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RX antenna & carrier-operated relay

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Fabio IZ4AFW / NZ1W

RX antenna & carrier-operated relay

Hi guys,
I was thinking of a possible firmware improvement related to the
carrier operated relay.
I use my radio on a small lot and recently I added a short beverage
antenna for low-bands receiving. My main activity is single-op contesting.
Because of the interaction between the tx antennas and the beverage, on
some bands I have the COR (carrier operated relay) activating when I use
high power.
I know the good solutions, but my point is different.
As I have the COR activating only when the RX Ant input is selected, why
doesn't the K3 firmware disable it when pushing the ptt?

In fact, when I push the ptt I don't need the RX-ant part to be active,
as I'm transmitting, and -at least in my setup- I have no other
rigs/devices that need that input (I mean, no in-band receivers and so on).
Instead of using external relays (ptt-activated) that cut out the rx
input when I am transmitting, why the K3 firmware just doesn't disable
the RX ant input on its own (and re-enables it if needed when releasing
the ptt)?
Maybe I'm missing something here, or that could be a nice improvement
for a next firmware release.

Thanks for any comment,
Ciao 73
Fabio
IZ4AFW / IO4W / NZ1W

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David Olean

Re: RX antenna & carrier-operated relay

Hello Fabio

I have two beverages that are somewhat close to my TX antenna. One
had about 75 mw on it during TX while beverage #2 had about 1 watt! This
is enough power to cause damage to preamps, so I made two power limiters
and now the inputs are clipped at about 0 dBm. All it took was two
transformers and two diodes in a box. Do you know what the power level
is on your beverage during transmit periods? Really high power levels
could burn up the transformers. Disconnecting the antenna is a good
idea too.

Dave K1WHS

On 3/4/2017 9:53 AM, Fabio IZ4AFW / NZ1W wrote:

> Hi guys,
> I was thinking of a possible firmware improvement related to the
> carrier operated relay.
> I use my radio on a small lot and recently I added a short beverage
> antenna for low-bands receiving. My main activity is single-op contesting.
> Because of the interaction between the tx antennas and the beverage, on
> some bands I have the COR (carrier operated relay) activating when I use
> high power.
> I know the good solutions, but my point is different.
> As I have the COR activating only when the RX Ant input is selected, why
> doesn't the K3 firmware disable it when pushing the ptt?
>
> In fact, when I push the ptt I don't need the RX-ant part to be active,
> as I'm transmitting, and -at least in my setup- I have no other
> rigs/devices that need that input (I mean, no in-band receivers and so on).
> Instead of using external relays (ptt-activated) that cut out the rx
> input when I am transmitting, why the K3 firmware just doesn't disable
> the RX ant input on its own (and re-enables it if needed when releasing
> the ptt)?
> Maybe I'm missing something here, or that could be a nice improvement
> for a next firmware release.
>
> Thanks for any comment,
> Ciao 73
> Fabio
> IZ4AFW / IO4W / NZ1W
>
>
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Jessie Oberreuter-2

Re: RX antenna & carrier-operated relay

In reply to this post by Fabio IZ4AFW / NZ1W

The 2nd Rx port is on a relay, and not a particularly fast or quiet
one in my K3. I'd hate to operate QSK that way! I could see a menu
option that would activate it with a longer hang time, but you'd probably
be better off with an external switch and/or front-end protector. -kb7psg

On Sat, 4 Mar 2017, Fabio IZ4AFW / NZ1W wrote:

Fabio IZ4AFW / NZ1W

Re: RX antenna & carrier-operated relay

In reply to this post by David Olean

Hi Dave,
thanks for the suggestion.
I tried doing a quick measure using a cross-needle SWR meter today,
using the lowest setting.
On 40m the power appears to just deflect the needle, well below the 0.5W
mark. Probably I could say less than 250mW, maybe 100mW.
I usually have an external relay in a box to disconnect the RX antennas
while transmitting, but not today.
I was thinking why the RX antennas remain connected when transmitting if
there's not another use in a typical single-op station.

