KPA500 and KAT500 Ports

[Gary Gregory]

I am so confused now I will just stick with the manual tuner with 3 antenna
ports.

Gary

On 14 July 2011 13:46, Tony Estep <[hidden email]> wrote:

> Suppose you really wanted to decide the best design strategy for a maker of
> antenna tuners. You might think as follows:
>
> All potential buyers have at least one antenna. Some have two, some three,
> etc. As you add more outputs on the back of the tuner, you increase
> potential sales, but you also increase costs. Note importantly that adding,
> for example, a third output increases the cost of units sold to hams who
> have only one or two antennas. Therefore, adding outputs may add some
> customers among hams with many antennas, but will also lose some sales to
> hams who don't want to pay for unused outputs. Moreover, adding outputs
> lowers profit margin.
>
> The number of units sold is some function of this increment to unit cost.
> And of course, total revenues is unit cost * number of units.
>
> The problem is to optimize profit: quantity * (price - unit cost).
> Recalling
> that quantity depends in part on unit cost, we can write this out and
> differentiate with respect to the cost of the added outputs. The point at
> which that derivative = 0 is the optimum amount to spend on extra outputs.
>
> In order to do this exercise with real numbers, one would have to have some
> idea of the elasticity of demand with respect to price, a number that may
> not necessarily be easy to pin down. Nonetheless, the point is to provide a
> better framework for decision-making.
>
> Tony KT0NY
> ______________________________________________________________
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--

VK4FD - Motorhome Mobile
Elecraft Equipment
K3 #679, KPA-500 #018
Living the dream!!!
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[Joe Subich, W4TV-4]

 > In either format I think that it should have not more than 2 inputs,
 > 3 unbalanced and one balanced output and that the tuner should be
 > capable of matching a 10:1 VSWR load. (As compared to 50 ohms)

There is a lot of lily gilding here ... the tuner, in either format
does not need more than two outputs following in the format established
in the K3.  One output can be either unbalanced (coax), balanced or
single wire.

It certainly does not require two inputs as it can't service more than
one RF generator (rig) at a time and would either follow a KPA-500 with
a single output or replace the KAT-3.

A 10:1 VSWR load rating is craziness - particularly for a 600W rated
tuner.  10:1 VSWR means 5KV/50A peak ratings ... something that would
handle 3:1 SWR at the W/VE "legal limit."  3:1 or 5:1 is far more
reasonable for a "high power" tuner ... and can handle the open wire
fed doublet or inverted L as long as the user avoids pathological
lengths of feedline (1/4 wave of open wire line) or antenna length
(full wave doublet or half wave inverted L).

> The desktop unit should be as small as possible but I personally
> don't think that 'P3 size' will be big enough due to the high
> voltages that can (and do) develop in the tuner, in a P3 sized case
> there would exist the real possibility of flashover with disastrous
> results for the tuner and / or amplifier / rig.

P3 size is entirely appropriate if the matching range is kept within
reason.  Elecraft have already discussed the P3 form factor.  Again,
multiple antenna outputs is complicated by a wide matching range -
the P3 format is entirely reasonable if antenna switching and matching
range are kept within reason.

> I also envisage that the remote unit will have to rely on RF sensing
> alone, due to the possible distances involved between it and the
> transceiver / amplifier unless some type of data bus capability is
> installed that is capable of operating over the long distances (10 to
> 100 metres or more) that is also compatible with the K2/K3/KRC2 etc.

There are several "high audio" communications protocols that would be
very suitable for multiplex operation over coax with the RF and DC
power.  Chip sets are readily available at reasonable prices and the
band splitting (high pass/low pass) filters are not unreasonable at
the 600 W level.  Even if multiplex operation is not desired, outdoor
rated CAT5/CAT6 cable is quite satisfactory for control to several
hundred meters with the appropriate drivers.

