[Yaesu] FT1000MP won't transmit on just 40M

[Carl Lester via Yaesu]

Hi Cecil, thank you for your response.  Yes, after I wrote my original post, I realized I wasn't really specific enough.  What is happening is it appears everything is OK, just NO RF out on 40M. The TX lite comes on, everything appears normal. The ALC level goes up, but no RF Out.  I did not look at the DC supply current and voltage reading while trying to transmit, that is an excellent idea! Additionally, by the way, there is no RF out in any mode, CW, SSB, AM, RTTY (FSK) nothing. 
Now, a little update as of this morning:  Last night before going to bed, I unplug the 1000MP from the 120VAC wall outlet.  Then this morning I went in pushed the power button and it didn't come on because I had forgotten I unplugged it last night. :-)  So turned off the power button, then plugged the rig back in and then pushed the power button and it powered up. It was still on 40M CW where I had left it last night.  I then hit the my CW key, and what do you know, it transmitted!!! Full RF out. I was happy to see it working again, but that is certainly disturbing.  I tried changing bands around, turn it back off and on, change modes, turned it off and on some more, and no problem. Still working fine. Went off to take a shower, etc. and so about a half hour later, went down to the shack, turned it on, and it is still working fine! 
So I don't know what to think. Your idea about the PIN diodes make sense, but they wouldn't "get better" so not sure.  I wonder if I got a sticky relay somewhere specific to the 40M band?  
Also, by the way, I have had this problem occasionally over several years! Usually cycling the power fixes it, so I've been living in denial, and going on, HI HI, until last night when nothing seemed to help. 
Thanks for your help and suggestions, Cecil.  If (when) it happens again, I will be sure to see if it is trying to draw current! That would be a good clue for sure. 
My other radio is an even way older FT990.  It just keeps going! Never a problem. (knock-on-wood)
Best 73!Carl,  K2YR
 

     On Friday, February 27, 2015 10:07 AM, Cecil <chacuff at cableone.net> wrote:
   

 Chester when you say won't transmit at all can you be more descriptive?  Does the TX LED come on when the radio is keyed?  With the meter looking at the DC current being drawn does the current being drawn increase when the radio is keyed?  It's been a while since I've owned a MKV so I'm not clear on the metering positions but you should be able to monitor the DC voltage and current.

You could have a transmit bandpass filter relay in trouble...or if they are switched in and out with pin diodes one of them has failed...like I said it's been a few years since I owned one or looked at a schematic for one...

To me that's the most logical explanation.

If the current drawn by the radio on that band increases as on other bands when keyed on 40m but there is no RF output...that is most likely the cause.  I'm sure you have already verified that you have selected the correct antenna port for that band? I believe that's switchable from the front panel.

Good luck with it...

Cecil
K5DL

Sent using recycled electrons.

> On Feb 26, 2015, at 9:41 PM, Carl Lester via Yaesu <yaesu at contesting.com> wrote:
> 
> Hi All!  I have had this problem every once in a long while, where my 1000MP won't transmit on 40M.  It works every where else, but not 40M. In the past I usually turn it off, and back on, and it works again! Sometimes it takes 2 times.  Anyway, tonight I can't get it to comeback.  I've done a global reset, but no help. 
> Any ideas?  
> Thanks & 73,Carl,  K2YR
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