Elecraft

RX antenna protection

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W1PEF-2

RX antenna protection

I am considering a Rx antenna but my property is small and concerned about strong signals over powering the receiver. Does the K3S have built-in protection?
Does anyone use a loop receive antenna or BOG antenna ... would like some recommendations from actual users of receive antennas.
Have the complete K-Line and would like to improve my ability to hear.
Thanks for any advice...
Paul
W1PEF

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Drew AF2Z

Re: RX antenna protection

Same situation here: small space and would like to try some low noise
receive antennas. I recently bought an Array Solutions AS-RXFEP rf
limiter to use on the RX Ant port of my K3. Haven't tried it yet but
looks like it will do the job.

73,
Drew
AF2Z

On 08/14/17 21:48, W1PEF wrote:
> I am considering a Rx antenna but my property is small and concerned about strong signals over powering the receiver. Does the K3S have built-in protection?
> Does anyone use a loop receive antenna or BOG antenna ... would like some recommendations from actual users of receive antennas.
> Have the complete K-Line and would like to improve my ability to hear.
> Thanks for any advice...
> Paul
> W1PEF
>
>
>

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Chuck Milam, N9KY

Re: RX antenna protection

Also, check out the DX Engineering Receiver Guard Electronic RF Limiters:

<goog_228257669>
https://www.dxengineering.com/search/part-type/hf-receive-antenna-system-devices/product-line/dx-engineering-receiver-guard-electronic-rf-limiters?autoview=SKU&sortby=Default&sortorder=Ascending

---
Chuck Milam, N9KY
[hidden email]

On Mon, Aug 14, 2017 at 11:07 PM, Drew AF2Z <[hidden email]> wrote:

> Same situation here: small space and would like to try some low noise
> receive antennas. I recently bought an Array Solutions AS-RXFEP rf limiter
> to use on the RX Ant port of my K3. Haven't tried it yet but looks like it
> will do the job.
>
>
> 73,
> Drew
> AF2Z
>
>
>
>
> On 08/14/17 21:48, W1PEF wrote:
>
>> I am considering a Rx antenna but my property is small and concerned
>> about strong signals over powering the receiver. Does the K3S have built-in
>> protection?
>> Does anyone use a loop receive antenna or BOG antenna ... would like some
>> recommendations from actual users of receive antennas.
>> Have the complete K-Line and would like to improve my ability to hear.
>> Thanks for any advice...
>> Paul
>> W1PEF
>>
>>
>>
>>
> ______________________________________________________________
> 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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>

markmusick

Re: RX antenna protection

Paul,
I use several different receive antennas and use all the ones I am going to
suggest.
For your small lot, you didn't say how small, I would look at the Pixel
loop, K9AY and RBOG.
I have used these and they work. You can get all three from DX Engineering.
From ARRAY Solutions there is the Shared Apex Loop. It will take up about
the same space as a K9AY. I have not used one of these so can't say
personally how well it works, but people I know that have used them speak
highly of this antenna.
You have gotten two good suggestions for front end protection. I use the DX
Engineering receiver guard model RG-5000. You don't need the RG-5000HD
unless you're in a contest environment.
Keep us posted on your progress.

73,
Mark, WB9CIF

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Chuck Milam, N9KY
Sent: Tuesday, August 15, 2017 1:16 PM
To: Elecraft Mail List <[hidden email]>
Subject: Re: [Elecraft] RX antenna protection

Also, check out the DX Engineering Receiver Guard Electronic RF Limiters:

<goog_228257669>
https://www.dxengineering.com/search/part-type/hf-receive-antenna-system-dev
ices/product-line/dx-engineering-receiver-guard-electronic-rf-limiters?autov
iew=SKU&sortby=Default&sortorder=Ascending

---
Chuck Milam, N9KY
[hidden email]

On Mon, Aug 14, 2017 at 11:07 PM, Drew AF2Z <[hidden email]> wrote:

