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KPA500 and KAT500 Ports

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Dick Dickinson

Re: KPA500 and KAT500 Ports

For remote.switching signal on the coax.

73,

Dick - KA5KKT

_____

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

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Don Wilhelm-4

Re: KPA500 and KAT500 Ports

In reply to this post by Eric Swartz - WA6HHQ

Eric,

To be totally versatile, I would think two antennas per band would have
to be available - and that means a total capability of 18 selections.
Yes, the band/antenna should be controlled by the K3, and a 9 position
remote switch on each of the KAT500 outputs should serve any need (a
maximum of 2 antennas per band).

That is a lot of connectors, but might be properly addressed by offering
4 outputs for each KAT500 output (8 total) that the user could configure
for the bands desired - similar to the KRC2 configurator application.
For those who need more, offer an additional 5 x 2 outputs as an option.

In my particular case, I have 8 feelines that would have to be handled.
1 for 160/80/40, another for 80/40. 1 for 60 meters, one for a 20/15/10
meter dipole, one for a 20/15/10 meter beam, one for 30/17/12 meter
dipole, one for an 80 through 10m vertical, and one for a 6 meter beam.

So just looking at the combinations and permutations, I would need to
configure each KAT500/SW output for the particular combination of bands
it would be used for, and my needs would likely not match those of
anyone else, so configuration of the bands active for any one output
connector would be needed.

I have tried arranging my switching automatically, and have given up
because it does not cover all situations I want. To make matters more
complex, I want to switch those feedlines to one of 3 transceivers in
the shack, and so I have 4 feedlines for 160 through 6 meters coming
into the shack to make that possible.

Good luck on satisfying even a majority with any one given solution
unless each output is configurable for any combination of bands.

73,
Don W3FPR

On 7/13/2011 2:13 PM, Eric Swartz - WA6HHQ, Elecraft wrote:

> 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.)
>>
> ______________________________________________________________
> Elecraft mailing list
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>
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Don Wilhelm-4

Re: KPA500 and KAT500 Ports

Whoops, I forgot about the multiband vertical - I need one of 3
antennas to be selected on several bands, not two as I mentioned.

How many antennas do you have for any one band? Rhetorical question,
but Eric might like to know if he is thinking about the switching
arrangement to follow the KAT500.

73,
Don W3FPR

On 7/13/2011 2:46 PM, Don Wilhelm wrote:

> Eric,
>
> To be totally versatile, I would think two antennas per band would have
> to be available - and that means a total capability of 18 selections.
> Yes, the band/antenna should be controlled by the K3, and a 9 position
> remote switch on each of the KAT500 outputs should serve any need (a
> maximum of 2 antennas per band).
>
> That is a lot of connectors, but might be properly addressed by offering
> 4 outputs for each KAT500 output (8 total) that the user could configure
> for the bands desired - similar to the KRC2 configurator application.
> For those who need more, offer an additional 5 x 2 outputs as an option.
>
> In my particular case, I have 8 feelines that would have to be handled.
> 1 for 160/80/40, another for 80/40. 1 for 60 meters, one for a 20/15/10
> meter dipole, one for a 20/15/10 meter beam, one for 30/17/12 meter
> dipole, one for an 80 through 10m vertical, and one for a 6 meter beam.
>
> So just looking at the combinations and permutations, I would need to
> configure each KAT500/SW output for the particular combination of bands
> it would be used for, and my needs would likely not match those of
> anyone else, so configuration of the bands active for any one output
> connector would be needed.
>
> I have tried arranging my switching automatically, and have given up
> because it does not cover all situations I want. To make matters more
> complex, I want to switch those feedlines to one of 3 transceivers in
> the shack, and so I have 4 feedlines for 160 through 6 meters coming
> into the shack to make that possible.
>
> Good luck on satisfying even a majority with any one given solution
> unless each output is configurable for any combination of bands.
>
> 73,
> Don W3FPR
>
> On 7/13/2011 2:13 PM, Eric Swartz - WA6HHQ, Elecraft wrote:
>> 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.)
>>>
>> ______________________________________________________________
>> 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
>>
> ______________________________________________________________
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>
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>

Ed Muns, W0YK

Re: KPA500 and KAT500 Ports

In reply to this post by Eric Swartz - WA6HHQ

1. At least eleven antenna ports: 6 primary bands 160-10, 3 WARC bands, 6
and 2 meters. All of these bands are possible with a K3.

2. At least two radio ports for SO2R, but more would be "nice".

3. Generalized ability to user-configure any antenna port to any band.
Example use cases are a tribander, a 40 meter dipole used on 15 meters and a
10 meter antenna used for 12 meters.

4. Maximum integration with the K3, KPA500, KAT500 and KRC2 as possible.

5. Remotable, for those who wish to mount it on a tower closer to the
antennas, with only the radio coaxes and control cable back to the operating
position.