73,

    ... Joe, W4TV


On 7/13/2011 10:31 PM, Jeff Cochrane - VK4BOF wrote:

> Personally, I think that we need a reality check here people.
> Let's face it, what we 'want' and what we 'need' are two sometimes vastly different things.
> Wanting to be able to switch up to 18 antennas is so far outside the realms of sanity to try to implement in an antenna tuner it's ridiculous.
>
> Let's get back to basics, I am told that the KAT500 tuner will most likely be available in two formats, one a desktop unit and one a remote unit.
> In either format I think that it should have not more than 2 inputs, 3 unbalanced and one balanced output and that the tuner should be capable of matching a 10:1 VSWR load. (As compared to 50 ohms)
> Those are the basic requirements IMHO.
>
> Now, on to packaging.
> The desktop unit should be as small as possible but I personally don't think that 'P3 size' will be big enough due to the high voltages that can (and do) develop in the tuner, in a P3 sized case there would exist the real possibility of flashover with disastrous results for the tuner and / or amplifier / rig.
> I envisage something of similar size (for the desktop units at least) to a K3 if anything.
> This will give more than enough space for the tuner plus the associated switching needs to select the different antennae.
> The remote unit will no doubt be smaller due to not needing a capability of local human interaction and will probably have only one input.
> As well the remote unit will need waterproofing to IP65 or better.
>
> Functionality:
> I envisage that the desktop unit shall be not only able to select between the 2 rig inputs&  3 antenna outlets but can do so according to the band that the radio (I am assuming that an Elecraft K3 or least a K2 will be used with it.) is on and do so automagically via AUXBUS control.
> If the transceiver used is not an Elecraft rig (Shame on you!) then possibly the tuner should have some sort of RF sensing capabilities, ala KPA500.
>
> I also envisage that the remote unit will have to rely on RF sensing alone, due to the possible distances involved between it and the transceiver / amplifier unless some type of data bus capability is installed that is capable of operating over the long distances (10 to 100 metres or more) that is also compatible with the K2/K3/KRC2 etc.
> Failing that maybe a serial interface could be used but that would mean that level convertors and logic decoders would have to be used at either end, thereby complicating things even more. (And not to mention, adding extra cost to the units)
>
> Whatever the good folk at Elecraft come up with I don't mind betting that it's gunna be awesome, just like the rest of their gear! :)
>
> 73 de
>
> Jeff Cochrane - VK4BOF
> Elecraft K3 # 4257 + K144XV + KPA500 + PR6  = Fanbloodytasic performance!
>    ----- Original Message -----
>    From: Eric Swartz - WA6HHQ, Elecraft
>    To: Brendan Minish
>    Cc: [hidden email]
>    Sent: Thursday, July 14, 2011 10:01 AM
>    Subject: Re: [Elecraft] KPA500 and KAT500 Ports
>
>
>    Why not just use two KRC2s? They are complete and shipping. :-)
>
>    73, Eric
>
>    ---
>    www.elecraft.com
>
>
>    On 7/13/2011 4:22 PM, Brendan Minish wrote:
>    >  I think that 2 Antenna ports on the KAT500 is a good fit, after all 2
>    >  ports is what the K3 (+ATU) has so many of us have configured our
>    >  stations to work with this configuration
>    >
>    >  I would suggest however that there be an (optional?) module (s) for the
>    >  KAT500 that provides for sink or source outputs, one per band (plus a
>    >  few more?) that can be further configured via software to to clever
