Hi Jim,
I don't know. If the 590 tuner is off, the output of the 590 should be
the same as the 480. I think that the 480and the 590 use the same final
transistors.
Bob, K8LR, [log in to unmask]
On 11/27/2014 1:06 AM, Jim Gammon wrote:
> Bob, the thing is, that when I push the tune button on the
> external tuner, it doesn't chatter like it did when connected to
> the TS480 when it was trying to tune to the antenna. It's kind
> of caused me to wonder if it is working or not, but it seems to
> be working at least some times. Jim WA6EKS
>
> ----- Original Message -----
> From: Bob Tinney <[log in to unmask]
> To: [log in to unmask]
> Date sent: Wed, 26 Nov 2014 21:34:05 -0500
> Subject: Re: Question about using an external tuner with the
> TS590
>
> Jim,
>
> I prefer an external tuner as they are not as lossy as most
> internal
> tuners. My 590 tuner drops my power output by 10 to 15 watts and
> my
> Palstar 2K tuner shows no measurable loss in to a dummy load.
> One thing
> that can get a ham in trouble is if you have both your internal
> tuner
> and external tuner both turned on. The output on the rig could
> get such
> a high impedence that it could arc over or blow a fixed
> capacitor.
>
> Bob, K8LR, [log in to unmask]
>
> On 11/26/2014 9:23 PM, Jim Gammon wrote:
> I am using the internal tuner in my Ts 590 but still have my
> small external tuner in line that I used with the TS 480. I
> have
> noticed that I don't get much action from the external tuner
> like
> I used to get when it was connected to the 480. Seems like the
> internal tuner in the 590 is handling most or all of the tuning.
> My question is, can I take the external tuner out of the line?
> Thanks for your thoughts, Jim WA6EKS
>
> ----- Original Message -----
> From: Bob Tinney <[log in to unmask]
> To: [log in to unmask]
> Date sent: Wed, 26 Nov 2014 21:15:50 -0500
> Subject: Re: SWR, antenna tuners, and reflected power
>
> I have to add something here, I used to think that you had to
> have a
> perfect match to maximize efficiency. But I now realize that if
> you
> have a good, wide range, antenna tuner, you can match almost
> anything.
> You can even load up an 8 foot whip on 160 meters, but the
> radiation
> efficiency will be very low and your tuner will get very hot or
> arc. I
> have an Alex loop that is 3 feet in diameter and it gets out
> surprisingly well even on 40 meters, but you can only use up to
> 20 watts
> do to the close spacing in the tuning capacitor on the loop.
>
> Bob, K8LR, [log in to unmask]
>
> On 11/26/2014 4:24 PM, Tom Behler wrote:
> Ron:
>
> Thanks for the excellent concept review on SWR, reflected
> power,
> and antenna
> tuners.
>
> We all need reminders about this sort of thing from time to
> time.
>
> In fact, I'm now thinking of making some modifications to my
> station, and am
> trying to decide whether I can effectively do so with my
> current
> antenna
> arrangement. As you may recall, I use an Alpha Delta DXCC
> nulti-band dipole
> on 40 through 10 meters, and a Cobra ultralite senior antenna,
> mainly for
> the lower bands.
>
> While these antennas have kept me on the air on the HF bands
> over the past
> few years, I do wonder sometimes whether I might try something
> else to
> improve my situation. I do have limited space here, though,
> which makes the
> issue of alternate wire antennas a bit challenging. A tower
> and
> beam are
> also out of the question at this time for financial and other
> more practical
> reasons.
>
>
> Anyway, your remarks are quite timely here, so thanks for
> sharing them.
>
> Tom Behler: KB8TYJ
>
>
> -----Original Message-----
> From: For blind ham radio operators
> [mailto:[log in to unmask]]
> On Behalf Of Dr. Ronald E. Milliman]\\`
> Sent: Wednesday, November 26, 2014 4:07 PM
> To: [log in to unmask]
> Subject: SWR, antenna tuners, and reflected power
>
> I am sure most of you know all about SWR (i.e. Standing Wave
> Ratio), antenna
> tuners, and reflected power. However, it might be worth our
> discussing it
> anyway for the benefit of those who might not be as familiar
> with these
> relationships as others. Many of us use antenna tuners, both
> manual and
> automatic, for obtaining the best possible impedance match at
> the output
> point of our transceivers with the objective of getting the
> SWR
> as close to
> 1.0 to 1 as we can. A perfect match for most rigs is when the
> transceiver
> sees a 50 ohm load at its output. Anything above a 1:1 SWR
> represents some
> level of mismatch. Most of our transceivers can tolerate some
> mismatch
> before it begins to reduce the power output as a means of
> protecting the
> circuitry of the transceiver, and if the SWR or mismatch gets
> high enough,
> it will cause the transceiver to reduce its power output to
> zero. Many of us
> have transceivers, like the Kenwood TS-590 and similar rigs,
> that have
> built-in automatic antenna tuners. These tuners work
> extremely
> well for
> matching the impedance presented to the transceiver at its
> output, providing
> this mismatch isn't too high. How much is too high varies to
> some extent
> from one make and model of transceiver to another. If the
> mismatch is so
> large that the rigs internal automatic tuner cannot bring the
> SWR down
> within an acceptable level, you are faced with either
> adjusting
> your antenna
> to achieve a better match at the point where the feedline
> connects to the
> antenna, or you will need to obtain an external tuner to do
> the
> job.
