eHam.net - Amateur Radio (Ham Radio) Community

Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net


Reviews Categories | Antenna Tuners | JOHNSON MATCHBOX "LITE" 300 WATT Help


Reviews Summary for JOHNSON MATCHBOX "LITE" 300 WATT
JOHNSON MATCHBOX  Reviews: 28 Average rating: 4.6/5 MSRP: $(missing—add MSRP)
Description: 275 watt Plate Input Power rated, 80-10 Meter tuner
Product is not in production.
More info: http://members.aol.com/tcsopr/vkgmbx.htm
Email Subscription
You are not subscribed to this review.

Subscribe!
My Subscriptions
Subscriptions Help

You can write your own review of the JOHNSON MATCHBOX "LITE" 300 WATT.

<— Page 2 of 3 —>

W1BKZ Rating: 5/5 Jan 28, 2007 17:34 Send this review to a friend
Only the best there is.....  Time owned: more than 12 months
OK, so I'm prejudiced. E.F.Johnson stuff, in general, is very well designed and implemented. No cheap parts here. Sure, there are better tuners out there, but the prices are upwards of $600 or more. I payed $75 for my Matchbox (used), and spent the better part of an hour cleaning it up!! What a pleasure to match my Zepp on all bands except 160. No strain, no pain, just fine results!! And, it goes well with my Viking II.
 
KW4N Rating: 2/5 Oct 28, 2006 06:48 Send this review to a friend
Limited Range  Time owned: more than 12 months
This tuner will NOT tune balanced line on all bands on a multiband antenna because it lacks the range. Doublet feedpoint impedance varies from very low to very high; this tuner can't handle it. Many operators get around this by varying the length of their feed line for each band by cutting in the appropriate length with knife switches. Typically, the various lengths are mounted and switched inside the shack. Now, do you really want various lengths of open wire line stretched around your shack? Bet your wife doesn't!
The only truly balanced tuner that I'm aware of that can handle the wide impedance range is the Palstar 1500BL for about $700. A good tuner is a lifelong investement, so buy the best. If you can't afford it now, wait until you can.
73's Dave
 
N2OLP Rating: 5/5 Jun 18, 2006 18:34 Send this review to a friend
Excellent Tuner  Time owned: more than 12 months
I have always loved these tuners and have two of the small ones. They are great. I don't miss using a balun. My only complaint is that there are so many screws you have to remove to take the thing apart! Of course, the only time I have had to do this is when I looked to see if there was any damage done by a previous owner. And, not once did I see any damaged internal components. I can't understand why no one is building a link coupled tuner anymore.
 
AC0DV Rating: 5/5 Feb 27, 2006 20:39 Send this review to a friend
GREAT Tuner.  Time owned: 0 to 3 months
I just replaced an MFJ-949E with the Nye-Viking version of the matchbox. (Model 250-25)

I had a problem tuning the top of the 80M band with my 280' horizontal loop... I think the impedance is too low for those frequencies.

I tried changing the length of the ladder line for a day... I started at about 70' and kept cutting 1-2' lengths off until it got to about 43'... but still couldn't match the 80M band.

So I put in two 680pF (6kV) caps across the output variable capacitor.(If interested go READ the PDF file "New Life for the Johnson Matchbox".)

I did the "mod" in a completely reversible manner. Of course I'm attaching the caps at the rear of the unit... so it takes a few seconds to switch to 80M from any other band. (Hooking up and unhooking the caps.) Perhaps I need to get a relay and a switch... but I needed to make sure the caps worked first. (I wouldn't mind having everything inside the grounded case.)

I used 680pF 6kV caps since I could buy them locally for $4.00 each... 500pF 15kV caps were available for $20.00 each... but I figured I'd try the cheaper caps first. They work well... so I see no reason to spend the additional money.

Now it tunes everything with no problems. (Haven't tried 160M since the antenna won't work well on that band anyway... at least not without massive losses.)

This tuner feels a lot more "solid" on the tune than the MFJ did... and it's MUCH easier to find a repeatable setting than the MFJ was.

It's nice to be able to get rid of the balun.

As a BONUS this unit says it will handle 500 watts.. and I've read it will do 1000 PEP with no problem. (The 500 watt label on the back of the unit is generally for AM carrier.)

All in all... I would highly recommend a matchbox to anyone using balanced line. (But keep in mind you may need to add some caps for 80M and definately if you plan on using 160M.)