>    >  things (like selecting 2 different antennas for 80/75m, or multiple
>    >  bands on one antenna )
>    >  It would be even nicer if this was duplicated for the second antenna
>    >  output either in the same module or as a second user installable module.
>    >
>    >  These would be driven by the auxbus data that will presumably be fed to
>    >  the KANT500 and decoded by it's CPU anyway.
>    >  An input (per antenna port) that can be used to indicate to the KAT500
>    >  that the requested antenna is not available might also be a good idea so
>    >  that the KRC500 can then select the second choice on the other port
>    >  (complete with recalling the last used tunings for the secondary ) would
>    >  also be nice.
>    >
>    >  Think of this as the functionality of (2x ?) KRC2's built in and it
>    >  would make for superb versatility since the KRC500 could then be
>    >  configured to automate pretty much any external automatic antenna
>    >  switching arrangement.
>    >
>    >  I don't know if this is practical to fit into the box but it sure would
>    >  be nice.
>    >  The KRC2 may already form the basis for much of the required
>    >  circuitry/firmware.
>    >  The Sink/source outputs could be selected sink/source by internal jumper
>    >  and the output could be on DB15 or DIN connectors to minimise rear panel
>    >  real estate. (perhaps with pre-made breakout cable supplied )
>    >  Another option might be to have the 'Glue' internal to the KPA500 and
>    >  the Sink/source drivers in a 'dongle' to conserve internal space and
>    >  provide for easier breakout.
>    >
>    >  73
>    >  Brendan EI6IZ
>    >
>    >
>    >
>    >
>    >  On Tue, 2011-07-12 at 15:34 -0700, Eric Swartz - WA6HHQ, Elecraft wrote:
>    >>  Hi Gary,
>    >>
>    >>  Having 4-5 RG8 antenna cables, plus the input cable, hanging out the
>    >>  back of the desktop ATU is both likely to pull the ATU off the desk, and
>    >>  will easily not fit in the box size we are planning. It also adds a lot
>    >>  of complexity and cost to the basic ATU in order to accommodate more
>    >>  connections with the needed isolation etc. We certainly do not want to
>    >>  price the ATU out of the range of most hams, or make it too large.
>    >>
>    >>  Many of us use manual or automatic switches external to the amp / tuner
>    >>  to provide these functions.
>    >>
>    >>  A much better solution for those needing more than two auto-selected
>    >>  antennas is to use an external relay switch box, controlled by the
>    >>  radio. This has the advantage of getting the cables, clutter, and
>    >>  switching network off the desktop and either under the table or outside.
>    >>  There are certainly a number of external antenna switches out there that
>    >>  can do this, but if we offered something that was tightly integrated
>    >>  with the K3 (and KPA500/KAT500) as a product, what features would be
>    >>  desirable? (Number of antennas, rigs inputs, switching options etc.)
>    >>
>    >>  73, Eric WA6HHQ
>    >>
>    >>  ---
>    >>  www.elecraft.com
>    >>
>    >>
>    >>  ______________________________________________________________
>    >>  Elecraft mailing list
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>    >>  Help: http://mailman.qth.net/mmfaq.htm
>    >>  Post: mailto:[hidden email]
>    >>
>    >>  This list hosted by: http://www.qsl.net
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>    ______________________________________________________________
>    Elecraft mailing list
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[Brendan Minish]

