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Looking for a way to switch an antenna input to the KAT500

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Tom-4

Looking for a way to switch an antenna input to the KAT500

Hi,
I use a Kat500 with my K3 and KX3. However, I have a number of other radios which I would like to use with the Kat500. So I'm looking for a antenna switch that can change inputs in some way based on an electronic signal. The signal can be via serial device, or network doesn't matter. Anyone know of such a programmable switch?
Thanks, Tom
Va2fsq.com

-----Original Message-----
From: [hidden email] <[hidden email]> On Behalf Of Bob McGraw K4TAX
Sent: February 17, 2019 3:06 PM
To: [hidden email]
Subject: Re: [Elecraft] Coax Switches

Smart man and decisions and the way to do things correctly. Glad to see this.

73

Bob, K4TAX

On 2/17/2019 9:38 AM, James F. Boehner MD via Elecraft wrote:

> I use the Alpha Delta Series. They have SO-239 and "N" connector models, two position or four position. For the price difference, I always get four position.
>
> They are not only well built switches, but they do have surge protection (gas) with a replaceable pill. Their best feature is the very high isolation they offer:
>
> 30 MHz >60 dB
> 150 MHz >50 dB
> 450 MHz 50 dB
>
> And dB Loss:
>
> 30 MHz 0.1 dB
> 150 MHz 0.15 dB
> 450 MHz 0.5 dB
>
> So, I wish these could be remotable. However, they are the best switches I've found for a reasonable price, and I have many of them in my station.
>
> Oh yes, on the outside of my house, I have polyphasers.
>
> '73 de JIM N2ZZ
>
>
>
> I do use a number of Daiwa 2-position coax switches for various
> purposes. Any comments on coax switches?
>
> Bill W2BLC K-Line
>
>

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W2xj

Re: Looking for a way to switch an antenna input to the KAT500

https://www.dowkey.com/product-category/coaxial-switches/

Sent from my iPad

> On Feb 17, 2019, at 3:30 PM, Tom <[hidden email]> wrote:
>
> Hi,
> I use a Kat500 with my K3 and KX3. However, I have a number of other radios which I would like to use with the Kat500. So I'm looking for a antenna switch that can change inputs in some way based on an electronic signal. The signal can be via serial device, or network doesn't matter. Anyone know of such a programmable switch?
> Thanks, Tom
> Va2fsq.com
>
> -----Original Message-----
> From: [hidden email] <[hidden email]> On Behalf Of Bob McGraw K4TAX
> Sent: February 17, 2019 3:06 PM
> To: [hidden email]
> Subject: Re: [Elecraft] Coax Switches
>
> Smart man and decisions and the way to do things correctly. Glad to see this.
>
> 73
>
> Bob, K4TAX
>
>
>> On 2/17/2019 9:38 AM, James F. Boehner MD via Elecraft wrote:
>> I use the Alpha Delta Series. They have SO-239 and "N" connector models, two position or four position. For the price difference, I always get four position.
>>
>> They are not only well built switches, but they do have surge protection (gas) with a replaceable pill. Their best feature is the very high isolation they offer:
>>
>> 30 MHz >60 dB
>> 150 MHz >50 dB
>> 450 MHz 50 dB
>>
>> And dB Loss:
>>
>> 30 MHz 0.1 dB
>> 150 MHz 0.15 dB
>> 450 MHz 0.5 dB
>>
>> So, I wish these could be remotable. However, they are the best switches I've found for a reasonable price, and I have many of them in my station.
>>
>> Oh yes, on the outside of my house, I have polyphasers.
>>
>> '73 de JIM N2ZZ
>>
>>
>>
>> I do use a number of Daiwa 2-position coax switches for various
>> purposes. Any comments on coax switches?
>>
>> Bill W2BLC K-Line
>>
>>
>
> ______________________________________________________________
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Elecraft mailing list

Re: Looking for a way to switch an antenna input to the KAT500

In reply to this post by Tom-4

TopTen has a nice A/B switch with pretty good isolation characteristics. See: https://toptendevices.com/products/ab-station-selector/ <https://toptendevices.com/products/ab-station-selector/>
It requires a 12V signal for switching, I believe.