> Same situation here: small space and would like to try some low noise
> receive antennas. I recently bought an Array Solutions AS-RXFEP rf
> limiter to use on the RX Ant port of my K3. Haven't tried it yet but
> looks like it will do the job.
>
>
> 73,
> Drew
> AF2Z
>
>
>
>
> On 08/14/17 21:48, W1PEF wrote:
>
>> I am considering a Rx antenna but my property is small and concerned
>> about strong signals over powering the receiver. Does the K3S have
>> built-in protection?
>> Does anyone use a loop receive antenna or BOG antenna ... would like
>> some recommendations from actual users of receive antennas.
>> Have the complete K-Line and would like to improve my ability to hear.
>> Thanks for any advice...
>> Paul
>> W1PEF
>>
>>
>>
>>
> ______________________________________________________________
> 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]
>

john@kk9a.com

Re: RX antenna protection

In reply to this post by W1PEF-2

Great question! I asked the same thing once and never got an answer so to
be safe I either short the RX antenna during transmit or if SO2R I use DXE
receiver guards. It would be nice if the K3S had a similar built in
protector.

John KK9A

W1PEF wrote
Mon Aug 14 21:48:29 EDT 2017

I am considering a Rx antenna but my property is small and concerned about
strong signals over powering the receiver. Does the K3S have built-in
protection?
Does anyone use a loop receive antenna or BOG antenna ... would like some
recommendations from actual users of receive antennas.
Have the complete K-Line and would like to improve my ability to hear.
Thanks for any advice...
Paul
W1PEF

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Don Wilhelm

Re: RX antenna protection

John,

The K3S does have protection on the RX ANT input. It is in the form of
a COR (carrier operated relay) that will close in the presence of a high
RF Field.
While that protects the K3S, the relay clacking can be bothersome, so if
you do hear that relay clacking, you may want to consider some form of
external protection.

73,
Don W3FPR

On 8/15/2017 10:50 AM, [hidden email] wrote:
> Great question! I asked the same thing once and never got an answer so to
> be safe I either short the RX antenna during transmit or if SO2R I use DXE
> receiver guards. It would be nice if the K3S had a similar built in
> protector.
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Ignacy

Re: RX antenna protection

In reply to this post by john@kk9a.com

If a receive antenna has a preamp, there no need to do any antenna guard since the preamp cannot destroy K3.

I used K9AY, K7TJR 3 el array, and a Wellbrook loop close to transmit antennas. None was turned off during transmit. Both have preamps and nothing was damaged despite running a KW. Of all 3, K7TJR was the best by far.

BTW, the RX ANT input in K3 is protected by a RF activated relay.

Ignacy, NO9E

Bob McGraw - K4TAX

Re: RX antenna protection

In reply to this post by john@kk9a.com

See page 63 of the manual. Also page 70 under Receive. "*HI RFI*
warning:"

RFI DET - *NOR *enables detection of high RFI at the antenna in receive
mode. (see HI RFI warning. *Troubleshooting*). Set to OFF to disable
the warning.

73
Bob, K4TAX
K3S s/n 10163

On 8/15/2017 9:50 AM, [hidden email] wrote:

> Great question! I asked the same thing once and never got an answer so to
> be safe I either short the RX antenna during transmit or if SO2R I use DXE
> receiver guards. It would be nice if the K3S had a similar built in
> protector.
>
> John KK9A
>
> W1PEF wrote
> Mon Aug 14 21:48:29 EDT 2017
>
> I am considering a Rx antenna but my property is small and concerned about
> strong signals over powering the receiver. Does the K3S have built-in
> protection?
> Does anyone use a loop receive antenna or BOG antenna ... would like some
> recommendations from actual users of receive antennas.
> Have the complete K-Line and would like to improve my ability to hear.
> Thanks for any advice...
> Paul
> W1PEF
>
>
> ______________________________________________________________
> 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]
>

Richard Fjeld-2

Re: RX antenna protection

I haven’t been following this, and just noticed it, so I hope I am in sync with this.

Just a note to say that years ago, I had a B&W Electronic Antenna Switch (I think it was called) that had one or two tubes in it.
It worked perfectly to bias the receive completely and immediately as soon as transmit was detected. It allowed full break-in for CW work. I would like to see something like this again today in solid state. I think this would be the ticket for what you need. I haven’t looked, so I don’t know if anyone is marketing such a device.