Thanks,
Ciao
Fabio
IZ4AFW / IO4W / NZ1W

Il 04.03.2017 13:12, David Olean ha scritto:

> Hello Fabio
>
> I have two beverages that are somewhat close to my TX antenna. One
> had about 75 mw on it during TX while beverage #2 had about 1 watt! This
> is enough power to cause damage to preamps, so I made two power limiters
> and now the inputs are clipped at about 0 dBm. All it took was two
> transformers and two diodes in a box. Do you know what the power level
> is on your beverage during transmit periods? Really high power levels
> could burn up the transformers. Disconnecting the antenna is a good
> idea too.
>
> Dave K1WHS
>
>
> On 3/4/2017 9:53 AM, Fabio IZ4AFW / NZ1W wrote:
>> Hi guys,
>> I was thinking of a possible firmware improvement related to the
>> carrier operated relay.
>> I use my radio on a small lot and recently I added a short beverage
>> antenna for low-bands receiving. My main activity is single-op
>> contesting.
>> Because of the interaction between the tx antennas and the beverage, on
>> some bands I have the COR (carrier operated relay) activating when I use
>> high power.
>> I know the good solutions, but my point is different.
>> As I have the COR activating only when the RX Ant input is selected, why
>> doesn't the K3 firmware disable it when pushing the ptt?
>>
>> In fact, when I push the ptt I don't need the RX-ant part to be active,
>> as I'm transmitting, and -at least in my setup- I have no other
>> rigs/devices that need that input (I mean, no in-band receivers and so
>> on).
>> Instead of using external relays (ptt-activated) that cut out the rx
>> input when I am transmitting, why the K3 firmware just doesn't disable
>> the RX ant input on its own (and re-enables it if needed when releasing
>> the ptt)?
>> Maybe I'm missing something here, or that could be a nice improvement
>> for a next firmware release.
>>
>> Thanks for any comment,
>> Ciao 73
>> Fabio
>> IZ4AFW / IO4W / NZ1W
>>
>>
>> ---
>> Questa e-mail è stata controllata per individuare virus con Avast
>> antivirus.
>> https://www.avast.com/antivirus
>>
>> ______________________________________________________________
>> 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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Fabio IZ4AFW / NZ1W

Re: RX antenna & carrier-operated relay

In reply to this post by Jessie Oberreuter-2

Jessie,
thanks for the input.
On RTTY and other constant-envelope modes you can hear the RX antenna
relay switching at the start of the tx and again when the tx ends. But
on SSB it's really annoying as it continuously clicks (well, at least it
protects the radio! HI). Just wondering why the RX antennas are not
disconnected by the firmware while transmitting.

Ciao,
Fabio
IZ4AFW / IO4W / NZ1W

Il 04.03.2017 20:12, Jessie Oberreuter ha scritto:

>
> The 2nd Rx port is on a relay, and not a particularly fast or quiet
> one in my K3. I'd hate to operate QSK that way! I could see a menu
> option that would activate it with a longer hang time, but you'd
> probably be better off with an external switch and/or front-end
> protector. -kb7psg
>
>
> On Sat, 4 Mar 2017, Fabio IZ4AFW / NZ1W wrote:
>
>> Hi guys,
>> I was thinking of a possible firmware improvement related to the
>> carrier operated relay.
>> I use my radio on a small lot and recently I added a short beverage
>> antenna for low-bands receiving. My main activity is single-op
>> contesting.
>> Because of the interaction between the tx antennas and the beverage, on
>> some bands I have the COR (carrier operated relay) activating when I use
>> high power.
>> I know the good solutions, but my point is different.
>> As I have the COR activating only when the RX Ant input is selected, why
>> doesn't the K3 firmware disable it when pushing the ptt?
>>
>> In fact, when I push the ptt I don't need the RX-ant part to be active,
>> as I'm transmitting, and -at least in my setup- I have no other
>> rigs/devices that need that input (I mean, no in-band receivers and so
>> on).
>> Instead of using external relays (ptt-activated) that cut out the rx
>> input when I am transmitting, why the K3 firmware just doesn't disable
>> the RX ant input on its own (and re-enables it if needed when releasing
>> the ptt)?
>> Maybe I'm missing something here, or that could be a nice improvement
>> for a next firmware release.
>>
>> Thanks for any comment,
>> Ciao 73
>> Fabio
>> IZ4AFW / IO4W / NZ1W
>>
>>
>> ---
>> Questa e-mail è stata controllata per individuare virus con Avast
>> antivirus.
>> https://www.avast.com/antivirus
>>
>> ______________________________________________________________
>> 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]
>>

Jim Brown-10

Re: RX antenna & carrier-operated relay

In reply to this post by Fabio IZ4AFW / NZ1W

Fabio,

You've seen my antenna farm -- Beverages run within 20-30 ft of my 160M
TX antenna facing NE. Beverages feed a DX Eng preamp before going the
sub-RX. I don't do anything special to protect the radio, but it does
occasionally protect itself. I also use the Beverages on 80, 40, and
30M, but TX antennas are much farther away (more than 100 ft). This is
at 1.5 kW with a Ten Tec tube amp.