Array Solutions also sells some devices that may be of interest.

73!
Jack, W6fB

> On Feb 17, 2019, at 12:30 PM, Tom <[hidden email]> wrote:
>
> Hi,
> I use a Kat500 with my K3 and KX3. However, I have a number of other radios which I would like to use with the Kat500. So I'm looking for a antenna switch that can change inputs in some way based on an electronic signal. The signal can be via serial device, or network doesn't matter. Anyone know of such a programmable switch?
> Thanks, Tom
> Va2fsq.com
>
> -----Original Message-----
> From: [hidden email] <[hidden email]> On Behalf Of Bob McGraw K4TAX
> Sent: February 17, 2019 3:06 PM
> To: [hidden email]
> Subject: Re: [Elecraft] Coax Switches
>
> Smart man and decisions and the way to do things correctly. Glad to see this.
>
> 73
>
> Bob, K4TAX
>
>
> On 2/17/2019 9:38 AM, James F. Boehner MD via Elecraft wrote:
>> I use the Alpha Delta Series. They have SO-239 and "N" connector models, two position or four position. For the price difference, I always get four position.
>>
>> They are not only well built switches, but they do have surge protection (gas) with a replaceable pill. Their best feature is the very high isolation they offer:
>>
>> 30 MHz >60 dB
>> 150 MHz >50 dB
>> 450 MHz 50 dB
>>
>> And dB Loss:
>>
>> 30 MHz 0.1 dB
>> 150 MHz 0.15 dB
>> 450 MHz 0.5 dB
>>
>> So, I wish these could be remotable. However, they are the best switches I've found for a reasonable price, and I have many of them in my station.
>>
>> Oh yes, on the outside of my house, I have polyphasers.
>>
>> '73 de JIM N2ZZ
>>
>>
>>
>> I do use a number of Daiwa 2-position coax switches for various
>> purposes. Any comments on coax switches?
>>
>> Bill W2BLC K-Line
>>
>>
>
> ______________________________________________________________
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>
>
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John Simmons

Re: Looking for a way to switch an antenna input to the KAT500

Jack,

Thanks for bringing this to my attention... it is just what I have been
looking for to switch between my main and remote operated stations!

73,
-John NI0K

> Jack Brindle via Elecraft <mailto:[hidden email]>
> Sunday, February 17, 2019 3:59 PM
> TopTen has a nice A/B switch with pretty good isolation
> characteristics. See:
> https://toptendevices.com/products/ab-station-selector/
> <https://toptendevices.com/products/ab-station-selector/>
> It requires a 12V signal for switching, I believe.
>
> Array Solutions also sells some devices that may be of interest.
>
> 73!
> Jack, W6fB
>
>
> ______________________________________________________________
> 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
> Message delivered to [hidden email]
> Tom <mailto:[hidden email]>
> Sunday, February 17, 2019 2:30 PM
> Hi,
> I use a Kat500 with my K3 and KX3. However, I have a number of other
> radios which I would like to use with the Kat500. So I'm looking for a
> antenna switch that can change inputs in some way based on an
> electronic signal. The signal can be via serial device, or network
> doesn't matter. Anyone know of such a programmable switch?
> Thanks, Tom
> Va2fsq.com
>
> -----Original Message-----
> From: [hidden email]
> <[hidden email]> On Behalf Of Bob McGraw K4TAX
> Sent: February 17, 2019 3:06 PM
> To: [hidden email]
> Subject: Re: [Elecraft] Coax Switches
>
> Smart man and decisions and the way to do things correctly. Glad to
> see this.
>
> 73
>
> Bob, K4TAX
>
>
> ______________________________________________________________
> 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
> Message delivered to [hidden email]
>
>
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Tom-4

Re: Looking for a way to switch an antenna input to the KAT500

In reply to this post by Elecraft mailing list

Hi,

Yes this looks interesting as does the ones from Dewey. It seems that top
ten devices also has a 6 antenna to 1 radio switch. Anyone know if it can
operate the other way around? 6 radios to one antenna (kat500)?

