antenna tuner,best bang for the buck?
Cm13141
antennas.What is the best bang for the buck tuner that I should check out?I
have a
Kenwood TS-930S that i run barefoot.
Thanks,
James
'Doc
That's sort of a loaded question (pun intended). It depends
on a number of things, how bad is the mis-match, do you ever plan
to use more than 100-200 watts, how much is too much($$). It never
really hurts to have 'too much' tuner. Especially with MFJ, always
select a tuner that handles at least twice your power output (3x is
better). If your open to used tuners, there are a bunch that would
work well for you. I have a Dentron MT-3000 that's never given me
any problems (not for sale). So, shop around, compare prices, go for
a tuner larger than what you need. Good luck...
'Doc
PS - You might consider building one, not really that hard to do.
KA9CAR
for less than $100.
John
KA9CAR
Cm13141 <cm1...@aol.com> wrote in message
news:20010328011036...@ng-fz1.aol.com...
Ralph Mowery
Johnson Matchbox was really designed for open wire feeders and does not
work very well with coax feed lines.
I am not big on the MFJ stuff, but if you have to buy a SWR meter then
one of the MFJ tuners that has a built in SWR meter such as the MFJ-948
is not too bad for the money. I recommend it over the similar MFJ
modles if you have a rig without tunig controls. YOu don't need the
built in dummy load some modles have and you really get an extra coax
output jack. The one I have does seem somewhat lossey on 80 meters on
the limitated testing I have done into a 50 ohm dummy load, but not
really too bad.
Dave Metz
>I have not checked it out but was told by an older ham the smaller
>Johnson Matchbox was really designed for open wire feeders and does not
>work very well with coax feed lines.
>
A few years ago the ARRL ran a two part artical comparing the various
antenna tuner circuits that are available. Its very interesting and
well worth looking up.
The old Johnson match boxes were excellent, but like you say, they are
primarly intended for matching to balanced open wire feedlines. The
popular "T" network tuners can match a wet noodle. The problem is
that they also suffer from high internal losses. They make great
advertising copy and that's about all.
The hands down winner is the old Collins 180S1 pi network tuner.
Collins as always "knows RF" and has the simplist and most efficiant
design. I built a duplicate of one using two 500pf transmitting
variable capacitors and a surplus roller inductor. I got the caps as
kits (yes kits!) for $40 each from Ten Tec. The inductor I found at a
hamfest for $20. The rest switches, fixed loading caps, etc. came out
of the junk box. BTW, you don't need a fancy box for a tuner. I've
built them on a wooden board and they worked just fine.
Bottom line, avoid the cheap stuff, if it sounds too good to be true,
it is! You can build a tuner for a fraction of what one costs
commercially. If you do want to buy one, check out the new "L"
network tuner of Ten Tec's. It will do most of what the old 180S1 did
and is available now. BTW, Ten Tec like Collins "knows RF," and their
equipment is very robust and repairable. I have their HF rig and it
is fantastic.
--73-- Dave WA0AUQ
Tom W8JI
wrote:
>The old Johnson match boxes were excellent, but like you say, they are
>primarly intended for matching to balanced open wire feedlines. The
>popular "T" network tuners can match a wet noodle. The problem is
>that they also suffer from high internal losses. They make great
>advertising copy and that's about all.
That isn't true Dave.
T network tuners are very efficient at most load impedances people
will run into. They are no worse than any other configuratation.
>The hands down winner is the old Collins 180S1 pi network tuner.
Pi-networks and L networks have the most restricted matching range of
any configuration. They are no more efficienct than a T using similar
components.
>Collins as always "knows RF" and has the simplist and most efficiant
>design. I built a duplicate of one using two 500pf transmitting
>variable capacitors and a surplus roller inductor. I got the caps as
>kits (yes kits!) for $40 each from Ten Tec. The inductor I found at a
>hamfest for $20. The rest switches, fixed loading caps, etc. came out
>of the junk box. BTW, you don't need a fancy box for a tuner. I've
>built them on a wooden board and they worked just fine.
Maybe for your load impedances, but not most people! I exclusively use
T networks here when feeding unknown loads.
Assuming resistive loads, the impedance limits of a pi-network tuner
with 500 pF capacitors is:
No load less than ~600 ohms on 160 meters.
No load less than ~180 ohms on 80 meters.
No load less than ~50 ohms except on 10 MHz and above.
I didn't bother with ten meters, because I don't know the minimum C of
the capacitors or the minimum L of the inductor. It is safe to assume
it would have a restricted matching range on ten meters for high
impedance loads.
Of course if the impedance presented at the tuner by the antenna
system is close to 50 ohms R and has the equivalent of series
capacitive reactance, you can null the capacitance with series
inductance and match low impedances, but that would be more luck than
planning.
The real reason T's are popular is they match the widest range of
impedances with the best results on the widest range of frequencies of
any network configuration.
73 Tom
Bill Aycock
some peoples hobby) , but- having owned several, and now owning two, I
have had nothing but good luck and results with the MFJ tuners. One
exception was a case where , as it turns out, someone had sprayed a
lacquer on the back, and I could get not contacts on the balanced wire
connectors, until I scraped them clean. (It sure kept the metal from
tarnishing, though)
MFJ has manuals available, and descriptive data on MANY tuners at
www.mfjenterprises.com. there are always a large number of tuners, of
all brands, on ebay- just search "antenna tuner"- (leave off the
quotation marks, and dont use the plural.) They average 40 to 50
listings.
