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

   Home   Help Search  
Pages: [1] 2 Next   Go Down
  Print  
Author Topic: External vs built-in tuner  (Read 5130 times)
KD8HMB
Member

Posts: 138




Ignore
« on: February 02, 2008, 03:19:39 AM »

I'm trying to learn about the various HF transceiver units available within my budget constraints and see that there are some that offer a built-in tuner, such as the FT 450 and FT 450AT.
What is the real advantage of having the tuner built instead of having it external. Is is convenience, ease of use, or is there a better performance match when it is built in?
The price for a FT 450 without the tuner is $ 625 and with tuner $720. If I have to buy a tuner anyway, should I get one external that can be used for any brand of HF unit, or is it really better to get the one with the tuner built in?
A related question - if built-in, does the tuner work equally well with dipole and vertical antenna?

Thanks
Logged
TANAKASAN
Member

Posts: 933




Ignore
« Reply #1 on: February 02, 2008, 04:08:25 AM »

I suggest you purchase the cheaper rig without the antenna tuner then spend the money on a good external antenna matching unit. Why?

1) The internal tuners are built using the cheapest and smallest componentsthat will fit inside the box. This means small toroid cores and capacitors with voltage ratings that they only just get away with. An external antenna tuner can use much better components

2) An internal tuner controlled by the rigs CPU will drop out and indicate a match at somewhere between 1.3:1 and 1.2:1 and you will never know about the wasted power. If you use an external tuner you can adjust for a 1:1 match.

3) You will probably find that the rig has a poor SWR meter as well, use an external one.

4) If something dies inside your rig then you will lose the transceiver AND the tuner whilst it is in the shop, this cuts down your options for a loan rig.

5) Connect a rig which has an internal tuner to a linear amplifier and you may see some weird effects including PA oscillation. A lot of linears like to see a purely resistive source on their inputs.

Tanakasan
Logged
AA4PB
Member

Posts: 12665




Ignore
« Reply #2 on: February 02, 2008, 09:44:25 AM »

The difference between 1.3:1 and 1:1, especially on the HF bands, is insignificant.

Internal tuners are more convient but also more limited than most external tuners. Internal tuners are usually limited to handling a maximum SWR of 3:1 whereas external tuners can be had that cover a much wider range of impedances. Internal tuners are generally fully automatic while external tuners can be had in either manual or automtic versions. An automatic tuner that covers a wide range of impedances is generally pretty expensive (over $300).

The best choice will depend largely on what you expect to use as an antenna. If you are planning an all-band doublet fed with ladder line then you'll need an external tuner. If you plan on using resonant antennas (with an impedance near 50 ohms) like a dipole, fan dipole, trapped vertical, or yagi then you may be happier with an internal tuner.
Logged
AA4PB
Member

Posts: 12665




Ignore
« Reply #3 on: February 02, 2008, 09:48:41 AM »

If you connect a rig with an internal tuner to an amp or to an external tuner then the internal tuner should be turned off. If you are planning on using an amp then you'll need an external tuner rated to handle the power of the amp as the tuner must be placed between the amp and the antenna.

As you can see, there is not a single answer to fit everyone. It all depends on your overall station design.
Logged
NA0AA
Member

Posts: 1043




Ignore
« Reply #4 on: February 02, 2008, 01:01:30 PM »

I would get an external tuner because the turning range is normally much wider - even the inexpensive auto tuners will easily accommodate greater than 10:1 whereas most built-in top out at 3:1 - fine if you are using resonant antennas, maybe a G5RV.

Plus, you can always use a new rig with an old tuner and vice-versa.
Logged
AB3CX
Member

Posts: 621




Ignore
« Reply #5 on: February 02, 2008, 02:34:05 PM »

If you ever get an amplifier, you won't use the internal tuner any more. You would need one that could handle more power. Internal tuners are convenient for touching up minor mismatches on basically resonant antennas, but don't do alot more than that. External tuners give more flexibility. Also, good external tuners also can have a balun, making them into Transmatches, capable of utilizing ladder line or long wire antennas. Look for a Dentron unit used, they made loads of great old tuners that go reasonably priced.
Logged
K7UNZ
Member

Posts: 691




Ignore
« Reply #6 on: February 02, 2008, 03:37:56 PM »

One more advantage to a decent external tuner is that the single tuner can be used with multiple rigs simply by putting a coax switch ahead of the tuner.