Keith -- AC0DV
 
W9ECJ Rating: 5/5 Jan 17, 2006 18:48 Send this review to a friend
Great Original  Time owned: more than 12 months
Bought it 60 years ago. Old Reliable. Mine came with the Directional Coupler, the cylinder that enables the SWR feature. The Directonal Coupler is a second and separate piece from the tuner. The tuner also has the built-in relay to work with old tube gear--switches between the receiver and the transmitter, so when you transmit, the receiver B+ is automatically disabled and the receiver antenna terminal is automatically grounded.
To use with solid state transceiver. I energize the relay with 117 volts so that the tranceiver path for transmitting and receiving is the same. The caviat in the manual cautions is to keep the coax between the coupler and the transmitter short, about 3 inches. I find that it works fine even with a 3 foot coax at that spot. My antenna is a short dipole for 40 meters with loading coils, so antenna is 38 ft. long. My antenna is twin 450 leadin from the antenna all the way to the tuner. No balun, so SWR is about 3:1. I can switch between antenna tuners and rigs. Though I get a perfect 1.0 SWR with my MFJ, there appears to be no difference in reported signal strength between the MFJ and the Johnson Matchbox. The old tube stuff is not sensitive to an imperfect SWR. You can see the setup at my web site http://www.adelphi.edu/~allendon/
 
KC8HXO Rating: 5/5 Oct 15, 2005 15:33 Send this review to a friend
Superb  Time owned: more than 12 months
Excellent matching capabilities, and WELL constructed. Put this along side MOST tuners made today, and it will make you laugh at what the new fellows call a "300 Watt" tuner! Of course this was made back when the power was rated at INPUT watts, so it was probably rated for around 200W OUT. But of course that was AM carrier, and that would put the PEP power OUTPUT rating at around 800 Watts. Mine has been handling legal limit with no qualms at all, matching my W7FG Doublet (BUY ONE!!!) on all bands 10-80M. Works like a champ.
 
N4OGW Rating: 5/5 Sep 4, 2003 10:44 Send this review to a friend
favorite tuner  Time owned: more than 12 months
I've used one of these for a while (~15 years), and really like it for matching open-wire antennas. At several QTH's I've used this tuner with a ~100' dipole on all bands 80-10m. The tuner I have has the relay circuit ripped out, no need to keep it with a transceiver.

It is really not a "low-power" tuner either...I've used mine with
1.5KW on some bands!
 
N8UOO Rating: 5/5 Oct 14, 2002 08:48 Send this review to a friend
Best Available  Time owned: more than 12 months
I run a Zepp to handbook length with open wire feeders on 80 through 10 and the matchbox has never failed me. I tried a "modern" matching device and it corrected the SWR but its iron core ran hot on some bands. I deduced that the heat was robbed from my output power and my reports were not up to par so back to the matchbox. I have not tried the box on bands for which it was not designed but would change my antenna and feedline dimentions if I wanted it to work well on alternate bands. Is the Nye Viking the same design? Does anyone know?
 
W2XS Rating: 5/5 Aug 1, 2002 11:17 Send this review to a friend
Eliminated TVI  Time owned: more than 12 months
I used to use a Drake MN75 with the 4:1 balun on the output. I played with the feedline length to get it to match a 132-foot ladder-line fed CF antenna on all bands. But I had some TVI on some bands when the kids were watching TV in the next room. This TVI disappeared with the Johnson Matchbox in line, perhaps due to the better balance. I also think that the matching range of the Johnson is a little better than the Drake, but there are probably wider-range antenna tuners out there besides these two. As they say - your mileage may vary.

I also bypassed the T/R relay since today's transceivers take care of that function nicely.

73,

John W2XS
 
N1BEC Rating: 5/5 Jul 31, 2002 18:12 Send this review to a friend
Have 3 matchboxes, they work good but have their limitations.  Time owned: more than 12 months
Hi Folks! I've been using Johnson Matchboxes for something like 15 years. I'm pretty happy with them. I currently own two of the little matchboxes and one Kilowatt Matchbox. I use the KW mb with the Johnson 500 and the BC-610. It worked killer on a G5RV fed with open wire line. I had no matching problems of any sorts. I did modify it (in a manner so it can easily be returned to stock condition) so that the tuner is out on RX. I had to use a bushing to keep a high impedance line off ground, and it was hilarious when the RF from the JV500 ignited the rubber grommet due to extreme HV. I currently feed a 600 foot loop with the same ladder line. Again, no matching problems of any sort.
The two little mb's are in the little station in the house: One is stock, and goes to the 32V3, and the other has been "modified" before I got it (read: butchered) to do away with the T/R circuitry, so it's permanently in line. This one goes to the Kenwood 520-S. I'm working towards switching them i line with the old SA-13/U knife switches. Both untis work fairly well. One MAJOR complaint is the stock units seem to develop high resistance contacts across the receive contacts on the relay. It's a HUGE pain in the butt, pulling all the screws out, and cleaning the contacts. Most of the units I've found have this problem.
I've only had one instance where the mb has not performed well. My backup antenna is a 40 M dipole, fed by open wire. It tuned OK on 40, not at all on 20, fair on 15, great on 10, and only the high end of 75. Of course, using a 40 M dipole on 20 M, changes the feedpoint impedance from low impedance to a range in the thousands of Ohms, way beyond the tuning range of even the mb. The solution was to use a 4:1 balun, it still worked great on 40, and now worked well on 20, 15, & 10. 80 M op presented a minor problem, a short antenna presenting a lower impedance. I simply turned the 4:1 balun around, and now dropped the impedance by a factor of 4, and the 40 M antenna worked GREAT on 80M!
I have seen mods for using the mb on 160M, but have not tried them (nor do I want to mess up a good unit!).
I give the units a hearty two thumbs up!
 
<— Page 2 of 3 —>


If you have any questions, problems, or suggestions about Reviews, please email your Reviews Manager.