1/ Tuner can select only for the output port in use, this leaves 'the
other choice' available for other radios. If the tuner is currently on
antenna port 2 then it does not drive the outputs associated with
antenna port1

2/ Tuner can remember previous tunings per selected antenna driver
(rather than per port)

5/ with an input for interlocking logic the KRC500 (& thus the
KPA500/K3) could be made aware when no antenna is selected and select a
a second choice or even inhibit TX

4/ Space savings, the KRC2 has buttons and features that are not
required 'just for selecting antennas'  

6/ more reasons to buy the KAT500 ;-)


The KRC2 still does not support 6m with the K3 and much of the 'glue' to
make this happen is going to be already in the KAT500 as it is already
going to have to decode the band and band segment that the K3 is tuned
to  

73
Brendan EI6IZ
 



On Wed, 2011-07-13 at 17:01 -0700, Eric Swartz - WA6HHQ, Elecraft wrote:

> Why not just use two KRC2s? They are complete and shipping. :-)
>
> 73, Eric
>
> ---
> www.elecraft.com
>
>
> On 7/13/2011 4:22 PM, Brendan Minish wrote:
> > I think that 2 Antenna ports on the KAT500 is a good fit, after all 2
> > ports is what the K3 (+ATU) has so many of us have configured our
> > stations to work with this configuration
> >
> > I would suggest however that there be an (optional?) module (s) for the
> > KAT500 that provides for sink or source outputs, one per band (plus a
> > few more?) that can be further configured via software to to clever
> > things (like selecting 2 different antennas for 80/75m, or multiple
> > bands on one antenna )
> > It would be even nicer if this was duplicated for the second antenna
> > output either in the same module or as a second user installable module.
> >
> > These would be driven by the auxbus data that will presumably be fed to
> > the KANT500 and decoded by it's CPU anyway.
> > An input (per antenna port) that can be used to indicate to the KAT500
> > that the requested antenna is not available might also be a good idea so
> > that the KRC500 can then select the second choice on the other port
> > (complete with recalling the last used tunings for the secondary ) would
> > also be nice.
> >
> > Think of this as the functionality of (2x ?) KRC2's built in and it
> > would make for superb versatility since the KRC500 could then be
> > configured to automate pretty much any external automatic antenna
> > switching arrangement.
> >
> > I don't know if this is practical to fit into the box but it sure would
> > be nice.
> > The KRC2 may already form the basis for much of the required
> > circuitry/firmware.
> > The Sink/source outputs could be selected sink/source by internal jumper
> > and the output could be on DB15 or DIN connectors to minimise rear panel
> > real estate. (perhaps with pre-made breakout cable supplied )
> > Another option might be to have the 'Glue' internal to the KPA500 and
> > the Sink/source drivers in a 'dongle' to conserve internal space and
> > provide for easier breakout.
> >
> > 73
> > Brendan EI6IZ
> >
> >
> >
> >
> > On Tue, 2011-07-12 at 15:34 -0700, Eric Swartz - WA6HHQ, Elecraft wrote:
> >> Hi Gary,
> >>
> >> Having 4-5 RG8 antenna cables, plus the input cable, hanging out the
> >> back of the desktop ATU is both likely to pull the ATU off the desk, and
> >> will easily not fit in the box size we are planning. It also adds a lot
> >> of complexity and cost to the basic ATU in order to accommodate more
> >> connections with the needed isolation etc. We certainly do not want to
> >> price the ATU out of the range of most hams, or make it too large.
> >>
> >> Many of us use manual or automatic switches external to the amp / tuner
> >> to provide these functions.
> >>
> >> A much better solution for those needing more than two auto-selected
> >> antennas is to use an external relay switch box, controlled by the
> >> radio. This has the advantage of getting the cables, clutter, and
> >> switching network off the desktop and either under the table or outside.
> >> There are certainly a number of external antenna switches out there that
> >> can do this, but if we offered something that was tightly integrated
> >> with the K3 (and KPA500/KAT500) as a product, what features would be
> >> desirable? (Number of antennas, rigs inputs, switching options etc.)
> >>
> >> 73, Eric WA6HHQ
> >>
> >> ---
> >> www.elecraft.com
> >>
> >>
> >> ______________________________________________________________
> >> Elecraft mailing list
> >> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> >> Help: http://mailman.qth.net/mmfaq.htm
> >> Post: mailto:[hidden email]
> >>
> >> This list hosted by: http://www.qsl.net
> >> Please help support this email list: http://www.qsl.net/donate.html

--
73
Brendan EI6IZ

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[alsopb]

Unfortunately, this scenerio is exactly what I expect many with
KAT-500's to actually try and tune.  Unless there is some logic built in
to the tuner to inhibit operation for these crazy conditions, the future
is going to be full of "toasted toroids."

The scenerio goes as follows.  The tuner tunes up a 8:1 SWR OK at tune
power levels.  The amp is turned on and "FLASH".  The amp might be
protected but the tuner won't be.

This isn't fiction.  The roadsides are littered with autotuners that
have been fried.  Of course the tuner is at fault, not the user....

A tuner is not a cure all.  You've got to get your antenna(s) to
reasonable impedance levels first.  Hopefully, Elecraft will supply some
kind of "operating range" info.  Prudent users will then stay within
those limits.

BTW how do you remote antenna tuner users protect against lightning
destroying the tuner?

73 de Brian/K3KO



On 7/14/2011 04:50, Joe Subich, W4TV wrote:
>
>
> A 10:1 VSWR load rating is craziness - particularly for a 600W rated
> tuner.  10:1 VSWR means 5KV/50A peak ratings ... something that would
> handle 3:1 SWR at the W/VE "legal limit."  3:1 or 5:1 is far more
> reasonable for a "high power" tuner ... and can handle the open wire
> fed doublet or inverted L as long as the user avoids pathological
> lengths of feedline (1/4 wave of open wire line) or antenna length
> (full wave doublet or half wave inverted L).