In my set-up I have four rigs (one with an amplifier), and a coax line over to my workbench, all of which feed into a single tuner via a coax switch.  A second switch on the tuner output can be used to select from an assortment of antennas/dummy loads, although a lot of tuners have that option built-in.

73, Jim/k7unz



Logged
VE7DQ
Member

Posts: 173




Ignore
« Reply #7 on: February 02, 2008, 08:57:48 PM »

If for no other reason, get the internal tuner for resale value.  The radio will have much higher appeal if and when you decide to sell it.  You might also find the internal tuner to your liking and it can always be turned off if not required.  Conversely, you can't use it if it's not there.  It's worth the hundred bucks.
Logged
KL7AJ
Member

Posts: 329


WWW

Ignore
« Reply #8 on: February 02, 2008, 10:16:30 PM »

If you mainly use antennas that are fairly close to matched, an internal tuner is fine for doing the "fine tuning."  Internal tuners are horrendous for matching short whips or voltage fed antennas, however, because these both are LARGE impedance mismatches that require High-Q, efficient components, which are too large to fit in most rigs.
Logged
ONAIR
Member

Posts: 1735




Ignore
« Reply #9 on: February 03, 2008, 02:54:43 PM »

   If you have an interest in experimenting with homebrew antennas such as long wires, an external tuner is the way to go.
Logged
WB2WIK
Member

Posts: 20542




Ignore
« Reply #10 on: February 04, 2008, 07:51:36 AM »

I'd definitely recommend buying it with the internal tuner.

In some cases, you might *still* need an external tuner, and of course if you ever add an amplifier you'll very likely need a high-power capable external tuner; however, one of the great advantages of these little mobile-sized rigs like the FT-450 is its "take it anywhere" capability.  For mobile work, camping, Field Day and many other things the internal tuner is very, very helpful and avoids carrying additional stuff.

WB2WIK/6
Logged
K7UNZ
Member

Posts: 691




Ignore
« Reply #11 on: February 04, 2008, 07:58:44 AM »

Actually, right now (at HRO)you can get the FT-450/AT for about $150 LESS than the rig without the ATU.

Current Yaesu $250 rebate makes it cheaper to buy it WITH the tuner than without......go figure!

73, Jim/k7unz
Logged
W5LZ
Member

Posts: 477




Ignore
« Reply #12 on: May 24, 2010, 05:15:40 PM »

If it isn't going to 'bite' your wallet too hard, then I would say get the internal tuner -AND- a good (meaning 'large') external tuner.  You've got the 'best' of both options.  An external tuner is a sort of 'one time' expense, one fairly 'large' one will handle most antennas.  Don't need it?  Don't use it.  I've found that those internal tuners do come in handy for mobile/portable times.
As already said, it just depends on what you can, or plan to do.
Paul
Logged
W6CD
Member

Posts: 213


WWW

Ignore
« Reply #13 on: May 31, 2010, 11:15:51 AM »

If you are using tuned antennas a limited range of an internal tuner is good enough to trim or improve the match.  If you are using un-tuned antennas, then the wider matching range of a external unit is a must.  So this is your first decision point.  If price/performance ratio is paramount consideration, then buying a radio without internal tuner and using an external auto-tuner is a good way to go.
Logged
NR4C
Member

Posts: 306




Ignore
« Reply #14 on: June 08, 2010, 11:51:38 AM »

No theory, no advice, but here's my story....

I have an old Icom radio without a built-in tuner.  I have a non-resonant loop antenna and bought a tuner to use it with my radio.  It worked well.  A few years down the line, I was offered a great deal on a Kenwood TS-570AD with the built-in tuner.  I hooked it up, and tried it, and it tuned my antenna well.  I haven't used the old tuner since.  A lot depends on your radio, tuner, and antenna.  Some work, some don't.

Good luck!

nr4c   -bill
Logged
Pages: [1] 2 Next   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!