[TenTec] Jupiter frequency jump?

[K6atz@aol.com]

Don, 

As the others said, the Joop has a very different "VFO" so it's not doing 
that "digit twitching" thing that the Scout does.  But what you may be 
referring to is the fact that if RF gets inside the Jupiter, the frequency 
may zoom off across the band.  

The Jupiter has some fine DSP stuff in it.  Incoming signals sound great and 
transmit audio sound great.  But if there is RF around (and when isn't there 
if you're transmitting, especially with a vertical?) then RF may get in via 
the computer cable, via the remote knob cable, via the microphone, however it 
can.  RF can cause other problems; my Pegasus was even more sensitive in 
other ways.  With the Jupiter I only had the "frequency zoom" problem.  I was 
actually able to affect it by putting my hand on the remote;  a bead on the 
cable and other work was required.  

If you mention this to Ten-Tec tech support, you'll get nothing but a stern 
lecture about RF in the shack.  But I did a lot of work moving antennas, 
improving grounding and isolating ground loops without resolving the problem. 
  And none of my other radios - from a 1984 FT-102 to a 1997 IC-706 - have 
the same problem.  Both of my Ten-Tec radios did.  

The other radios have capacitors in strategic locations just inside all 
jacks, and beads built into their cables.  I source 75-cent serial cables for 
PDAs from China, and they all come with beads built in.  This is a serious 
shortcoming in Ten-Tec radios, which otherwise are renowned for their 
quality, and I can't understand why they would rather leave this to us to 
fix.  It makes their products really unsuitable for field day or emergency 
use.  

Although many Ten-Tec owners have this problem, about half of the folks out 
there seem fervently religious in their belief that this could never happen.  
Now, most of the guys supporting my contention e-mail me privately so they 
don't get flamed.  But I've personally never received anything but dignified 
engineering discussions in reply on this list.  So, comments anyone?  

Joe, K6ATZ