[Mobile-Portable] re: Radio Shutdown problem

Mon, 19 Aug 2002 14:45:18 -0500

Scott-

You're not alone. I have the same problem on my setup with an Icom 706IIG
and a High Sierra Antenna. If I transmit on 20 it shuts down. Every other
band works fine! I too have found the problem goes away if I place the
remote head back onto the body of the radio. Ferrite beads on the separation
cable have not solved the problem. I also have toroids on the DC line at the
base of my High Sierra. My solution has been not to transmit on 20m and use
17 instead! The upside of this has been some really nice QSO's that I
probably would never have found on 20m. Sorry if this doesn't help solve
your problem, but sometimes it's just good to know someone else out there
had the same one.

-Dallas (KB9QPE)

> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]]On Behalf Of Scott Neader
> KA9FOX
> Sent: Sunday, August 18, 2002 3:59 PM
> To: [email protected]
> Subject: [Mobile-Portable] re: Radio Shutdown problem
>
>
> One update... I found that if I remove the separation cable on
> the 706, and
> put the head directly on the radio, the problem goes away.  So,
> if I don't
> use a separation cable (impossible for driving of course) the
> problem goes
> away... and also if I disconnect the 12v at the base of the antenna, the
> problem goes away.
>
> Another observation:  When everything is connected normally (using
> separation cable and 12v connected to antenna)... when I am on 20 meters
> and have the antenna tuned so it is NOT resonate on 20, the radio signals
> are very quiet as you'd expect... but I am also hearing "digital
> noises".  When I turn the dial, I hear more of them... it would seem that
> I'm "hearing" the communication between the head and the radio.  And, get
> this... if I disconnect the 12v leads at the base of the
> antenna... I can't
> hear the digital sounds anymore.  Also, if I completely remove
> the antenna
> from the car, the digital noises go away.
>
> I am stumped and frustrated.  Any ideas would be appreciated.
>
> I'm going to dig and see if I can find some sort of clip-on
> ferrites to put
> on the separation cable to see if that helps, and maybe I can find enough
> to put some more on the 12v motor cable.  I am not hopeful this
> is going to
> help.
>
> - Scott
>
> >Hello all.  I'm in a bit of a panic, and hoping you can assist.
> I'm going
> >on a trip and wanted to have this working before I left, but it is not
> >looking good.  Actually, it was working fine, but something has
> changed...
> >I'm not sure what.
> >
> >My set up is:  IC-706MKIIG with Hi-Q Antennas 3/80 screwdriver-type
> >antenna and AmCom ASAC Automatic Screwdriver Antenna Controller.
> >
> >My problem:  Every time I try to apply power on 20 meters (even
> the Lowest
> >power setting on the 706) the radio immediately shuts down.
> >
> >Solution?  If I unhook the 12 volt line to the Antenna motor,
> the problem
> >goes away.
> >
> >The Antenna Mfg suggests putting Toroid Cores around the 12v leads, as
> >close to the base of the antenna as possible.  The manual says:
> >
> >"If you ordered the red toroid cores to use as RF chokes on the motor DC
> >lines,
> >install them as close to the motor as possible. Simply loop the
> motor leads
> >through the cores, one at a time."
> >
> >I do have the red toroid cores, but I guess I didn't install them
> >correctly... I separated the + and - leads, and put one toroid
> around each
> >lead, looping each lead through a toroid two times.  So, I have a toroid
> >on the + lead, with two loops around the toroid, and I have a toroid on
> >the - lead, with two loops around the toroid.   I guess it's
> worth ripping
> >it apart and trying to keep the leads together and loop them
> BOTH through
> >both toroids.
> >
> >However, later in the manual it states:
> >
> >"It is also a good idea to use the clip-on, data type line chokes on the
> >wires coming out of the antenna motor leads. Wrap the wires around the
> >core at least once. Do the same
> >thing for the coax cable. Toroids may also be used. This will eliminate
> >the RF �pick-up� that may alter VSWR readings or affect the vehicle�s
> >electronics. To prevent RF feed back on the motor lines you can
> add a pair
> >of 100 �H, 2 amp chokes at the base of the antenna."
> >
> >FYI, the installation manual for the antenna is located at:
> >     http://www.hiqantennas.com/Stealth-Mounting-Tips.pdf
> >
> >Is a "100uh 2 amp choke" something I'm going to find at Radio
> Shack, or am
> >I hosed for this trip?  Any other suggestions to stop this
> problem?  If I
> >can't get 20m to work, I might as well just throw my tri-magnet mount on
> >the truck and bring my pile of HamSticks.  They work, but then to change
> >bands, I have to pull over, which doesn't work when it's late at night
> >and/or when the kids are napping. :-(
> >
> >I've got 24 hours.....
> >
> >73 - Scott KA9FOX
>
>
>
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