Stating individual cases where something worked proves nothing.
I've had half a dozen cases where it did not work and other matchboxes did.
In order to gain clarity on this, you must try it with all kinds of
antennas; resonant antennas, long antennas, short antennas, odd sized loops,
etc.
What the Johnson does well is push equal amounts of current into both wires
of the feedline with relatively high efficience, if and only if it finds a
match.
What it does poor is match over a very broad matching range.
You don't have to trust me; try it as I have and compare it to an MFJ-974 or
MHF-976.
OR... simply read the ARRL test report where the ARRL shows several balanced
matchboxes and their matching ranges, including the JVM.
Now I guess I have to go research the issue it was printed in because it's
probably too much work for some of the readers.
> "A New Generation of Balanced Antenna Tuners", by Joel Hallas, W1ZR, QST
September 2004.
OR, simply do what I have said her MANY TIMES, go to my web site, find the
page on MATCHBOX-SHOOTOUT
And read the page, plus download the file at the bottom of the page.
THERE you will find a nice colorful Excel spreadsheet comparing the matching
range of the various matchboxes.
THERE you will see that the JVM was indeed limited in matching range.
THEN go read my web page on how to fix it.
AND THEN YOU WILL HAVE THE BEST MATCHBOX EVER! ;-)
73
Rick, DJ0IP
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Carter
Sent: Saturday, July 16, 2016 9:32 PM
To: tentec@contesting.com
Subject: Re: [TenTec] OT: Question to the group
On 7/16/2016 10:13 AM, Carter wrote:
> On 7/15/2016 6:59 PM, Jim Allen wrote:
>
>> I had one of those [135 foot dipole fed with ladder line], not at >
>> 60', about half that. CC&Rs and all that.
>
> The exact setup I've got, also at 30 feet.
>
>> What is a "well designed truly balanced antenna tuner?" From what >
>> I've read, there aren't many.
>
> Johnson Matchbox, kW or 275 watt version, not "perfection" but
> certainly very good -- and readily available at a fairly modest price.
>
> Just my 2 cents...
>
> Carter K8VT
>
Sorry, forgot to mention it earlier...
Not to say my Johnson kW matchbox is the "best ever"; however, it works
flawlessly with my FT1000MP and 135 foot ladder line fed dipole on ALL
(including WARC) bands. Worst case is 2.1:1 on 30 meters, all other bands
1:1.
Carter K8VT
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