73 Tom

From: John Simmons <[hidden email]>
Sent: February 17, 2019 5:10 PM
To: Jack Brindle <[hidden email]>
Cc: Tom <[hidden email]>; [hidden email]
Subject: Re: [Elecraft] Looking for a way to switch an antenna input to the
KAT500

Jack,

Thanks for bringing this to my attention... it is just what I have been
looking for to switch between my main and remote operated stations!

73,
-John NI0K

Jack Brindle via Elecraft <mailto:[hidden email]>

Sunday, February 17, 2019 3:59 PM

TopTen has a nice A/B switch with pretty good isolation characteristics.
See: https://toptendevices.com/products/ab-station-selector/
<https://toptendevices.com/products/ab-station-selector/>
<https://toptendevices.com/products/ab-station-selector/>
It requires a 12V signal for switching, I believe.

Array Solutions also sells some devices that may be of interest.

73!
Jack, W6fB

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<mailto:[hidden email]>

Tom <mailto:[hidden email]>

Sunday, February 17, 2019 2:30 PM

Hi,
I use a Kat500 with my K3 and KX3. However, I have a number of other radios
which I would like to use with the Kat500. So I'm looking for a antenna
switch that can change inputs in some way based on an electronic signal. The
signal can be via serial device, or network doesn't matter. Anyone know of
such a programmable switch?
Thanks, Tom
Va2fsq.com

-----Original Message-----
From: [hidden email]
<mailto:[hidden email]>
<mailto:[hidden email]> <[hidden email]>
On Behalf Of Bob McGraw K4TAX
Sent: February 17, 2019 3:06 PM
To: [hidden email] <mailto:[hidden email]>
Subject: Re: [Elecraft] Coax Switches

Smart man and decisions and the way to do things correctly. Glad to see
this.

73

Bob, K4TAX

______________________________________________________________
Elecraft mailing list
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Help: http://mailman.qth.net/mmfaq.htm
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Randy Farmer

Re: Looking for a way to switch an antenna input to the KAT500

I concur with the comments on the Top Ten 2-way switches. I'm using
about 10 of them at various places in my SO2R contest station antenna
and BPF switching networks. They work well and have good isolation. I'm
also using a 6-way for RX antenna switching. It's simply one port
switched to one of six, so it will work just fine either way. RF doesn't
care which way it goes through relays. A nice benefit of the Top Ten
switches is that they're internally interlocked, so it's electrically
impossible to select more than one port-to-port configuration at a time.

73...
Randy, W8FN

On 2/17/2019 6:55 PM, Tom wrote:

> Hi,
>
> Yes this looks interesting as does the ones from Dewey. It seems that top
> ten devices also has a 6 antenna to 1 radio switch. Anyone know if it can
> operate the other way around? 6 radios to one antenna (kat500)?
>
> 73 Tom
>
>
>
> From: John Simmons <[hidden email]>
> Sent: February 17, 2019 5:10 PM
> To: Jack Brindle <[hidden email]>
> Cc: Tom <[hidden email]>; [hidden email]
> Subject: Re: [Elecraft] Looking for a way to switch an antenna input to the
> KAT500
>
>
>
> Jack,
>
> Thanks for bringing this to my attention... it is just what I have been
> looking for to switch between my main and remote operated stations!
>
> 73,
> -John NI0K
>
>
>
>
> Jack Brindle via Elecraft <mailto:[hidden email]>
>
> Sunday, February 17, 2019 3:59 PM
>
> TopTen has a nice A/B switch with pretty good isolation characteristics.
> See: https://toptendevices.com/products/ab-station-selector/
> <https://toptendevices.com/products/ab-station-selector/>
> <https://toptendevices.com/products/ab-station-selector/>
> It requires a 12V signal for switching, I believe.
>
> Array Solutions also sells some devices that may be of interest.
>
> 73!
> Jack, W6fB
>
>
> ______________________________________________________________
> 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
> Message delivered to [hidden email]
> <mailto:[hidden email]>
>
> Tom <mailto:[hidden email]>
>
> Sunday, February 17, 2019 2:30 PM
>
> Hi,
> I use a Kat500 with my K3 and KX3. However, I have a number of other radios
> which I would like to use with the Kat500. So I'm looking for a antenna
> switch that can change inputs in some way based on an electronic signal. The
> signal can be via serial device, or network doesn't matter. Anyone know of
> such a programmable switch?
> Thanks, Tom
> Va2fsq.com
>
> -----Original Message-----
> From: [hidden email]
> <mailto:[hidden email]>
> <mailto:[hidden email]> <[hidden email]>
> On Behalf Of Bob McGraw K4TAX
> Sent: February 17, 2019 3:06 PM
> To: [hidden email] <mailto:[hidden email]>
> Subject: Re: [Elecraft] Coax Switches
>
> Smart man and decisions and the way to do things correctly. Glad to see
> this.
>
> 73
>
> Bob, K4TAX
>
>
> ______________________________________________________________
> 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 Message
> delivered to [hidden email] <mailto:[hidden email]>
>
>
> ---
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>
>
>
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>

