially as I grow older, that careful
testing of things before taking action can often save many fruitless hours
of unneeded repair or additional testing of components that are not really
failing.

At this point I don¹t try to fix circuits or equipment until I am
absolutely sure that circuit or equipment is truly causing bad things.

The good things that came out of my inquiry are the references that were
provided by Ron, W8GUS, Bill, WD8ARZ and Lance, WN0L. I will be following
up on your references to add them to my collection of FT1000MP notes. I
truly appreciate your taking the time to assist me.

Best 73,

Tod, K0TO



On 11/8/14, 11:17 PM, "Tod" <tod at k0to.us> wrote:

>I have an FT1000MP.
>
>Recently I used the tuner to adjust the SWR to a low level for
>transmitting. The tuner functioned properly and the SWR level dropped to
>close to 1:1 .
>
>Later, I changed frequency sufficiently to know that I should retune.
>This time when I pressed the TUNE button I got the WAIT light but no
>change in SWR and no action I could detect occurring with the tuner.
>
>I switched the output to a 50 ohm dummy load. Turned off the tuner and
>sent CW at about 10 watts output. The SWR showed full scale. If I
>increased the RF output the limiting circuits in the radio cut it back to
>perhaps 35 watts of output.
>
>I checked the output with an independent power meter. The power out was
>at the level shown by the FT1000MP power meter. The reflected power shown
>by the independent meter was close to zero. The SWR shown on the
>independent meter was about 1:1.2 which was expected. The FT1000MP still
>showed full scale SWR.
>
>I would welcome any comments or suggestions from people reading this
>concerning how I might correct this problem.
>
>Tod, K0TO
>
>
>Sent from my iPad air
>
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