[TenTec] Scout problems

Bob, WB2VUF wb2vuf@qsl.net
Fri, 26 Oct 2001 09:55:05 -0400


Definitely try the chokes on the power lead. The frequency display
jumping around is a symptom of voltage drop in the power cable, RF
getting into the power supply and causing the regulator to drop the
voltage, or RF getting into the processor board inside the Scout.
Try a different power supply. Some Astron supplies have been reported to
behave strangely in an RF environment. Also, try backing off the power
in the Scout a little. My Scout did the same strange things when driven
too hard. Don't go over 50 watts with it: try backing off to 40 or 45
watts. Some Scout users have put in a ground braid from the processor
board shield cover to a nearby circuit board ground. I did this but I
don't really know if it helps.

The "voice sidetone" may be "normal" My Scout does this too. It may be
due to incomplete muting or just the fact that the Scout has a lot of
circuits and  a lot of wiring crammed into a small space, so that there
is a lot of opportunity for internal stray coupling. I bet the new DSP
QRP rig will not have these problems, but it won't have the power of a
Scout.

			73,

			Bob WB2VUF



robert k stephens wrote:
> 
> Thanks everyone
> 
> In order to save bandwidth I'll try to respond to everyone with one message.
> 
> I don' think it would be the voltage regulator . I assume the factory would
> have spotted that when it was on their bench.(thanks)
> 
> I have Radio Shack ferrite assemblies on my microphone(s) cords and on the
> coax into the rig. I have also looped the coax into an air core coil choke.
> This didn't help. I didn't think to put a ferite choke on the power cord.
> I'll give that a try.
> 
> I have 3 factory power cords that I use interchangably. I'll try to pay
> attention to which one I'm using to see if the cords make a difference.
> 
> I don't have problems with all the bands all the time. This suggests a
> ground problem-sometimes in a given setup the ground might be good for one
> band and not another.  However, could it not also be caused by an
> intermittent problem in the plug in modules ?  Sometimes I can fix the
> problem by reinserting the module - sometimes that works and sometimes it
> doesn't.
> 
> I operate under many different conditions. Sometimes I'm inside/sometimes
> outside, sometimes 2 batteries in parallel sometimes car battery with
> engine running sometimes a power supply. For ground I have used cold water
> pipes, copper rods, metal fences and counterpoises. I have tried 3
> different mics. I have experienced fewer problems when the dipole is up
> high, free and clear with a well regulated power supply and short wide
> ground strap to good ground but I want to emphasize that I have also had
> problems under what I consider to be near perfect conditions.
> 
> The "guest" operator position at my club is what I consider to be near
> perfect. The tri band beam is up 45 feet, fed by quality coax. The ground
> strap is 1 inch wide in the shack and  it connects to buried 8 ft rods. The
> power supply is an Astron (30 amp ?) The configuration I used bypassed the
> tuner and went directly to the beam. SWR was under 1.5 to 1
> 
> Under this condition the frequency varied widely and wildly during
> transmit. I know from past experience that this means that my audio was
> extremely distorted and difficult to impossible to understand. The Kenwoods
> hooked up to the same situation worked fine and I did a little casual
> contesting breaking pileups and being heard the first time with ease. It's
> hard for me to not believe that something on the Scout is broken (either
> broken in the rig itself or a fault in the plug in modules). Why would the
> Scout be unusable in the same base station situation that the club's
> Kenwood performs well in ? In case I haven't said this before I used to
> have better results with the rig when I first got it than now. I'd like to
> save my money and keep the Scout.
> 
> Can anyone think of a variable in the triband/tower/8 ft rods/ Astron power
> supply set up that would cause a Scout's transmit frequency to jump around
> widely and wildly ?
> 
> tnx
> Bob KB1CIW
> 
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