All's well that ends well I'm happy to report. K2AV, Guy suggested I check the
SO-239 on the Rig Experts AA-170 and I found an open solder joint between the
back of the connector and the circuit board. Even with my close in glasses and
a magnifying glass it was hard to be certain. So a little solder and
'hop-a-long' rides again! It's working. Will check out the coax stub again to
see what the RE reads now.
Thanks Guy!
Terry
KI7M
> On June 9, 2018 at 10:42 PM terry burge <ki7m@comcast.net> wrote:
>
>
> Hi guys and gals,
>
>
> Well, to make a long story short my Rig Experts AA-170 has quite working.
> Looks normal but a 56 ohm resistor at the end of the 75 ohm coax reads
> infinite. On the MFJ-259b it reads 56 ohms. Check SWR and the MFJ reads
> 7.499.2 Mhz 1.1:1 SWR R=56/57 ohms X=0. Coax is 55' 4 3/8" long when I got
> very near 7500 KHz. With the shorted coax the MFJ-259b read 7.484.2 to 7.523
> Mhz, 20.2 SWR, R=2 ohms, X=0. Seems like the velocity factor is considerably
> higher than what was stated to me by DX Eng.. The velocity factor is some
> where around 0.84401... as best I can figure it. So I guess that makes it
> 0.84 VF FWIW.
>
>
> Anyway, I have it figured that 55' 4 3/8" will do the trick for my 80 meter
> 4-Square at 3.750 Mhz.
>
> But why my RE analyzer went out today I don't have any idea. Back to the MFJ!
>
>
> Terry
>
> KI7M
>
>
> > On June 9, 2018 at 6:59 PM terry burge wrote:
> >
> >
> > Good point Wes. I will see if I can find a decent value of resistor. My
> > Rig Experts AA-170 was purchased because I did not trust the readings my
> > MFJ-259b was giving me while working on my hytower. Pretty penny for these
> > antenna analyzers. But I will bet if it won't do the stub frequency checks
> > it won't do the velocity factor and more. Did work pretty good for checking
> > SWR and feedpoint impedance on antennas like the hytower. Really liked it
> > until this.
> >
> >
> > Terry
> >
> > KI7M
> >
> > > > On June 9, 2018 at 5:11 PM Wes Stewart wrote:
> > >
> > >
> > > Since he said the coax was 75-ohm, a 75-ohm termination would be
> > > better.
> > >
> > >
> > > On 6/9/2018 5:07 PM, Richard (Rick) Karlquist wrote:
> > > > > As a sanity check, terminate the coax with a 50 ohm resistor
> > > and verify
> > >
> > > > > > that you have good coax. Flat line at 1:1 SWR, etc.
> > > >
> > > > Rick N6RK
> > > >
> > > > On 6/9/2018 4:57 PM, terry burge wrote:
> > > > > > > I don't know what is wrong here but I keep getting in
> > > > this situation where my
> > > >
> > > > > > > > typing starts running back over my writing. I
> > > > will try again to reply.
> > > > >
> > > > >
> > > > > Joel,
> > > > >
> > > > > I have tried all that the manual says without
> > > > > success. All I see is the
> > > > > horizontal solid and dashed lines of R and X. No
> > > > > indication of a resonance
> > > > > point anywhere from 1880 KHz up to 10,500 KHz. Go
> > > > > figure? At least my
> > > > > mfj-259b is working old as it may be. Rig Experts is
> > > > > going to get a nasty
> > > > > note I think. Disappointing, huh?
> > > > >
> > > > >
> > > > > Terry
> > > > >
> > > > > KI7M
> > > > > > > > > On June 9, 2018 at 2:54 PM Joel Harrison
> > > > > wrote:
> > > > >
> > > > > > > > > > Hi Terry,
> > > > > >
> > > > > > I replaced the 1/4 lines on my 80 meter 4
> > > > > > square this past fall and used
> > > > > > my AA-170 to set the length with no problem.
> > > > > >
> > > > > > Just select "all" for the mode and set the freq
> > > > > > you're aiming for and then
> > > > > > trim the line until X equals zero with the far
> > > > > > end open. Should work fine.
> > > > > > I always calculate the length x VF then add a
> > > > > > few feet to start.
> > > > > >
> > > > > > 73 Joel W5ZN > > Hi guys and gals,
> > > > > > >
> > > > > > >
> > > > > > > > > > > I have got DX Engineering 75 ohm foam
> > > > > > coax to make the
> > > > > >
> > > > > > > > > > > > stubs/feeders for
> > > > > > > my Comtek 80 meter 4-Square and am
> > > > > > > finding some difficulty.
> > > > > > > Neither my
> > > > > > > MFJ-259B nor my Rig Experts AA-170 seem
> > > > > > > to indicate a 1/2 WL at
> > > > > > > 7500 KHz
> > > > > > > or a 1/4 WL at 3750 KHz? Or any frequency
> > > > > > > up or down from there.
> > > > > > > Seems to
> > > > > > > me the last time I did this a few years
> > > > > > > ago I didn't have a problem
> > > > > > > getting a 1/2 WL dip indicating a
> > > > > > > resonance location. But now I
> > > > > > > just don't
> > > > > > > get any indication of a resonance.
> > > > > > >
> > > > > > >
> > > > > > > DX Engineering said they had got some 75
> > > > > > > ohm foam coax that
> > > > > > > instead of
> > > > > > > 0.84 VF was more like 0.80 down to 0.76
> > > > > > > VF. But checking all the
> > > > > > > way down
> > > > > > > to 6000 KHz on 40 meters or 2500 KHz on
> > > > > > > 80 meters fails.
> > > > > > >
> > > > > > >
> > > > > > > My test is to use either antenna analyzer
> > > > > > > with a PL-259 installed
> > > > > > > at one
> > > > > > > end and an open or a short at the other.
> > > > > > > I started with 57'7" of
> > > > > > > coax.
> > > > > > > Tried both with the coax in a roll and
> > > > > > > strung out. What am I doing
> > > > > > > wrong?
> > > > > > >
> > > > > > >
> > > > > > > Terry
> > > > > > >
> > > > > > > KI7M
> > > > > > >
> > > > > > > 😞
> > > > > > > _________________
> > > > > > > Topband Reflector Archives -
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