Re: [TenTec] Jupiter Autotuner upgrade?

[John <jh.graves@verizon.net>]

The tuner is a MFJ- 949e rated at 300 watts.  I have not been able to 
find the specs other than it is  built to handle 300 W and will resonate 
most antennas.  It has tuned antennas for me for a long time without a 
protest.  Where do you find the specifications for the tuners?  I keep 
looking but only find the most general of specs, 300 watts etc.
My antenna is a G5RV with a 3/4 in twin lead feeder to normal coax.  I 
forgot who made it as I have had it up for a long time.  It is full 
size, not one of the ?double or half size antennas I see offered from 
time to time.  In the FWIW department the peak is about 40-45 ft with 
the ends about 25-30 ft on one end and probably 40 ft on the other.  It 
goes out over a slope on that side.  It works well for DX (that means  I 
can make contacts) but is very fussy close in (within 10 mi.) and seems 
very directive.   I have trouble working a few people who are close in, 
although they may have minor things like rock between us.  I am on Cape 
Ann err Manchester, MA (Gloucesterites get a bit fussy about who claims 
to reside on Cape Ann)  and there is a reason that one community is 
named Rockport.  I have never seen a pattern for the G5RV on bands other 
than 20 M and guess it is acting pretty much as an untuned dipole on 
bands other than 20 M.  Is this a bad assumption?
Thanks for the information.

73,
John / WA1JG


On 11/30/2011 3:33 AM, Rick - DJ0IP / NJ0IP wrote:
> John,
>
> The G5RV (if it is really built like the G5RV suggested antenna) has an
> impedance "close" to 50 Ohms on 80 and 40 and most other HF bands.  The
> Jupiter's built-in tuner will have no problem matching it.
>
> If you have a "G5RV-like" antenna, such as it has the length of the G5RV,
> but runs openwire all the way to the shack, then the answer is "maybe".
>
> You asked to compare it to your MFJ tuner but that is like saying you have a
> car and asking if the gas mileage of a new Corvette will be as good as the
> one you have - hi.  We can't answer until we know what car you have.
>
> If you dig into the specs of the MFJ tuners you will find that most specify
> that they can match up to about 1600 Ohms.
> Two or three say they can match up to 3200 Ohms.
> Some can match to 1200 Ohms, while there are one or two others that only
> match to about 800 Ohms.  BTW, it's the high power tuners which have the
> lower matching ranges.
>
> I will make a HUGE assumption here and say that the Jupiter's tuner will
> probably match about the same as the MFJ that can match up to 1200 Ohms.  It
> certainly is not going to match the range that the 3200 Ohms tuners can
> match.  Maybe someone who owns one can check the manual and see if the specs
> on the matching range are printed.
>
> 73
> Rick, DJ0IP
>
>
> On 11/29/2011 12:26 PM, John wrote:
> > I am considering adding the autotuner to my Jupiter.  My normal antenna
> > for now is a G5RV with plans for getting my R-7 Vertical back on the air
> > ASAP.  Other than making me feel better, what is gained by adding the
> > autotuner to the mix.  The G5RV gets quirky to tune on 80 and 40 using
> > my MFJ tuner. Will a G5RV be within the tuning range of the TT autotuner
> > with these bands and antenna?  Any experiences are appreciated.
> >
> > 73,
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