Rich, n0ce

From: Bob McGraw K4TAX<mailto:[hidden email]>
Sent: Tuesday, August 15, 2017 11:00 AM
To: [hidden email]<mailto:[hidden email]>
Subject: Re: [Elecraft] RX antenna protection

See page 63 of the manual. Also page 70 under Receive. "*HI RFI*
warning:"

RFI DET - *NOR *enables detection of high RFI at the antenna in receive
mode. (see HI RFI warning. *Troubleshooting*). Set to OFF to disable
the warning.

73
Bob, K4TAX
K3S s/n 10163

On 8/15/2017 9:50 AM, [hidden email] wrote:

Richard Fjeld-2

Re: RX antenna protection

I just read Ignacy’s post telling that the K3 receive ant input has a RF activated relay. I’m glad to see that.

Rich, n0ce

From: Richard Fjeld<mailto:[hidden email]>
Sent: Tuesday, August 15, 2017 12:00 PM
To: Bob McGraw K4TAX<mailto:[hidden email]>; [hidden email]<mailto:[hidden email]>
Subject: Re: [Elecraft] RX antenna protection

I haven’t been following this, and just noticed it, so I hope I am in sync with this.

Just a note to say that years ago, I had a B&W Electronic Antenna Switch (I think it was called) that had one or two tubes in it.
It worked perfectly to bias the receive completely and immediately as soon as transmit was detected. It allowed full break-in for CW work. I would like to see something like this again today in solid state. I think this would be the ticket for what you need. I haven’t looked, so I don’t know if anyone is marketing such a device.

Rich, n0ce

From: Bob McGraw K4TAX<mailto:[hidden email]>
Sent: Tuesday, August 15, 2017 11:00 AM
To: [hidden email]<mailto:[hidden email]>
Subject: Re: [Elecraft] RX antenna protection

See page 63 of the manual. Also page 70 under Receive. "*HI RFI*
warning:"

RFI DET - *NOR *enables detection of high RFI at the antenna in receive
mode. (see HI RFI warning. *Troubleshooting*). Set to OFF to disable
the warning.

73
Bob, K4TAX
K3S s/n 10163

On 8/15/2017 9:50 AM, [hidden email] wrote:

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John K9UWA-2

Re: RX antenna protection

In reply to this post by Richard Fjeld-2

We have been operating this way with full break-in for many years using the
KD9SV products. First it was just the "Front End Saver" which removes and
grounds the incoming rcv antenna from your radio during transmit. As a "Fail
Safe" the device also prevents the Amplifier from working by removing the
PTT line to the amp if by any chance the relays in the KD9SV device fail to
operate. Later it is now incorporated into the various RBOG and other
Pre-Amp devices that KD9SV sells... through DX-Engineering.

Disclaimer Statement: Yes I am a friend of Gary's. Call me a more than
happy customer. I complained many years ago after I fried the front end of
my IC-765 radios a couple times and Gary started building these devices.
They Work and I am happy. No more blown front ends no more blown
pre-amps.

John k9uwa

> Just a note to say that years ago, I had a B&W Electronic Antenna Switch (I
> think it was called) that had one or two tubes in it. It worked perfectly to
> bias the receive completely and immediately as soon as transmit was detected.
> It allowed full break-in for CW work. I would like to see something like this
> again today in solid state. I think this would be the ticket for what you need.
> I havenTMt looked, so I donTMt know if anyone is marketing such a device.
>
> Rich, n0ce

John Goller, K9UWA & Jean Goller, N9PXF
Antique Radio Restorations
[hidden email]
Visit our Web Site at:
http://www.JohnJeanAntiqueRadio.com
4836 Ranch Road
Leo, IN 46765
USA
1-260-637-6426

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a45wg-3

Re: RX antenna protection

John,
Very sound advice.

I am using a Alpha Delta T33g50 that I picked up at HRO Denver, Co; The Red Pittaya antenna (Cobwebb) is 15 feet below the TH-7 which is emitting aprox 500W.

It has survived for 12 months so far, which has amazed me.

