Have you checked all power connections, ie at the power supply, at the rign and also the inline fuse?

-----Original Message-----
From: For blind ham radio operators [mailto:[log in to unmask]] On Behalf Of Tom Behler
Sent: Sunday, November 1, 2015 6:18 PM
To: [log in to unmask]
Subject: Interesting TMV71A Issue

Hi, everyone.

 

Well, last night, I got rid of the gremlin that was causing issues with my ability to play selected audio files using Winamp, but now, another gremlin has appeared in my shack.

 

This time, I'm experiencing a very strange problem with my Kenwood TMV71A.

 

The problem occurs mainly when trying to transmit with high power on 440, but it happens occasionally when trying to do so on 2 meters as well.
Basically, when I transmit with high power, especially on 440, the rig shuts off for a split second, but then comes back on.  It's almost as if the rig is not happy transmitting on high power for some reason, again, especially on 440.

 

I discovered this issue late this afternoon, as I was doing my usual monthly tests of equipment, antennas, etc., at least as best as I can from here in the shack at the home QTH.

 

In trying to diagnose the problem, I have done the following things so far:

 

1.  My first thought was that something has gone wrong with my outdoor Diamond X200 VHF/UHF antenna, which is fed with RG9913 coax and is on the roof of my house at a height of approximately 35 feet.  I took SWR, as well as forward and reflected power readings using my TW2.  Both on 2 meters and 440, adjusting the meter for each gand as I went.  my SWR's on each gand are between 1.2 to 1 and 1.3 to 1.  On medium power, my forward power on each band is between 9 and 10 watts, and my reflected power is either at 0 watts on 2 meters, or point 2 watts on 440.

 

2.  I then tried switching jumpers between my TW2, and the Diamond X200 connection on my MFJ window feed through panel.  Again, no change.
Admittedly, I haven't swapped all jumpers out, but at least the initial jumper swap didn't change the results.

 

3.  I then did a V F O re-set on the TMV71A, with again, no change in my results.  I'm a bit reluctant to do the full re-set, but may do so as a last resort, since I have the TMV71A programming cable, and also have all memories and menu settings saved in a data file for the rig.

 

One other thing I might try is to see if this happens with the TMV71A that I typically use when camping out at the RV.  It is here in my shack in a box for the winter.

 

Before I go too crazy with all this, though, I'd like to know whether anyone else has experienced this issue, and if there are other ideas out there that I might want to try.

 

Thanks as always for the help.

 

Tom Behler: KB8TYJ