[ICOM] SWR problem on 706Mk2G

[John Geiger]

Hi Gary,

On 15m it was using a monoband 15m Moxon, and on 6m a 3 element monoband
yagi. I had a different 706MKIIG a few weeks ago and don't remember these
problems. Just picked up another 706MKIIG so will try it out when I get
home and see if I get the same results.

73 John AF5CC

On Fri, Dec 25, 2015 at 3:18 PM, Gary Fiber <gfiber at comcast.net> wrote:

> What kind of antenna is it? If not a dipole and have the room, build one
> up and see if that changes the outcome the the affected bands. Antennas
> with a lot of tuning traps can be problematic.
>
> Have or can you borrow an antenna analyzer to see if the antenna exhibits
> either inducting or capacitive reactance on the bands the 706 does not like
> ?
>
> You may have to make some antenna adjustments to neutralize the reactance
> as much as possible. Though as many will say that component will never
> generally reduce to nothing, but you may make the antenna useable with the
> 706.
>
> Have a ham friend near by to test the 706 on his antenna system?
>
> In my 11 years at Icom, there were times SWR issues were from a final amp
> being
> Spurious. Generally it was due to the amp oscillating for some reason.
> Possibly as another suggested a faulty low pass filter if within the radio.
> Also an oscillating final many times presents no output power control. Also
> ran into weird issues with some antennas so testing into a non reactive
> load was in order.
>
> Did you get a chance to try the 706 into a dummy load?
>
> Sorry I do not have a better answer.
>
> Gary P. Fiber K8IZ
>
>
>
> > On Dec 24, 2015, at 9:38 PM, John Geiger <af5cc2 at gmail.com> wrote:
> >
> > Hi Gary,
> >
> > If it is a reactive component that the 706MKIIG doesn't like, what is the
> > best way to handle that?
> >
> > 73 John AF5CC
> >
> >> On Sat, Dec 19, 2015 at 5:26 PM, Gary Fiber <gfiber at comcast.net> wrote:
> >>
> >> Does the SWR straighten out when you transmit into a dummy load? I
> always
> >> question use of an antenna as a standard test jig even if "Ok" with
> other
> >> rigs. Maybe the PA is spurious on 15 and 6 meters. Maybe some reactive
> >> component in the antenna the 706MK II does not like. Icom's were pretty
> >> tight for correct SWR specs, some other rigs like Kenwoods don't care
> and
> >> will be happy into almost a 3:1 mismatch, Icoms like 1:5:1 maybe 2:1 at
> the
> >> most.
> >>
> >> Gary P. Fiber K8IZ
> >>
> >>
> >>
> >>> On Dec 19, 2015, at 12:33 PM, John Geiger <af5cc2 at gmail.com> wrote:
> >>>
> >>> I recently purchased a used ICOM 706MK2G and it seems to have swr meter
> >>> issues on a couple of bands.  This occurs on 15 and 6 meters where the
> >> swr
> >>> is reading higher than what it should.  Has anyone seen this before, or
> >>> knows how to fix it?
> >>> I tried tightening the circuit board screws and that didn't fix it.
> >>>
> >>> 73
> >>> John AF5CC
> >>> ----
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> > ----
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> > Icom Users Net: Sundays, 1700Z, 14.316 MHz
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> > To support QSL/QTH.net: http://www.qsl.net/donate.html
> ----
> Your Moderator: Dick Flanagan K7VC: icom-owner at mailman.qth.net
> Icom Users Net: Sundays, 1700Z, 14.316 MHz
> Icom FAQ: http://www.qsl.net/icom/
> To support QSL/QTH.net: http://www.qsl.net/donate.html
>