-----
No virus found in this message.
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[N2TK]

I do not have need of a tuner for any antennas so I am looking at this from
a K3/K3/KPA500 configuration

 The Magic Box to control:
- Minimum of 4 antennas per bank. Additional banks can be added so if you
have an antenna per band for bands such as 160-6M or more you can
accommodate them.
- There could be Bank A - which could have multiple banks to cover multiple
antennas to give you Bank A1, A2, A3, A4, etc.
- There could also be Bank B (and also C, D, etc.) which also could have a
set of antennas
- Using the K3 Ant1/Ant2 switch to control two antennas per band - Bank A
and Bank B. (This is the one feature that isn't available off the shelf, at
least I can't find it).
- Auto position so the programmed antenna for a particular band tracks the
K3 or multiple K3's.
- Manual position (on the Magic Box or on the PC screen) with indicators to
select and show which Bank (antenna) has been selected. The indicators can
be programmable for a particular antenna.
- An easy way to select antenna in a stack

Hey, maybe two KRC2's with a DIGIOUT1 interface controlling which KRC2 is
selected? That would take care of my needs.

73,
N2TK, Tony



-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Eric Swartz - WA6HHQ,
Elecraft
Sent: Wednesday, July 13, 2011 2:13 PM
To: [hidden email]
Subject: Re: [Elecraft] KPA500 and KAT500 Ports

I'd like to redirect this discussion to what is be desired for an
external antenna / rig switching add-on box for the K3/KPA500 and/or
KAT500.  This question may have been missed in my original posting (below).

 From that posting:

A much better solution for those needing more than two auto-selected
antennas is to use an external relay switch box, controlled by the
radio. This has the advantage of getting the cables, clutter, and
switching network off the desktop and either under the table or outside.

There are certainly a number of external antenna switches out there that
can do this, but if we offered something that was tightly integrated
with the K3 (and KPA500/KAT500) as a product, what features would be
desirable? (Number of antennas, rigs inputs, switching options etc.)

73, Eric WA6HHQ

---

www.elecraft.com


On 7/12/2011 3:34 PM, Eric Swartz - WA6HHQ, Elecraft wrote:

> Hi Gary,
>
> Having 4-5 RG8 antenna cables, plus the input cable, hanging out the
> back of the desktop ATU is both likely to pull the ATU off the desk, and
> will easily not fit in the box size we are planning. It also adds a lot
> of complexity and cost to the basic ATU in order to accommodate more
> connections with the needed isolation etc. We certainly do not want to
> price the ATU out of the range of most hams, or make it too large.
>
> Many of us use manual or automatic switches external to the amp / tuner
> to provide these functions.
>
> A much better solution for those needing more than two auto-selected
> antennas is to use an external relay switch box, controlled by the
> radio. This has the advantage of getting the cables, clutter, and
> switching network off the desktop and either under the table or outside.
> There are certainly a number of external antenna switches out there that
> can do this, but if we offered something that was tightly integrated
> with the K3 (and KPA500/KAT500) as a product, what features would be
> desirable? (Number of antennas, rigs inputs, switching options etc.)
>

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[AC7AC]

CONTENTS DELETED

The author has deleted this message.

[Frederick Atchley]

To all:

I'm enjoying this thread because it directly addresses my two greatest
concerns. First of course is human error. The second concern is connector
problems.

Elecraft has addressed the first by using kit options on the K3/P3/KPA500 so
that I'm more aware of the result of my actions, and also by the outstanding
communications interface between the K3/P3/KPA500 units.

Then there is the second concern of connector failure. Elecraft has
maximized the digital capabilities within the K3, thereby limiting that
cabling concerns. They have also created a fool proof RF path for TX/RX
(I.e. the KISS KPA500.)

Now, the Elecraft team has asked what features we would like on the upcoming
KAT500. Here are mine:

1/   Maintain the integration that exists between K3, P3 and KPA500. The
threat here is that if they try to placate those with max power amplifiers,
Elecraft would open Pandora's Box for problems not of their making. What's
going to stop the human error of slamming max power across an 8:1 SWR and
causing a KAT500 crispy-critter? This would drain company resources.

2/   Keep the KISS principle in the TX/RX path. I live in a restricted deed
area. About 80 percent of all new housing has restrictive CC&Rs. This limits
me to two stealthy wire antennas. Two RF outputs are fine with me. Why not
make a BASIC tuner with the OPTION of adding an expanded switching matrix?
That way I'm not paying for something I don't need.

Elecraft has created the awesome "K" line. It is based on a long line of
frugal, super effective capabilities. I hope that Elecraft will continue to
focus on THAT "K" line. Their forte is one baby step at a time . options,
options, options, .

 

73, Fred, K3#2241, P3#100, KPA500 #115

 

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