Regards

Tim, A45WG

> On Aug 15, 2017, at 10:06 PM, John K9UWA <[hidden email]> wrote:
>
> We have been operating this way with full break-in for many years using the
> KD9SV products. First it was just the "Front End Saver" which removes and
> grounds the incoming rcv antenna from your radio during transmit. As a "Fail
> Safe" the device also prevents the Amplifier from working by removing the
> PTT line to the amp if by any chance the relays in the KD9SV device fail to
> operate. Later it is now incorporated into the various RBOG and other
> Pre-Amp devices that KD9SV sells... through DX-Engineering.
>
> Disclaimer Statement: Yes I am a friend of Gary's. Call me a more than
> happy customer. I complained many years ago after I fried the front end of
> my IC-765 radios a couple times and Gary started building these devices.
> They Work and I am happy. No more blown front ends no more blown
> pre-amps.
>
> John k9uwa
>
>> Just a note to say that years ago, I had a B&W Electronic Antenna Switch (I
>> think it was called) that had one or two tubes in it. It worked perfectly to
>> bias the receive completely and immediately as soon as transmit was detected.
>> It allowed full break-in for CW work. I would like to see something like this
>> again today in solid state. I think this would be the ticket for what you need.
>> I havenTMt looked, so I donTMt know if anyone is marketing such a device.
>>
>> Rich, n0ce
>
> John Goller, K9UWA & Jean Goller, N9PXF
> Antique Radio Restorations
> [hidden email]
> Visit our Web Site at:
> http://www.JohnJeanAntiqueRadio.com
> 4836 Ranch Road
> Leo, IN 46765
> USA
> 1-260-637-6426
>
> ______________________________________________________________
> 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]

Vic Rosenthal

Re: RX antenna protection

In reply to this post by markmusick

I'm using a Pixel Loop. Advantages are that it is small, can be rotated to null a noise source, and works on all HF bands. It is vertically polarized, so if you have a horizontal antenna you can get a useful diversity effect without too much physical separation. It has a built in relay that disconnects it to protect your receiver while transmitting. I use diversity almost all the time, and it definitely improves copy of CW signals.

Vic 4X6GP

> On 15 Aug 2017, at 17:01, Mark E. Musick <[hidden email]> wrote:
>
> Paul,
> I use several different receive antennas and use all the ones I am going to
> suggest.
> For your small lot, you didn't say how small, I would look at the Pixel
> loop, K9AY and RBOG.
> I have used these and they work. You can get all three from DX Engineering.
> From ARRAY Solutions there is the Shared Apex Loop. It will take up about
> the same space as a K9AY. I have not used one of these so can't say
> personally how well it works, but people I know that have used them speak
> highly of this antenna.
> You have gotten two good suggestions for front end protection. I use the DX
> Engineering receiver guard model RG-5000. You don't need the RG-5000HD
> unless you're in a contest environment.
> Keep us posted on your progress.
>
> 73,
> Mark, WB9CIF
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Chuck Milam, N9KY
> Sent: Tuesday, August 15, 2017 1:16 PM
> To: Elecraft Mail List <[hidden email]>
> Subject: Re: [Elecraft] RX antenna protection
>
> Also, check out the DX Engineering Receiver Guard Electronic RF Limiters:
>
> <goog_228257669>
> https://www.dxengineering.com/search/part-type/hf-receive-antenna-system-dev
> ices/product-line/dx-engineering-receiver-guard-electronic-rf-limiters?autov
> iew=SKU&sortby=Default&sortorder=Ascending
>
> ---
> Chuck Milam, N9KY
> [hidden email]
>
>> On Mon, Aug 14, 2017 at 11:07 PM, Drew AF2Z <[hidden email]> wrote:
>>
>> Same situation here: small space and would like to try some low noise
>> receive antennas. I recently bought an Array Solutions AS-RXFEP rf
>> limiter to use on the RX Ant port of my K3. Haven't tried it yet but
>> looks like it will do the job.
>>
>>
>> 73,
>> Drew
>> AF2Z
>>
>>
>>
>>
>>> On 08/14/17 21:48, W1PEF wrote:
>>>
>>> I am considering a Rx antenna but my property is small and concerned
>>> about strong signals over powering the receiver. Does the K3S have
>>> built-in protection?
>>> Does anyone use a loop receive antenna or BOG antenna ... would like
>>> some recommendations from actual users of receive antennas.
>>> Have the complete K-Line and would like to improve my ability to hear.
>>> Thanks for any advice...
>>> Paul
>>> W1PEF

Vic Rosenthal

Re: RX antenna protection

In reply to this post by Ignacy

I disagree. A good preamp like the DXE preamps can handle large signals and still be linear. That means they can output a lot of power. Do not assume you are safe if there is a preamp unless it is a lousy one!