> External tuners, whether manual or automatic, tend to have
> much
> wider ranges
> for matching the impedance of the feedline to the 50 ohms the
> transceiver
> wants to see at its output. A match at the transceiver's
> output
> does not
> mean there is a match at the point where the feedline actually
> connects to
> the antenna. Even if the impedance at the output of the
> transceiver is
> matched perfectly with an antenna tuner, there can be a very
> substantial
> mismatch at the other end of the feedline where it connects to
> the antenna.
> The larger this latter mismatch, the less actual power will be
> radiated by
> the antenna and the more power from the transceiver will be
> reflected back
> or remain in the feedline. What happens to the reflected
> power
> depends
> largely on the type of feedline used. The difference between
> the power
> radiated by the antenna and the output power of the
> transceiver
> is the
> reflected power and may be totally lost power, depending upon
> the loss
> rating of the feedline. If coax is used for the feedline,
> this
> reflected
> power ends up dissipating as heat in the coax and is pretty
> much
> totally
> lost power. If this heat is more than the coax can handle, it
> can burn up
> the coax. In contrast, open wire feedline is considerably
> less
> "lossy", and
> much of the reflected power ends up being radiated by the open
> wire feedline
> as opposed to ending up being dissipated in heat.
>
>
>
> I am building up to two very important points that, in my
> opinion, do not
> received nearly as much attention as they should. The first
> point is that
> reflected power is not good for your transceiver, or if you
> are
> using a
> linear amplifier, it is not good for your amp. If you are
> using
> a tube-type
> linear, it can handle or tolerate more reflected power than
> the
> solid-state
> type amps, but regardless, reflected power is bad for your rig
> and it is bad
> for your amp. Here is my second point: just because your
> antenna tuner is
> able to get the SWR down to 1.0 to 1 or an acceptable level at
> the output of
> your transceiver or amp, that does not mean the reflected
> power
> is zero or
> reduced to an acceptable level. Most rigs and amps today have
> built-in
> protection circuits that detect high SWR and high reflected
> power, and they
> will shut completely down if either the SWR or reflected power
> is too high.
> For example, I have a Kenwood TS-590 driving an Ameritron
> ALS-600, and my
> antenna is an 80 meter, full-wave loop. I feed the loop
> antenna
> with 50 ohm
> coax and use a 2.5 to 1 matching ballun at the feedpoint of
> the
> antenna. The
> loop works extremely well on all bands 80 through 10 meters,
> including the
> WARP bands. However, there is a sizable mismatch on some
> bands
> at the
> feedpoint of the antenna. Without an antenna tuner, this
> mismatch would
> present such a high SWR at the output of the transceiver or
> amplifier that
> the protection circuits would reduce the power to zero or, in
> the case of
> the amp, it would kick it off. The mismatch is so high that
> the
> internal
> tuner of the TS-590 cannot handle it. So, I use a LDG
> AT1000PRO
> II external,
> automatic antenna tuner, which has a much wider matching
> range,
> and it can
> handle the mismatch and the power of the ALS-600 just fine.
> However, even
> though I am able to get my SWR down to 1.0 to 1 on some bands
> and 1.5 to 1
> or better on the others, I cannot run the amp at full power
> because if I do,
> the reflected power is so high, over 50 watts, that it causes
> my
> ALS-600 to
> kick off. Therefore, I am forced to reduce my output power
> down
> to the point
> where the reflected power is low enough that it won't shut the
> amp down.
> Consequently, instead of putting out 600 watts from the amp, I
> have to
> reduce the power to where I am putting out only about 300
> watts.
> This keeps
> my reflected power level below 50 watts, which is the critical
> level for the
> ALS-600 amp, keeping it from completely shutting down.
>
>
>
> Many years ago, when I was a young, foolish teenager, I put up
> an antenna
> that had such a high SWR that I could get RF burns from the
> Microphone of my
> transmitter. The transmitter was a Heathkit DX-40, which had
> a
> PI-output
> circuit that would allow me to load-up about anything for an
> antenna, but
> back in those days, there were no protection circuits to
> automatically shut
> the rig down if the SWR or reflected power was excessive. As
> a
> result, the
> high SWR and reflected power from trying to load and extremely
> mismatched
> antenna caused my tank coil to get so hot that it melted the
> plastic
> insulators that separated the windings of the tank coil; this
> caused the
> tank coil to short, which, in turn, created a chain reaction,
> ending up in
> wiping out the entire power supply. My point is to simply
> illustrate what
> high SWR and reflected power could do to your transceiver or
> amp
> if it
> weren't for the protection circuits that are built into the
> modern gear.
> However, even with the protection circuits, it is important to
> strive to
> achieve the best possible resonant frequency match with your
> antenna and
> then, between the feedline and your antenna and again between
> the feedline
> and the output of your equipment.
>
>
>
> I've had three people write to me off list asking me questions
> that related
> to this whole topic, and so, I thought I would simply write
> this
> up and post
> it to the list. I'm not trying to show-off what I know;
> rather,
> I might be
> showing-off what I don't know because there is a lot more
> about
> this stuff
> that I know very little about, and I am absolutely certain
> that
> many of you
> know tons more about some of this stuff than I do. I'm just
> trying to be
> helpful to some of the people that might be new that do not
> understand some
> of these things.
>
>
>
>
>
>
>
>
>
>
>
> Dr. Ronald E. Milliman
>
> Retired Professor of Marketing
>
>
>
> President: Millitronics, Inc. (millitronics.biz)
>
> President: South Central Kentucky Council of the Blind
> (SCKCB.ORG)
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