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Reviews For: Johnson KW Matchbox

Category: Antenna Tuners/Matching Networks

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Review Summary For : Johnson KW Matchbox
Reviews: 19MSRP: $150-$350 USed DOC
Description:
Link coupled balanced ant. tuner, pre-1970
Product is not in production
More Info: http://www.qsl.net/w2wdx/articles/a4.html
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00194.5
KB2FCV Rating: 2020-01-13
Great tuner for Balanced Line Time Owned: more than 12 months.
I've owned this tuner for almost a year and I've been very satisfied with it. I am feeding a 100 foot dipole with 600 ohm open wire line (trueladderline.com). It loads all the bands 80-10 and even 6! (although I have a beam for that..). These tuners are great low loss balanced line tuners and the KW matchbox is built like a tank and will handle the power. If I ever have an amp again, I know it will handle it just fine. I'll have this tuner for a long, long time.
KD5PNT Rating: 2014-07-07
excellent matcher Time Owned: more than 12 months.
I have both the 1 KW version and 275 watt version and use both on field day with my G5RV fed with 450 ohm twinlead . only problem I have had is I cannot get a match on 10 metres .

have had both for 15 years .
WA6JGM Rating: 2014-07-02
Works great for what it was designed for Time Owned: more than 12 months.
I have been using this tuner for 43 years, and have had no regrets. All tuners have their limitations and quirks and I can accept them. This thing is built like a tank, takes a lick'n and keeps on tick'n.

The only other tuner I have that will beat this one is a TMC TAC-1 due to its continuous coverage from 2.0 to 30 MHz but, it has its limitations but I can live with them.

I use a Versa Tuner for field work, it too has limitations but I can live them.

For all the nae sayer's out there, show me the all in one perfect tuner that has no limitations or quirks.

There are many good tuners out there but let's what shape they're in with 50 years of service on them......See you in 50

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Earlier 5-star review posted by WA6JGM on 2014-07-02

I have been using this tuner for 43 years, and have had no regrets. All tuners have their limitations and quirks and I can accept them. This thing is built like a tank, takes a lick'n and keeps on tick'n.

The only other tuner I have that will beat this one is a TMC TAC-1 due to its continuous coverage from 2.0 to 30 MHz but, it has its limitations but I can live with them.

I use a Versa Tuner for field work, it too has limitations but I can live them.

For all the nae sayer's out there, show me the all in one perfect tuner that has no limitations or quirks.

There are many good tuners out there but let's what shape they're in with 50 years of service on them......See you in 50
N6YW Rating: 2014-06-20
Excellent for what it was designed to do. Time Owned: more than 12 months.
My property has a small footprint and having been restricted to using vertical antennas for the past decade, I finally designed a system which would allow me to fit a Cobra Ultra-Lite Jr. I run mostly vintage AM equipment and at the QRO level. The Johnson KW MB has done an outstanding job of matching the load required for my operating routine, which is mainly 75 & 40 meter phone. The signal reports I have received have been excellent and not so much because of my choice of tuner but because it works with the antenna I chose. It's a system and while many ops may balk at the KW MB, many don't know how to use one properly or understand what is going on under the hood. The voltage rating of the design is well suited for amateur use, and the quality of the components are very high. My doublet fed with ladder line has brought me much happiness here in Venice Ca, and the many ops who I chat with every week are a testament to how well this works.
If you understand how this tuner works and what it's designed for, then it makes perfect sense to own and use one for the proper application.
I have owned and used the very best commercially made tuners built in the past 60 years and none of them performed any better. I love this box!
KJ4BIX Rating: 2013-01-02
Only option for balanced Time Owned: more than 12 months.
If you are running an MFJ or others, and attempting to run a balanced antenna with ladder or open wire, look at the current per leg on the ladder line. You will probably find a drastic difference in the current between the legs. Using the Johnson the currents are practically identical. Legal limit even on AM is no problem on the Johnson KW.
W2WDX Rating: 2012-12-04
Best Balanced Tuner Time Owned: more than 12 months.
I have owned Matchboxes for years and have yet to find a better balanced tuner. One note the Kilowatt tuner is not a 1KW PEP tuner. Back then things were rated for input and using AM. So the Kilowatt's rating is good for about 3-4KW PEP. The loss in this tuner is so low as to be almost pointless, even on a tough match. No other tuner today comes even close to the loss figures on these Johnson's. For tuning a true balanced random length doublet it is hard to find anything better. Unless you plan on building your own link-coupled tuner, nothing made today or in recent years will compare. Loss is a big deal and additive, so if your using a L or Z tuner with coax and a balun, you can kiss about 50% (or more) of your power goodbye by the time it gets to your feed point. With the Johnson your at about 90% transfer. So when QRO you actually get 1200w to your feedpoint instead of 750 lost. Think about that.
K9VUJ Rating: 2011-02-11
Best of the best Time Owned: more than 12 months.
The king of balanced line tuners. Using a 130 foot center fed wire with 100 ft of 600 ohm ladder line I am able to match every band from 80 to 10 meters.
K6JHD Rating: 2006-12-25
Matchbox missing the High Z single wire input. Time Owned: more than 12 months.
I have owned a KW Matchbox since the 1950's. I could never get it to load a single wire High Z antenna. My V-Beam was designed for 20-15 & 10 meters and the Matchbox worked on these bands as expected. I tried to load the V-Beam on 40 and 80 meters with no success with the ladder lead in shorted together on the single wire input. So I wondered why this was happening. I removed the tuner from the case and compared the tuner with the schematic and the instruction sheet. My tuner has two ceramic feed-throughs for a balanced line input and a coax connector for a coax antenna feed line. The back panel does not have a connector for a High Z single wire connection. To use the coax connector for a coax feed line, the left feed post, the one under the ground strap, has to be grounded! The two connectors for the balanced line input work normally. The schematic, and the instructions indicated there should be a High Z input connector matching the two for the balanced line. My Matchbox did not have one! I believe there was an engineering snafu that led to the omission of the high Z input connector on my model of the Matchbox! I installed a glass feed through next to the coax connector and connected it to the end of the loading coil near the back panel. This is the High Z point of the coil. Now the two wires of the ladder line of the V-Beam can be connected to the High Z output connector and the left most connector is grounded. Using this method with the Matchbox, my KWS-1 was loaded up on the V-Beam conected as a single wire antenna and I made my first contact on 80 meters with this xmtr and antenna! The SWR was 1.04:1 with 700 watts.
KC8HXO Rating: 2006-01-21
Just the facts Time Owned: 0 to 3 months.
Of course, you may have different results, but here are mine:

1)Able to match by EDZ on all bands 80-10M, INCLUDING WARC.
2)My Palstar BT-1500A was not able to do that.
3)No sweat running legal limit through it.
4)Quality, USA made, from back when we did it right.
5)Will stay in the shack with my Ten Tec 238A, until I am SK.

Good luck with yours!
DD3LY Rating: 2002-10-14
Poor for today Time Owned: 3 to 6 months.
As WA8KJP mentioned the Johnson tuner has really limited tunig range (there is a review about tuners in an old QST of the 90s). I built a balanced L-network out of two roller inductors and one vacuum variable, as WA8KJP did, but simplified it: a 50:12.5 Ohm transmission line broadband BalUn instead of the cap between BalUn and the coils. The effect: Just two points to tune and tuning range again starts at low-Z.