Ed - W0YK

Eric, WA6HHQ, asked:

> 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.)

Jim Wiley-2

Re: KPA500 and KAT500 Ports

In reply to this post by Eric Swartz - WA6HHQ

Here's a thought. I was faced with the problem of having a fairly large
selection of HF antennas, and 3 operating stations. What to do?
After some thought, I decided to create a matrix-type switch that could
control 10 different antennas into any of 5 rigs, in any combination.
That equates to 50 different setups, not counting multiple feeds.

The controller also allows multiples, in that any antenna can be
connected to more than one rig, and any rig can be connected to more
than one antenna. This is occasionally useful for special receiving
situations or experimentation.

The controller features a locking function that works with my station
controller (the gadget that manages which rig is allowed to be "on air"
and which audio or keying source is delivered where, as well as audio
outputs from the associated receivers). The lockout function makes it
impossible to transmit into another rig, or cause any other similar
problem. If I could have my 'druthers, I would have integrated the
lockout function directly with the rigs themselves, but when it was
being built, very few rigs (if any) were available that could do this.
Modern rigs, such as the K3 could accommodate this, I think. I do have
to be careful and not key up a rig "internally" (using it's own transmit
function button). But there is a BIG red light that comes on to help
remind me. Only did that once, years ago, with a Kenwood TS-940S, but
that rig's input overload protector handled the fault with no other
apparent damage.

My version does have a small amount of cross-talk (about -50 dB) that a
somewhat better design could reduce further. Overall, the project was
extremely successful, and works better than I could have envisioned. It
uses a control-head + switch unit architecture (the actual matrix switch
is mounted away from the operating position). It was NOT cheap, but 20
years later is still performing flawlessly, so the cost per year
continues to decline. I was able to recoup some of the expense by
selling a hat-full of other coax switches - which by the way would drive
me crazy to operate as there never seemed to be the right combination
for all the different setups I wanted to use.

I did NOT attempt to create something that would perform at VHF and
above. My switch is strictly a HF/MF device. The insertion loss is
on the order of 0.5 dB or less, depending on band. Measured VSWR, last
time I looked, tends to stay below 1.25:1 on any frequency or equipment
combination, except of course for multiple connections. Not perfect,
but good enough. An antenna coupler makes what minor corrections are
needed, if I were to care about such things, which usually I don't.
Getting that last little bit of SWR out is not worth the trouble,
usually, particularly at HF. VHF and above is different. Handles 1500
watts with ease.

- Jim, KL7CC

.

Eric Swartz - WA6HHQ, Elecraft wrote:
> 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.
>
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Craig Smith

Re: KPA500 and KAT500 Ports

In reply to this post by Ed Muns, W0YK

As a general answer, I think 4 ports per band would be sufficient for most
of us.

But by that I mean 4 "antenna selections" per band. Some of these would be
multiband antennas that are used on more than one band and only need one
connector to the switching network. Balanced output connections should be
available as well as UHF connectors for unbalanced loads.

If Elecraft decides to make an enclosed network that includes output
connectors, I would still like to see a few relay driver outputs available
for further customization by the user. One example is that I need to switch
the ladderline feed on my doublet so that the two conductors are shorted
together and fed against ground as a Marconi on the low bands. This can
easily be done with external relay(s) if drivers are provided.

I also very much like the idea of a "bare" KAT500 option with a host of
relay drivers. The user could then build their own enclosure with a
suitable number and types of connectors and relays. Other custom
configuration chores, such as mentioned in the previous paragraph, could
also be accommodated with this approach. Of course the user would need to
provide a suitable enclosure and weatherproofing.

73 Craig AC0DS

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Eric Swartz - WA6HHQ

Re: KPA500 and KAT500 Ports

Administrator

Guys - Please reply just to the list. I am getting two of each reply. :-)

73, Eric

---
www.elecraft.com

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Bob-270

Re: KPA500 and KAT500 Ports

In reply to this post by Eric Swartz - WA6HHQ

Hi,

That could be a unit that fits well with the Elecraft concept of a basic
kit with the ability to expand as needed with options. Since most of the parts
for a unit of this type will be human sized it could even make those that like
the smell of rosin happy.

If the unit was sold as say a basic, one in with three or four outputs it
could be made expandable. The box could be pre punched with knockouts like
electrical boxes or have hole plugs. The "kits" of parts might be marketed to
add inputs or outputs onto the main PCB. Broadcast Xmitters run some pretty
high power modules. I'll not get into costs but if not prohibitive maybe an
input/output add on module concept might be doable.

No box will do it all, but an expandable concept might just expand the
marketing possibilities too.

Whatever it ends up doing I'm sure it will do it well.