Good luck- Bill-W4BSG
W6RCecilA
> Of course if the impedance presented at the tuner by the antenna
> system is close to 50 ohms R and has the equivalent of series
> capacitive reactance, you can null the capacitance with series
> inductance and match low impedances, but that would be more luck than
> planning.
Something I've always wondered - If the load is 50 ohms, a pi-net
tuner can be tuned for absolute minimum series inductance. Seems
under the same circumstances, a T-net inductor would be lossier.
--
http://www.mindspring.com/~w6rca
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Tom W8JI
wrote:
>Tom W8JI wrote:
>> Of course if the impedance presented at the tuner by the antenna
>> system is close to 50 ohms R and has the equivalent of series
>> capacitive reactance, you can null the capacitance with series
>> inductance and match low impedances, but that would be more luck than
>> planning.
>
>Something I've always wondered - If the load is 50 ohms, a pi-net
>tuner can be tuned for absolute minimum series inductance. Seems
>under the same circumstances, a T-net inductor would be lossier.
>--
>http://www.mindspring.com/~w6rca
That's true, in the case where a tuner is not needed, a direct short
from the input to output will have lowest loss.
But in that case it is not a network.
So what you are saying is the lowest loss network is a direct zero
resistance connection. That makes perfect sense to me...except it
isn't a tuner. It's a short.
73 Tom
W6RCecilA
> So what you are saying is the lowest loss network is a direct zero
> resistance connection. That makes perfect sense to me...except it
> isn't a tuner. It's a short.
But the point is that a pi-net tuner is capable of a near short
and a T-net tuner isn't (unless there's a bypass switch). With
all three components at minimum values, the pi-net is low loss.
With all three components at maximum values, is the T-net low
loss? I'm not saying it isn't - I'm just asking.
Tom W8JI
wrote:
>But the point is that a pi-net tuner is capable of a near short
>and a T-net tuner isn't (unless there's a bypass switch). With
>all three components at minimum values, the pi-net is low loss.
>With all three components at maximum values, is the T-net low
>loss? I'm not saying it isn't - I'm just asking.
In the real world the limits of the components always prevent perfect
devices.
The T is a mirror of the pi. If you could set all the components in a
T for maximum values, it would be the same as setting all the
components in a pi for minimum values.
The ideal network would probably be one that allows the same
components to be switched from a T to a Pi.....but that won't happen
because of complexty.
But all of this is beside my point.
My point is the pi network offers the LOWEST impedance/frequency range
of any network configuration with given components, and that is why
they have fallen out of favor for antenna tuners.
It isn't that people are stupid, or cheap, or bad engineers and
foolishly select a T network out of pure unvarnished stupidity.
The truth is simply that dollar for dollar you get the widest matching
range, best overall efficiency, and power handling from a T network.
73 Tom
W6RCecilA
> The truth is simply that dollar for dollar you get the widest matching
> range, best overall efficiency, and power handling from a T network.
Plus a high pass filter. :-)
Thomas Beltran
replaced my MFJ-941E, which is now just a tuner for a shortwave receiver.
These two tuners are on opposite ends of the spectrum. The MFJ had a low
power handling capacity and fixed inductor positions. The Heath handles a
full gallon (or so the book says) but has a fully variable inductor.
Inside, the components are very heavy duty looking. With the MFJ, I always
felt that the optimum position was "in between" the fixed positions. With
the Heath tuner, I am able to tune up everything I need. This is not a bash
on MFJ, the comparison would well be accurate for any similar tuner.
So, I would agree with others who have posted, get a tuner with the widest
range, and as much power handling ability as possible. I had lots of
arching problems with the smaller MFJ and I've had none with the Heath. I
also did not personally like the crossed-needle meter on it. The Heath has
dual meters which read SWR and power output - very convenient.
And if price is an issue (as it was for me) get a used tuner.
--
Thomas E. Beltran
Attorney at Law
2501 West Burbank Blvd.
Suite 200
Burbank, California 91505
"Cm13141" <cm1...@aol.com> wrote in message
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Dennis Collin
Hard to say ... they range from MFJ to Nye-Viking MBVA ... quite a
range.
1) not MFJ
2) Vectronic DLP300 is a nicely built, good performing tuner (built by
MFJ now, so I can't say what they're like now)
3) Take a look at LDG Electronics autotuner AT-11!
Look on eham.net for product reviews to see what users think about
their tuners.
Bob Miller
That's like asking which mini-van gives the best bang for the buck.
A lot of them do...
I've had good luck with an MFJ 989C. No complaints. Great metering system.
Rugged looking components. Whether it's good bang for the buck, who knows?
You really don't have a lot of choices. MFJ makes a bunch of tuners. Ten Tec
makes one. Vectronics makes a few. Ameritron makes a couple. Nye-Viking makes
one. There's an X-Match tuner that runs over a thousands dollars.
I'd just get an MFJ. When it arrives, take the case off, and make sure there are
no cold solder joints. Re-solder them, if necessary. Put it back together... I'd
recommend getting one of their kilowatt or plus models, regardless of the power
you're running. Your components can never be too rugged.
There's always eBay, but you never know whether those tuners have been hit by
lightening or whatever...
Good luck!
Bob
k5qwg
Ralph Mowery
it.
Donnie
Tom W8JI
> NYE VIKING=No Substitute...
Unless you want wide impedance matching range on 160, 80 or 10 meters.
73 Tom
W6RCecilA
> Should have mentioned the NEW one I got did have a loose screw or two in
> it.
Sounds like my ex-wife.