Jim Brown-10

Re: Looking for a way to switch an antenna input to the KAT500

On 2/17/2019 6:26 PM, Randy Farmer wrote:
> I concur with the comments on the Top Ten 2-way switches. I'm using
> about 10 of them at various places in my SO2R contest station antenna
> and BPF switching networks. They work well and have good isolation. I

On the basis of my measurements with a Vector Network Analyzer, I am NOT
impressed with these switches, and consider them poorly designed. The
major design flaw is that they depend upon the chassis for signal
return, so the signal path gets increasingly badly mismatched at 15M and
above. I didn't measure crosstalk, but this design error would certainly
impact it. I reduced the mismatch by about half by adding braid from the
coax connectors to the circuit board and following (as best I could) the
signal path to provide a return. Why? Because the "ground" layer is
broken under the top layer, so it can't act as a return either!

Someone cited 50 dB as "good isolation." When I replaced my WX0B 6x2, I
measured isolation of about 55 dB. The replacement, a 4O3A 6x2, measured
75 dB worst case. And other one I'm using now, the 4O3A Antenna Genius,
measures better than 95 dB worst case.

If you look inside a well designed power amp, you'll see transmission
line running from input and output for both TX and RX path. My Ten Tec
Titans were built that way, and so is the KPA500. You'll also see
mini-coax jumpers tying sections of the K3 together.

73, Jim K9YC

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Randy Farmer

Re: Looking for a way to switch an antenna input to the KAT500

Yup, I did specify "good", not "great" isolation for the Top Ten
switches. I'm aware of their limitations. I agree that it's always
desirable to have 70+ dB port-to-port isolation if you can get it (and
afford it), but depending on the application it's certainly not always
necessary. During the phase of my career when I was involved in cellular
base station RF system design, in which performance was always balanced
with cost (and guess which one won if push came to shove), I learned to
do balanced designs that made sure no component was over-specified. This
experience has carried through to my HF station design.

In my particular case, I'm switching TX bandpass filters that supplement
the main BPF at the output of the radio to suppress harmonics and noise
from the amplifier. There's a pair of the Top Ten 2-ways at the input
and output ports of the TX BPF bank that lets me share a single bank of
filters between two radios. The filter banks are switched by a 2X6
switch matrix at each end that has around 60 dB port-to-port isolation.
The bandpass filters themselves have about 80 dB worst case adjacent
band isolation, so assuming the I/O switches each have 60 dB or so of
isolation, that's theoretically -120 dB leakage contributed by the
selector switches. This leakage is thus about 40 dB down from the worst
case BPF rejection, therefore negligible.Even if the total switch
isolation were only 80dB, this would mean the additional power
contributed from switch leakage would increase the total coupling (and
therefore decrease the isolation) by only 3 dB. The 2-way switches are
used to either enable the TX filter bank for the contest bands or bypass
it for the WARC bands. So putting a 2-way switch with mediocre isolation
on each I/O port of the selector switches has no effect on system
performance in the contest bands. Actually, even though the whole
network is wired with LMR-240 the coax shielding is probably the
limiting factor for total station-to-station isolation anyhow. I agree
that there are places where excellent isolation is required, and should
be specified. Like you, I used to use a WX0B SixPak, but many years ago
I replaced with a microHAM Double Ten switch, which has isolation
similar to the 4O3A switch, for this reason.

