Tom, yes, my problem went away when I wired my TM-V71a directly to my car
battery, rather than plugging it into the assessory socket. My impression is
that the TM-V71a is a bit more voltage/current sensitive than my other rigs.


Ron



-----Original Message-----
From: For blind ham radio operators [mailto:[log in to unmask]]
On Behalf Of Tom Behler
Sent: Sunday, November 01, 2015 5:51 PM
To: [log in to unmask]
Subject: Re: Interesting TMV71A Issue

Ron:

I'm replying to the entire list here, so that anyone else who is interested
will be kept in the loop.

It's very interesting that you have had the same type of issue.  Did the
issue get resolved when switching power supplies?

As I said in my last post, I'm starting to wonder if my 17-year-old Astron
RS35 power supply might be starting to fail, and may want to drag out
another supply that I have around here just to either eliminate or confirm
that possibility.

I guess what puzzles me is that I had absolutely no problem of this sort
with my TS590 when doing my marathon for the Pennsylvania QSO Party several
weeks ago.

Of course, that all may not mean anything if the supply is now starting to
fail, but it just seems weird that the problem would occur so suddenly, and
with the TMV71A, rather than my TS590, my MFJ 998 auto-tuner, and my ALS600
when on HF, all using my Astron RS35 supply.

Tom Behler: KB8TYJ


-----Original Message-----
From: For blind ham radio operators [mailto:[log in to unmask]]
On Behalf Of Dr. Ronald E. Milliman
Sent: Sunday, November 01, 2015 6:37 PM
To: [log in to unmask]
Subject: Re: Interesting TMV71A Issue

Tom, I have encountered a problem that sounds very much like yours with my
TMV71A too. I discovered that my problem was caused from an inadequate power
source to operate my TM-V71a on high power, and in some cases, even in the
medium power position. 

Ron, K8HSY



-----Original Message-----
From: For blind ham radio operators [mailto:[log in to unmask]]
On Behalf Of Tom Behler
Sent: Sunday, November 01, 2015 5:18 PM
To: [log in to unmask]
Subject: Interesting TMV71A I

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