For statistical purposes 2 in and 4 out would cover my 160 to 6 needs now
and for the foreseeable future. Remote ability would be a high priority if
for no other reason than putting the cabling (mess) out in the garage out of
the way.

73,
Bob
K2TK ex KN2TKR (1956) & K2TKR

On 7/13/2011 2:13 PM, Eric Swartz - WA6HHQ, Elecraft wrote:

Andrew Moore-3

Re: KPA500 and KAT500 Ports

In reply to this post by Eric Swartz - WA6HHQ

My needs are simple. I'd vote for a simpler, lower-cost box which is
expandable by way of relays, external box, etc. 2-4 outputs is fine by me.
I think a simpler, expandable box that could be used by more users is
preferable (from a user standpoint as well as a biz standpoint) to a more
targeted, higher cost one.

Besides, then you can come out with another great product later :)

--Andrew, NV1B
..
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Jim Brown-10

Re: KPA500 and KAT500 Ports

In reply to this post by Ed Muns, W0YK

I think Ed has articulated exactly what I need, but a lot more than what
most users need. I was just counting HF TX antennas and came up with a
total of 11, and have plans to add two or three more this summer. In the
pro audio world, we do a lot with things that can be modularly expanded
to fit various system configurations. Perhaps a 6x2 unit with that
capability would work well.

Also, I have set up my station so that I can switch between two power
amps for each radio -- a KPA500 and a legal limit tube amp. The KPA
gives me instant on and 6M with minimal shack heating and low
electricity cost, and the tube amp is for serious contesting, or when I
need the extra 4 dB to get over noise on the other end.

73, Jim K9YC

On 7/13/2011 12:05 PM, Ed Muns wrote:

> 1. At least eleven antenna ports: 6 primary bands 160-10, 3 WARC bands, 6
> and 2 meters. All of these bands are possible with a K3.
>
> 2. At least two radio ports for SO2R, but more would be "nice".
>
> 3. Generalized ability to user-configure any antenna port to any band.
> Example use cases are a tribander, a 40 meter dipole used on 15 meters and a
> 10 meter antenna used for 12 meters.
>
> 4. Maximum integration with the K3, KPA500, KAT500 and KRC2 as possible.
>
> 5. Remotable, for those who wish to mount it on a tower closer to the
> antennas, with only the radio coaxes and control cable back to the operating
> position.
>
> Ed - W0YK

Bill Steffey NY9H

Re: KPA500 and KAT500 Ports

i have 5 hf ants available to two radios..l...k3 & icom plus a third
output on the panel... use top ten devices a/b boxes ( lots of isolation)...
plus also allow whichever is the main radio to select from two amps...
my old herc II instant on and my legal bigger box....

none was automated
so far no smoke,.,,,\\

now that i just assembled my kpa500 ..... do i sell my 12 volt herc ?????
...probably not....

bill ny9h/3

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Larry stowell

Re: KPA500 and KAT500 Ports

In reply to this post by Jim Wiley-2

To all
Look at Kessler Engineering' CX-Auto (and add on for the AT-Auto Palstar) 8 outputs controlled by
the tuner. Or remember back to the Alpha DAS controlled by the 87A and 3rd party relay boxes, up to
36 antennas.

I agree with Eric get the cables out of the shack.

73 Larry K1ZW

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Brendan Minish

Re: KPA500 and KAT500 Ports

In reply to this post by Eric Swartz - WA6HHQ

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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Bill K9YEQ

Re: KPA500 and KAT500 Ports

In reply to this post by Eric Swartz - WA6HHQ

Eric,

I have two feed lines to my "farm". I use a CAT5 cable to my switch in the
back yard. An Ameritron RCS-8V is the remote switch. I have another 2 line
power cable to a remote tuner to allow use of these antennas. I currently
have to use the switching to disconnect the antennas to ground at the remote
site. I also use in shack switching to ground the antennas when I am not
using them. I do not have the KPA500 and use the THP 2.5kfx. I need to
switch remotely and tune as well. I use the W2 to monitor SWR and switch
out the amp if SWR runs too high. This is an issue when trying to tune. I
do this using lower power first.

I would like to simplify all of this so when you get past the in-shack tuner
and move on to remote design, I would like help to resolve these issues via
software and control in the shack. Hope this is not too tall an order. :-)
(Oh, I would like use my K2 and TS2000 in this system as well with most of
the switching to be automated.)

73,
Bill
K9YEQ

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Eric Swartz - WA6HHQ,
Elecraft
Sent: Wednesday, July 13, 2011 1:13 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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Eric Swartz - WA6HHQ

Re: KPA500 and KAT500 Ports

Administrator

In reply to this post by Brendan Minish

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

Joe Subich, W4TV-4

Re: KPA500 and KAT500 Ports

In reply to this post by Brendan Minish

I admit, I have a dog in this fight but I see the calls for all manner
of add-on antenna switching hardware for the KAT-500, and/or KPA-500
as more than a little lily gilding ... and too much cost/effort for
very little benefit.