BTW -- I just added a pair of VE3DO loops tuned for 160M and aimed to
EU. Each loop is a rectangle 40 ft long and 10 ft vertical, with the
bottom wire 2 ft off the ground and fed at the center. Details on
OK1RR's website. The two loops are spaced 5/8 wavelength (350 ft). You
probably don't have room for two loops, but you might fit one of them.

73, Jim K9YC

On Sat,3/4/2017 2:11 PM, Fabio IZ4AFW / NZ1W wrote:

> Hi Dave,
> thanks for the suggestion.
> I tried doing a quick measure using a cross-needle SWR meter today,
> using the lowest setting.
> On 40m the power appears to just deflect the needle, well below the 0.5W
> mark. Probably I could say less than 250mW, maybe 100mW.
> I usually have an external relay in a box to disconnect the RX antennas
> while transmitting, but not today.
> I was thinking why the RX antennas remain connected when transmitting if
> there's not another use in a typical single-op station.
>
> Thanks,
> Ciao
> Fabio
> IZ4AFW / IO4W / NZ1W
>
>
> Il 04.03.2017 13:12, David Olean ha scritto:
>> Hello Fabio
>>
>> I have two beverages that are somewhat close to my TX antenna. One
>> had about 75 mw on it during TX while beverage #2 had about 1 watt! This
>> is enough power to cause damage to preamps, so I made two power limiters
>> and now the inputs are clipped at about 0 dBm. All it took was two
>> transformers and two diodes in a box. Do you know what the power level
>> is on your beverage during transmit periods? Really high power levels
>> could burn up the transformers. Disconnecting the antenna is a good
>> idea too.
>>
>> Dave K1WHS
>>
>>
>> On 3/4/2017 9:53 AM, Fabio IZ4AFW / NZ1W wrote:
>>> Hi guys,
>>> I was thinking of a possible firmware improvement related to the
>>> carrier operated relay.
>>> I use my radio on a small lot and recently I added a short beverage
>>> antenna for low-bands receiving. My main activity is single-op
>>> contesting.
>>> Because of the interaction between the tx antennas and the beverage, on
>>> some bands I have the COR (carrier operated relay) activating when I use
>>> high power.
>>> I know the good solutions, but my point is different.
>>> As I have the COR activating only when the RX Ant input is selected, why
>>> doesn't the K3 firmware disable it when pushing the ptt?
>>>
>>> In fact, when I push the ptt I don't need the RX-ant part to be active,
>>> as I'm transmitting, and -at least in my setup- I have no other
>>> rigs/devices that need that input (I mean, no in-band receivers and so
>>> on).
>>> Instead of using external relays (ptt-activated) that cut out the rx
>>> input when I am transmitting, why the K3 firmware just doesn't disable
>>> the RX ant input on its own (and re-enables it if needed when releasing
>>> the ptt)?
>>> Maybe I'm missing something here, or that could be a nice improvement
>>> for a next firmware release.
>>>
>>> Thanks for any comment,
>>> Ciao 73
>>> Fabio
>>> IZ4AFW / IO4W / NZ1W

Don23805

Re: RX antenna & carrier-operated relay

Didn't I see something about "protectors" built into the K3S antenna
connectors? Are they like the transient discharge tubes that protect
(somewhat) against lightning? Is there also one on the RX antenna input?

