Looking for opinions on the BEST manual ladder line tuner with 50-ohm coax
connection to rig (built-in balun).

Main criteria I'm looking for are low loss, and wide impedance matching
range (my Nye Viking M-II won't quite tune my inverted V on the high end
of 40 meters presumably because combination of ladder line length and
antenna length presents a too-high impedance at that frequency).

Power capability is secondary ... I run 200 watts with no desire to go any
higher ... but I think they're all mostly capable of legal limit these
days anyway.

Thanks...

In article ,
"Rick (W-A-one-R-K-T)" wrote:

Looking for opinions on the BEST manual ladder line tuner with 50-ohm coax
connection to rig (built-in balun).

Rick-

Look for one of the old Johnson Kilowatt Matchboxes. They have a true
balanced output. There is no "balun" with a ferrite core to soak up
energy.

Fred
K4DII

Fred McKenzie wrote:

Look for one of the old Johnson Kilowatt Matchboxes. They have a true
balanced output. There is no "balun" with a ferrite core to soak up
energy.

Fred
K4DII

Ferrite core baluns soak up energy? Tell me more.

Roy Lewallen, W7EL

On Tue, 31 Jul 2007 13:58:46 -0400, Fred McKenzie wrote:

Look for one of the old Johnson Kilowatt Matchboxes. They have a true
balanced output. There is no "balun" with a ferrite core to soak up
energy.

Good afternoon, Fred.

Yeah, I had one of those, sold it several years ago for $300, needed the
money at the time but probably should have hung on to it... :-(

On Tue, 31 Jul 2007 17:00:19 -0400, "Rick (W-A-one-R-K-T)"
wrote:

On Tue, 31 Jul 2007 13:58:46 -0400, Fred McKenzie wrote:

Look for one of the old Johnson Kilowatt Matchboxes. They have a true
balanced output. There is no "balun" with a ferrite core to soak up
energy.

Good afternoon, Fred.

Yeah, I had one of those, sold it several years ago for $300, needed the
money at the time but probably should have hung on to it... :-(

Palstar is probably the best in parts quality, but pricey. Ten Tec has
an L-circuit design. I sent my last MFJ tuner back, a 989d, real iffy
in quality.

Another way to go would be to do a search on eBay; the old Heathkit
2040 tuners still auction at reasonable prices.

bob
k5qwg

A good link coupled tuner is your best choice (a la' the Johnson
Matchbox). The reason is simple. It's a naturally balanced tuner. No
need to force the transmitter's unbalanced output into a balanced
antenna feed line via a balun (balanced to unbalanced) because there
is no direct connection between the transmitter & the feedline. The
coupling between the transmitter & the feedline occurs by way of two
closely spaced inductors (coils), one is the primary or link the other
is the secondary.

You can homebrew a link coupled tuner fairly easily although the
small, 250 watt Johnson Matchbox (available on ebay for about $100)
can handle 1000 watts PEP SSB since the Matchboxes are rated for
continuous duty AM fone.[Formula 1000 watts SSB -50% for no carrier =
500 watts - 50% for one sideband = 250 watts]. I have two.

The only drawback for the Johnson Matchbox is they don't extend down
to 160 meters (if you want to work 160).

If your interested in homebrewing your own link coupled tuner, google:
K1JJ Tuner
From the search results you'll be able to figure out how to build one.
I built one [not pretty] that works great. I added a cap to tune the
link.



Good Luck

Terry
W8EJO

If it hasn't been mentioned, the SAMS may probably be the ultimate
unit: http://www.eham.net/reviews/detail/6677 However, its cost is
probably equal to what many have invested in their entire shack. Still
not cheap, but more reasonable, is the AT-515:
http://www.hamware.de/hardware/tuner515/at515-e.htm Both were
represented at Dayton this year, and are clearly not Might Fine Junk.



--
Alan
WA4SCA

Both of these designs are of the Balanced L or Double L variety. Both
require a balun at the input to convert the 50 ohm unbalanced output
of the transmitter to the balanced tuner & feedline. You still haven't
gotten away from the main cause of inefficiency & power loss which is
the balun. [see http://www.somis.org/bbat.f1.jpg]

These double L tuners can be a PITA to build & use also. You need two
identical inductances at all times in the circuit. This requires
either some mechanical means of driving two identical roller inductors
simultaneously (so that the inductance in each leg always matches) or
two identical switched inductors with exactly the same tap points.

The link coupled design of the Matchbox takes the balun (and it's
potential for power loss) out of the circuit. They are also much
simpler designs, easier to homebrew & tune.

Terry
W8EJO





On Aug 1, 12:19 am, Alan WA4SCA wrote:
If it hasn't been mentioned, the SAMS may probably be the ultimate
unit: http://www.eham.net/reviews/detail/6677 However, its cost is
probably equal to what many have invested in their entire shack. Still
not cheap, but more reasonable, is the AT-515:http://www.hamware.de/hardware/tuner515/at515-e.htm Both were
represented at Dayton this year, and are clearly not Might Fine Junk.

--
Alan
WA4SCA

On Wed, 01 Aug 2007 11:44:12 -0000, Harry7 wrote:

Both of these designs are of the Balanced L or Double L variety. Both
require a balun at the input to convert the 50 ohm unbalanced output
of the transmitter to the balanced tuner & feedline. You still haven't
gotten away from the main cause of inefficiency & power loss which is
the balun. [see http://www.somis.org/bbat.f1.jpg]

These double L tuners can be a PITA to build & use also. You need two
identical inductances at all times in the circuit. This requires
either some mechanical means of driving two identical roller inductors
simultaneously (so that the inductance in each leg always matches) or
two identical switched inductors with exactly the same tap points.

The link coupled design of the Matchbox takes the balun (and it's
potential for power loss) out of the circuit. They are also much
simpler designs, easier to homebrew & tune.

Terry
W8EJO

I wonder if you have built a balanced L tuner? I made mine using only
hand tools and a drill press and had no problems. Also why do you say
they are a PITA to use? I adjust mine using only two knobs - the same
number of adustments I use on my Matchbox. Yes, I have both tuners.

Also, just how much of that terrible inefficiency and power loss does
that balun have? In the link you gave the balun consisted of nothing
more than a length of coax. There would be even less loss using a W2DU
type balun in that it requires a shorter length of coax.

Additionally, my balance tuner will give a 1:1 match on all the HF
bands (and anything in between) - something the Johnson Matchbox will
not do.

So are you talking from experience or just hear say?

Danny, K6MHE

Harry7 wrote:
Both of these designs are of the Balanced L or Double L variety. Both
require a balun at the input to convert the 50 ohm unbalanced output
of the transmitter to the balanced tuner & feedline. You still haven't
gotten away from the main cause of inefficiency & power loss which is
the balun. [see http://www.somis.org/bbat.f1.jpg]

The best way I have found to tune a balanced antenna
and feedline system, especially at high power, is at:

http://www.w5dxp.com/notuner.htm

The balun always sees a purely resistive differential
impedance between ~35 ohms and ~75 ohms. A 1:1 balun
with a choking action of 1000 ohms will virtually
eliminate conducted common-mode currents. Symmetrical
placement of the feedline to the antenna reduces
inducted common-mode currents. The needle on the MFJ
current meter barely moves on the most sensitive scale.
Under these circumstances, a w2du balun is not lossy.
--
73, Cecil http://www.w5dxp.com