1) antenna switches *after* a tuner are problematic to start with.
The switch/relay needs to be designed to handle a substantial
excess voltage and excess current if it is to be reliable at
high SWR. Some of that can be mitigated by limiting the power
levels (e.g., 600 W from the KPA-500) but I've already seen posts
where US stations want to be able to handle their "legal limit"
amplifiers.

Realistically, at even 3:1 SWR that a couple KV and/or nearly 10A
on peaks. Relays to handle those levels with good impedance match
and reliability don't come cheap.

2) there is no way that any antenna switching logic built into the
K3, KPA-500 or KAT-500 can provide switching for multiple antennas
per band ... perhaps the ANT1/ANT2 logic of the K3 can be hijacked
*IF* the second antenna port of the KAT-3 is disabled but that
still limits the choice to two - not three or more antennas as
some have expressed a "need" for.

3) there are another group that express a need for "matrix" switch
capability ... to be able to select and route multiple antennas
to multiple transceivers, possibly with the option to select one
amplifier for each transceiver from among a pool of amplifiers.

4) adding the ability to switch any of several antennas to either
of two antenna ports or the K3 or KAT-500 is a prime example
of lily gilding ... particularly since both antenna ports are
not used at the same time. However, that switching capability
is already available in "SO2R" antenna switches from several
sources - it only takes a little bit of decoding the K3 DIGOUT1
and band data lines if one were so inclined.

All of these, and other "wants" are nice on their own but not as a
"standard" capability for the K-line. Most of the wants can/should
be satisfied with already announced/available products that deal
with antenna switching/station management. After all, these are
system integration items/issues that are not specific to the K3,
KAT-500 or KPA-500 ... integrating the capability into those products
increases their cost for all users *and* limits the use of those
capabilities to those with the Elecraft specific hardware. Any good
businessman will tell you that increasing cost and limiting the
market are a bad combination ...

Much of this reminds me of someone trying to renovate a kitchen in
the morning and restore a classic car in the afternoon and expecting
Craftsman or Kobalt to provide them a single "Swiss army knife" with
all of the tools to do both jobs. It's neither practical nor logical.

73,

... Joe, W4TV

On 7/13/2011 7:22 PM, Brendan Minish wrote:

Jeff Cochrane - VK4XA

Re: KPA500 and KAT500 Ports

In reply to this post by Eric Swartz - WA6HHQ

CONTENTS DELETED

The author has deleted this message.

Oscar, WB5GCX

Re: KPA500 and KAT500 Ports

Good summary, Jeff.

I'd like to also emphasize that there are a good number of us out here with
deed restriction/covenant situations that have to use a single HF antenna
(175' inverted "L" here) with an external, outdoor tuner. We are all waiting
for an "external" option or version of the KAT-500.

In my case, I currently use the SGC-230 which limits me to about 60 watts
cw, and 200 watts SSB. There's no reason for me to purchase the KPA-500
until I can replace the low power external tuner with something capable of
500+ watts.

I'll continue to patiently wait. My KX-1, K3, and P3 are wonderful. I'm
sure the KAT-500 will also be worth the wait.

Oscar, WB5GCX

On Wed, Jul 13, 2011 at 9:31 PM, Jeff Cochrane - VK4BOF <
[hidden email]> 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....
>
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Gary Gregory

Re: KPA500 and KAT500 Ports

Want's ALWAYS exceed the Need...:-)

Gary

On 14 July 2011 13:10, Oscar Staudt <[hidden email]> wrote:

> Good summary, Jeff.
>
> I'd like to also emphasize that there are a good number of us out here with
> deed restriction/covenant situations that have to use a single HF antenna
> (175' inverted "L" here) with an external, outdoor tuner. We are all
> waiting
> for an "external" option or version of the KAT-500.
>
> In my case, I currently use the SGC-230 which limits me to about 60 watts
> cw, and 200 watts SSB. There's no reason for me to purchase the KPA-500
> until I can replace the low power external tuner with something capable of
> 500+ watts.
>
> I'll continue to patiently wait. My KX-1, K3, and P3 are wonderful. I'm
> sure the KAT-500 will also be worth the wait.
>
> Oscar, WB5GCX
>
> On Wed, Jul 13, 2011 at 9:31 PM, Jeff Cochrane - VK4BOF <
> [hidden email]> 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....
> >
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

--

VK4FD - Motorhome Mobile
Elecraft Equipment
K3 #679, KPA-500 #018
Living the dream!!!
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Tony Estep

Re: KPA500 and KAT500 Ports

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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