Vic 4X6GP

> On 15 Aug 2017, at 18:07, Ignacy <[hidden email]> wrote:
>
> If a receive antenna has a preamp, there no need to do any antenna guard
> since the preamp cannot destroy K3.
>
> I used K9AY, K7TJR 3 el array, and a Wellbrook loop close to transmit
> antennas. None was turned off during transmit. Both have preamps and
> nothing was damaged despite running a KW. Of all 3, K7TJR was the best by
> far.
>
> BTW, the RX ANT input in K3 is protected by a RF activated relay.
>
> Ignacy, NO9E

KENT TRIMBLE

Re: RX antenna protection

In reply to this post by Richard Fjeld-2

The Johnson 250-39 and B&W 380 T/R switches both had a certain amount of
"suck-out" but they did protect tube receivers.

I had both (still do) and preferred the Johnson.

http://wireless-girl.com/Projects/TRswitches/Johnson/

Note the warning about use with solid-state equipment, however.

73,

Kent K9ZTV

On 8/15/2017 11:58 AM, someone wrote:
> Just a note to say that years ago, I had a B&W Electronic Antenna Switch (I think it was called) that had one or two tubes in it.
> It worked perfectly to bias the receive completely and immediately as soon as transmit was detected. It allowed full break-in for CW work. I would like to see something like this again today in solid state. I think this would be the ticket for what you need. I haven’t looked, so I don’t know if anyone is marketing such a device.
>
>

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Dave Sublette

Re: RX antenna protection

I had one once. It was a tremendous TVI generator….

K4TO

> On Aug 15, 2017, at 4:07 PM, KENT TRIMBLE <[hidden email]> wrote:
>
> The Johnson 250-39 and B&W 380 T/R switches both had a certain amount of "suck-out" but they did protect tube receivers.
>
> I had both (still do) and preferred the Johnson.
>
> http://wireless-girl.com/Projects/TRswitches/Johnson/
>
> Note the warning about use with solid-state equipment, however.
>
> 73,
>
> Kent K9ZTV
>
>
>
> On 8/15/2017 11:58 AM, someone wrote:
>> Just a note to say that years ago, I had a B&W Electronic Antenna Switch (I think it was called) that had one or two tubes in it.
>> It worked perfectly to bias the receive completely and immediately as soon as transmit was detected. It allowed full break-in for CW work. I would like to see something like this again today in solid state. I think this would be the ticket for what you need. I haven’t looked, so I don’t know if anyone is marketing such a device.
>>
>>
>
> ______________________________________________________________
> 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
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> Message delivered to [hidden email]

Ignacy

Re: RX antenna protection

In reply to this post by Vic Rosenthal

This is my experience. Making a large-signal preamp is usually a waste of
power since it is a mixer that is a limiting factor.
I can believe that a device from DX Engineering can be poorly designed.
Have NCC-2. Weighs like a tank but fragile like a baby.
Ignacy, NO9E

On Tue, Aug 15, 2017 at 3:59 PM, Vic Rosenthal <[hidden email]> wrote:

> I disagree. A good preamp like the DXE preamps can handle large signals
> and still be linear. That means they can output a lot of power. Do not
> assume you are safe if there is a preamp unless it is a lousy one!
>
> Vic 4X6GP
>
> > On 15 Aug 2017, at 18:07, Ignacy <[hidden email]> wrote:
> >
> > If a receive antenna has a preamp, there no need to do any antenna guard
> > since the preamp cannot destroy K3.
> >
> > I used K9AY, K7TJR 3 el array, and a Wellbrook loop close to transmit
> > antennas. None was turned off during transmit. Both have preamps and
> > nothing was damaged despite running a KW. Of all 3, K7TJR was the best
> by
> > far.
> >
> > BTW, the RX ANT input in K3 is protected by a RF activated relay.
> >
> > Ignacy, NO9E
>