As for VSWR effects, I've learned long ago that attempting to make
complex RF systems involving filters and multiple switching points over
the almost 4 octaves of the HF to 6 meter range look like 50 + j0 on
every band is an essentially impossible endeavor. Fortunately,
well-designed transmitters these days are not overly sensitive to
moderate VSWR loads; as long as there's not a really bad mismatch
somewhere in the system they should take normal mismatches in stride.

The OP was inquiring about switches that are suitable to switch multiple
radios to one amplifier input, which implies that only one radio at a
time will be active. For that the Top Ten switches are plenty good enough.

73...
Randy, W8FN

On 2/17/2019 8:57 PM, Jim Brown wrote:

> On 2/17/2019 6:26 PM, Randy Farmer wrote:
>> I concur with the comments on the Top Ten 2-way switches. I'm using
>> about 10 of them at various places in my SO2R contest station antenna
>> and BPF switching networks. They work well and have good isolation. I
>
> On the basis of my measurements with a Vector Network Analyzer, I am
> NOT impressed with these switches, and consider them poorly designed.
> The major design flaw is that they depend upon the chassis for signal
> return, so the signal path gets increasingly badly mismatched at 15M
> and above. I didn't measure crosstalk, but this design error would
> certainly impact it. I reduced the mismatch by about half by adding
> braid from the coax connectors to the circuit board and following (as
> best I could) the signal path to provide a return. Why? Because the
> "ground" layer is broken under the top layer, so it can't act as a
> return either!
>
> Someone cited 50 dB as "good isolation." When I replaced my WX0B 6x2,
> I measured isolation of about 55 dB. The replacement, a 4O3A 6x2,
> measured 75 dB worst case. And other one I'm using now, the 4O3A
> Antenna Genius, measures better than 95 dB worst case.
>
> If you look inside a well designed power amp, you'll see transmission
> line running from input and output for both TX and RX path. My Ten Tec
> Titans were built that way, and so is the KPA500. You'll also see
> mini-coax jumpers tying sections of the K3 together.
>
> 73, Jim K9YC

john@kk9a.com

Re: Looking for a way to switch an antenna input to the KAT500

In reply to this post by Tom-4

W2VJN and N3RD from Top Ten Devices are great helpful guys. I have been
using their band decoders for decades and we have both operated from the
same station in St Croix. I also have a Top Ten 6 way antenna relay box
that I only use only on contest expeditions with a single radio. It is
small, light weight and easily fits in my suitcase. This is not a
heavy-duty relay, you cannot run legal limit RTTY though it. Also the
SO-239 center connectors are recessed which might cause an issue with some
crimped PL-259's. To use their relays for an SO2R station would require a
lot of relay boxes and they claim isolation >40dB. For me a single 2 x 6
box is a better choice, Array Solutions SixPak claims >55dB which Jim
confirmed.

John KK9A

Jim Brown K9YC wrote:
On 2/17/2019 6:26 PM, Randy Farmer wrote:
> I concur with the comments on the Top Ten 2-way switches. I'm using
> about 10 of them at various places in my SO2R contest station antenna
> and BPF switching networks. They work well and have good isolation. I

On the basis of my measurements with a Vector Network Analyzer, I am NOT
impressed with these switches, and consider them poorly designed. The
major design flaw is that they depend upon the chassis for signal
return, so the signal path gets increasingly badly mismatched at 15M and
above. I didn't measure crosstalk, but this design error would certainly
impact it. I reduced the mismatch by about half by adding braid from the
coax connectors to the circuit board and following (as best I could) the
signal path to provide a return. Why? Because the "ground" layer is
broken under the top layer, so it can't act as a return either!

Someone cited 50 dB as "good isolation." When I replaced my WX0B 6x2, I
measured isolation of about 55 dB. The replacement, a 4O3A 6x2, measured
75 dB worst case. And other one I'm using now, the 4O3A Antenna Genius,
measures better than 95 dB worst case.

If you look inside a well designed power amp, you'll see transmission
line running from input and output for both TX and RX path. My Ten Tec
Titans were built that way, and so is the KPA500. You'll also see
mini-coax jumpers tying sections of the K3 together.

73, Jim K9YC

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