Don K2BIO

On 03/04/2017 06:05 PM, Jim Brown wrote:

> Fabio,
>
> You've seen my antenna farm -- Beverages run within 20-30 ft of my
> 160M TX antenna facing NE. Beverages feed a DX Eng preamp before going
> the sub-RX. I don't do anything special to protect the radio, but it
> does occasionally protect itself. I also use the Beverages on 80, 40,
> and 30M, but TX antennas are much farther away (more than 100 ft).
> This is at 1.5 kW with a Ten Tec tube amp.
>
> BTW -- I just added a pair of VE3DO loops tuned for 160M and aimed to
> EU. Each loop is a rectangle 40 ft long and 10 ft vertical, with the
> bottom wire 2 ft off the ground and fed at the center. Details on
> OK1RR's website. The two loops are spaced 5/8 wavelength (350 ft). You
> probably don't have room for two loops, but you might fit one of them.
>
> 73, Jim K9YC
>
> On Sat,3/4/2017 2:11 PM, Fabio IZ4AFW / NZ1W wrote:
>> Hi Dave,
>> thanks for the suggestion.
>> I tried doing a quick measure using a cross-needle SWR meter today,
>> using the lowest setting.
>> On 40m the power appears to just deflect the needle, well below the 0.5W
>> mark. Probably I could say less than 250mW, maybe 100mW.
>> I usually have an external relay in a box to disconnect the RX antennas
>> while transmitting, but not today.
>> I was thinking why the RX antennas remain connected when transmitting if
>> there's not another use in a typical single-op station.
>>
>> Thanks,
>> Ciao
>> Fabio
>> IZ4AFW / IO4W / NZ1W
>>
>>
>> Il 04.03.2017 13:12, David Olean ha scritto:
>>> Hello Fabio
>>>
>>> I have two beverages that are somewhat close to my TX antenna.
>>> One
>>> had about 75 mw on it during TX while beverage #2 had about 1 watt!
>>> This
>>> is enough power to cause damage to preamps, so I made two power
>>> limiters
>>> and now the inputs are clipped at about 0 dBm. All it took was two
>>> transformers and two diodes in a box. Do you know what the power level
>>> is on your beverage during transmit periods? Really high power levels
>>> could burn up the transformers. Disconnecting the antenna is a good
>>> idea too.
>>>
>>> Dave K1WHS
>>>
>>>
>>> On 3/4/2017 9:53 AM, Fabio IZ4AFW / NZ1W wrote:
>>>> Hi guys,
>>>> I was thinking of a possible firmware improvement related to the
>>>> carrier operated relay.
>>>> I use my radio on a small lot and recently I added a short beverage
>>>> antenna for low-bands receiving. My main activity is single-op
>>>> contesting.
>>>> Because of the interaction between the tx antennas and the
>>>> beverage, on
>>>> some bands I have the COR (carrier operated relay) activating when
>>>> I use
>>>> high power.
>>>> I know the good solutions, but my point is different.
>>>> As I have the COR activating only when the RX Ant input is
>>>> selected, why
>>>> doesn't the K3 firmware disable it when pushing the ptt?
>>>>
>>>> In fact, when I push the ptt I don't need the RX-ant part to be
>>>> active,
>>>> as I'm transmitting, and -at least in my setup- I have no other
>>>> rigs/devices that need that input (I mean, no in-band receivers and so
>>>> on).
>>>> Instead of using external relays (ptt-activated) that cut out the rx
>>>> input when I am transmitting, why the K3 firmware just doesn't disable
>>>> the RX ant input on its own (and re-enables it if needed when
>>>> releasing
>>>> the ptt)?
>>>> Maybe I'm missing something here, or that could be a nice improvement
>>>> for a next firmware release.
>>>>
>>>> Thanks for any comment,
>>>> Ciao 73
>>>> Fabio
>>>> IZ4AFW / IO4W / NZ1W
>
> ______________________________________________________________
> 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]

Fabio IZ4AFW / NZ1W

Re: RX antenna & carrier-operated relay

In reply to this post by Jim Brown-10

Jim,
thanks for the info about the VE3DO loop, I'll check OK1RR webpage out.
My short beverage runs away from the tower, starting about 5 meters from
it and going towards USA (NW). Unfortunately I don't have much more
space to relocate the beverage farther away.
My idea was to ask adding a menu option that automatically switches off
the RX-ant input when the operator pushes the ptt, as usually the
single-op doesn't need to keep it connected while transmitting. Of
course it should also re-enable it at the end of the tx if needed.
I know that an external relay is easy to use, but this could come for
free when a new firmware is released.

Ciao,
Fabio
IZ4AFW / IO4W / NZ1W

Il 05.03.2017 00:05, Jim Brown ha scritto: