K3 Sub Receiver and protecting the Sub RX input
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K3 Sub Receiver and protecting the Sub RX input
 
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I ordered the sub receiver and in the conversation with Elecraft I was informed that it is good idea to build a device that would short the dedicated RX antenna to ground to protect it during transmit.
The simple way would be a relay but I'd rather not hear a relay click with each transmission. I was wondering what others are using to accomplish this. Thank you ______________________________________________________________ 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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There are a couple of things to think about. How much power are you running? How close is the receive antenna to your transmitting antenna? Does your receive only antenna possibly have an interface that can connect to the key out of the K3? (My Pixel Loop antenna has such a device)
You can also try it out and listen for a clicking noise from the carrier operated relay inside the K3. It is a protective relay that will energize if it sees too much power coming in on the RX antenna input. If you hear it clicking then it is a good idea to consider additional protection. There are external protective devices available that you can purchase. DX Engineering and Array Solutions have them I think there are others out there. http://www.dxengineering.com/search/department/antennas/section/receive-antennas-and-arrays/product-line/dx-engineering-receiver-guard-5000-electronic-rf-limiters?autoview=SKU&N=4294953330%2B4294951218&sortby=Default&sortorder=Ascending http://www.arraysolutions.com/Products/as_rxfep.htm 73, Mike K2MK
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Re: K3 Sub Receiver and protecting the Sub RX input
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In reply to this post by Elecraft mailing list
An alternative to a relay (which should ground the sub-receiver ant)
is using a pin diode to short the input. Typically one uses a coupling capacitor to isolate the antenna from the circuit which will have a low value of dc bias to turn on the pin diode which will conduct to ground and short the antenna ckt. I assume the K3 sub-receiver antenna ckt is capacitively coupled to isolate it dc wise. Use a RF choke between pin diode and antenna to keep from loading the antenna in normal use. hint: google pin diode antenna switching. Use KEY OUT ckt from the K3 to control the pin diode via a transistor switch that applies the bias thru a dropping resistor. You will have to do some design work - not plug-n-play freebie Many ham rigs that do QSK use pin-diode TR switching. 73, Ed - KL7UW http://www.kl7uw.com "Kits made by KL7UW" Dubus Mag business: [hidden email] ______________________________________________________________ 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] |
Re: K3 Sub Receiver and protecting the Sub RX input
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Administrator
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In reply to this post by Elecraft mailing list
This would only be necessary if you're running high power and/or the antenna to be used with the KRX3 is close to the transmit antenna. Could you describe your antenna system?
Wayne N6KR ---- http://www.elecraft.com > On Jan 27, 2015, at 7:12 AM, Harry Yingst via Elecraft <[hidden email]> wrote: > > I ordered the sub receiver and in the conversation with Elecraft I was informed that it is good idea to build a device that would short the dedicated RX antenna to ground to protect it during transmit. > The simple way would be a relay but I'd rather not hear a relay click with each transmission. > I was wondering what others are using to accomplish this. > > Thank you > ______________________________________________________________ > 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] 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] |
Re: K3 Sub Receiver and protecting the Sub RX input
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Perhaps you could clarify protection on RX inputs. I have the KRX3 and
run the internal 100 watt amp. Sometimes I share the same antenna with TX, ANT 1 or ANT2. I assumed there that the RX is protected. Sometimes I use the AUX antenna for diversity receive. Is that input not protected? When does it need to be? Is there a general rule? TNX and love the rig: K3, P3, KXR3 and 100 watt internal amp. Phil, W0XI, KS > Wayne Burdick <mailto:[hidden email]> > Tuesday, January 27, 2015 1:07 PM > This would only be necessary if you're running high power and/or the > antenna to be used with the KRX3 is close to the transmit antenna. > Could you describe your antenna system? > > Wayne > N6KR > > ---- > http://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 > Message delivered to [hidden email] > > Harry Yingst via Elecraft <mailto:[hidden email]> > Tuesday, January 27, 2015 9:12 AM > I ordered the sub receiver and in the conversation with Elecraft I was > informed that it is good idea to build a device that would short the > dedicated RX antenna to ground to protect it during transmit. > The simple way would be a relay but I'd rather not hear a relay click > with each transmission. > I was wondering what others are using to accomplish this. > > Thank you > ______________________________________________________________ > 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] --- This email has been checked for viruses by Avast antivirus software. http://www.avast.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 Message delivered to [hidden email] |
Re: K3 Sub Receiver and protecting the Sub RX input
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Phil,
The K3 ANT1 and ANT2 connections are not of concern, they are protected by the T/R circuits in the K3. The AUX ant is protected by a COR (Carrier Operated Relay) that will activate if there is too much RF being brought in by the AUX antenna. While it should protect the K3 (and KRX3) from damage, you will hear the COR clicking as you transmit. If you do hear such relay clicking, the "cure" is to move the RX antenna further out of the field of the TX antenna, or provide some form of external 'protection' such as shorting the RX antenna input during TX or alternate means of disconnecting the RX antenna during RX. 73, Don W3FPR On 1/27/2015 4:41 PM, Phil Anderson wrote: > Perhaps you could clarify protection on RX inputs. I have the KRX3 and > run the internal 100 watt amp. > Sometimes I share the same antenna with TX, ANT 1 or ANT2. I assumed > there that the RX is protected. > Sometimes I use the AUX antenna for diversity receive. Is that input > not protected? When does it need to be? > ______________________________________________________________ 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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In reply to this post by wayne burdick
Wayne, can you please elaborate on what is sufficient antenna separation when a transmitter is operating on another antenna? I ask this because my K3 returning from a trip to Elecraft after damaging the front end. I assume it happened when I was testing an old boat anchor (Viking II, 100 watts) on an antenna 15’ feet away and parallel to the K3’s antenna. How far is enough? Yes, I realize that’s probably too close but at this point I am concerned.
I know the K3 is popular in Field Day and DXpedition operation so obviously it can work, but I’d like some guidelines. Thanks, Ken WA8JXM > On Jan 27, 2015, at 2:07 PM, Wayne Burdick <[hidden email]> wrote: > > This would only be necessary if you're running high power and/or the antenna to be used with the KRX3 is close to the transmit antenna. Could you describe your antenna system? > > Wayne > N6KR ______________________________________________________________ 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] |
Re: K3 Sub Receiver and protecting the Sub RX input
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In reply to this post by Elecraft mailing list
Yes....please Wayne.
Sent from my Verizon Wireless 4G LTE smartphone <div>-------- Original message --------</div><div>From: Ken <[hidden email]> </div><div>Date:01/27/2015 5:53 PM (GMT-05:00) </div><div>To: Wayne Burdick <[hidden email]> </div><div>Cc: Elecraft Reflector <[hidden email]> </div><div>Subject: Re: [Elecraft] K3 Sub Receiver and protecting the Sub RX input </div><div> </div>Wayne, can you please elaborate on what is sufficient antenna separation when a transmitter is operating on another antenna? I ask this because my K3 returning from a trip to Elecraft after damaging the front end. I assume it happened when I was testing an old boat anchor (Viking II, 100 watts) on an antenna 15’ feet away and parallel to the K3’s antenna. How far is enough? Yes, I realize that’s probably too close but at this point I am concerned. I know the K3 is popular in Field Day and DXpedition operation so obviously it can work, but I’d like some guidelines. Thanks, Ken WA8JXM > On Jan 27, 2015, at 2:07 PM, Wayne Burdick <[hidden email]> wrote: > > This would only be necessary if you're running high power and/or the antenna to be used with the KRX3 is close to the transmit antenna. Could you describe your antenna system? > > Wayne > N6KR ______________________________________________________________ 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] ______________________________________________________________ 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] |
Re: K3 Sub Receiver and protecting the Sub RX input
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In reply to this post by KEN-3
Ken,
I am not Wayne, but I can tell you that you question does not have a single answer. Do you run an amplifier? More power requires greater separation between the TX and the RX antennas. Another factor is the orientation of the antennas. An RX antenna in the null pattern of the TX antenna will not pick up a lot of TX RF, while an RX antenna broadside to the full TX antenna RF will be a problem. If the antennas have orthogonal polarity (one horizontal and one vertical), that will reduce the pickup on the RX antenna during TX. So a lot depends on the type of RX antenna, its orientation, its directivity, and a vast array of other factors. There is no one answer to your question, it all depends on your installation. 73, Don W3FPR On 1/27/2015 5:53 PM, Ken wrote: > Wayne, can you please elaborate on what is sufficient antenna separation when a transmitter is operating on another antenna? I ask this because my K3 returning from a trip to Elecraft after damaging the front end. I assume it happened when I was testing an old boat anchor (Viking II, 100 watts) on an antenna 15’ feet away and parallel to the K3’s antenna. How far is enough? Yes, I realize that’s probably too close but at this point I am concerned. > > I know the K3 is popular in Field Day and DXpedition operation so obviously it can work, but I’d like some guidelines. > > ______________________________________________________________ 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] |
Re: K3 Sub Receiver and protecting the Sub RX input
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In reply to this post by Harlan Sherriff
In general, ensure the coupled energy into the receiver antenna
connector is less than 1 watt under absolute worst case conditions, and preferably under 100 mW, and your receiver should be OK. Put another way, the antennas should be separated by 40 dB if running up to 1 kW, 30 dB if running up to 100W and 20 dB if running up to 10W. You might get away with 10 dB less coupling. If you can't get this level of isolation by physical separation and/or orientation of the antennas, provide some external means of reducing the signal to the receiver input. Yes, the K3 inputs are tested to higher levels than this, but why stress the radio and risk damage to or degradation of the receiver(s)? If you hear the receiver COR relay click when using the other transmitter, reduce the coupling between the antennas or otherwise prevent the excess energy from reaching the receiver input. 73, Lyle KK7P > ...can you please elaborate on what is sufficient antenna separation when a transmitter is operating on another antenna? ______________________________________________________________ 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] |
Re: K3 Sub Receiver and protecting the Sub RX input
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> In general, ensure the coupled energy into the receiver antenna > connector is less than 1 watt under absolute worst case conditions, > and preferably under 100 mW, and your receiver should be OK. > > Put another way, the antennas should be separated by 40 dB if running > up to 1 kW, 30 dB if running up to 100W and 20 dB if running up to > 10W. You might get away with 10 dB less coupling. Of course, I meant 10 dB *more* coupling, or 10 dB *less* isolation. > If you can't get this level of isolation by physical separation and/or > orientation of the antennas, provide some external means of reducing > the signal to the receiver input. > > Yes, the K3 inputs are tested to higher levels than this, but why > stress the radio and risk damage to or degradation of the receiver(s)? > > If you hear the receiver COR relay click when using the other > transmitter, reduce the coupling between the antennas or otherwise > prevent the excess energy from reaching the receiver input. > > 73, > > Lyle KK7P > >> ...can you please elaborate on what is sufficient antenna separation >> when a transmitter is operating on another antenna? > > ______________________________________________________________ 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] |
Re: K3 Sub Receiver and protecting the Sub RX input
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In reply to this post by Lyle Johnson
Thank you
From: Lyle Johnson <[hidden email]> To: Elecraft Reflector <[hidden email]> Sent: Tuesday, January 27, 2015 6:45 PM Subject: Re: [Elecraft] K3 Sub Receiver and protecting the Sub RX input In general, ensure the coupled energy into the receiver antenna connector is less than 1 watt under absolute worst case conditions, and preferably under 100 mW, and your receiver should be OK. Put another way, the antennas should be separated by 40 dB if running up to 1 kW, 30 dB if running up to 100W and 20 dB if running up to 10W. You might get away with 10 dB less coupling. If you can't get this level of isolation by physical separation and/or orientation of the antennas, provide some external means of reducing the signal to the receiver input. Yes, the K3 inputs are tested to higher levels than this, but why stress the radio and risk damage to or degradation of the receiver(s)? If you hear the receiver COR relay click when using the other transmitter, reduce the coupling between the antennas or otherwise prevent the excess energy from reaching the receiver input. 73, Lyle KK7P > ...can you please elaborate on what is sufficient antenna separation when a transmitter is operating on another antenna? ______________________________________________________________ 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] ______________________________________________________________ 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] |
Re: K3 Sub Receiver and protecting the Sub RX input
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In reply to this post by Mike K2MK
I've been using the Array Solutions device (AS-RXFEP) for over a year on
my K3. I have a homebrew magnetic loop connected to the K3 sub rx, with the loop located about 15 feet from the transmitting ground plane (about 6' above ground). Prior to installing the AS-RXFEP, the sub rx COR would be triggered with anything over about 25 watts. With the AS-RXFEP in place, I can run the KPA-500 at 600W without the COR ever tripping. The S-RXFEP has no relays, requires no supply voltage, and is simply installed in between the rx antenna and the sub rx antenna input via a pair of SO-239 connectors. 73, Dale WA8SRA > There are a couple of things to think about. How much power are you > running? > How close is the receive antenna to your transmitting antenna? Does your > receive only antenna possibly have an interface that can connect to the > key > out of the K3? (My Pixel Loop antenna has such a device) > > You can also try it out and listen for a clicking noise from the carrier > operated relay inside the K3. It is a protective relay that will energize > if > it sees too much power coming in on the RX antenna input. If you hear it > clicking then it is a good idea to consider additional protection. > > There are external protective devices available that you can purchase. DX > Engineering and Array Solutions have them I think there are others out > there. > > http://www.dxengineering.com/search/department/antennas/section/receive-antennas-and-arrays/product-line/dx-engineering-receiver-guard-5000-electronic-rf-limiters?autoview=SKU&N=4294953330%2B4294951218&sortby=Default&sortorder=Ascending > > http://www.arraysolutions.com/Products/as_rxfep.htm > > 73, > Mike K2MK > > > Elecraft mailing list wrote >> I ordered the sub receiver and in the conversation with Elecraft I was >> informed that it is good idea to build a device that would short the >> dedicated RX antenna to ground to protect it during transmit. >> The simple way would be a relay but I'd rather not hear a relay click >> with >> each transmission. >> I was wondering what others are using to accomplish this. >> >> Thank you > > ______________________________________________________________ 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] |
Re: K3 Sub Receiver and protecting the Sub RX input
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Thank you
Sounds like that may be my solution From: "[hidden email]" <[hidden email]> To: [hidden email] Sent: Tuesday, January 27, 2015 9:11 PM Subject: Re: [Elecraft] K3 Sub Receiver and protecting the Sub RX input I've been using the Array Solutions device (AS-RXFEP) for over a year on my K3. I have a homebrew magnetic loop connected to the K3 sub rx, with the loop located about 15 feet from the transmitting ground plane (about 6' above ground). Prior to installing the AS-RXFEP, the sub rx COR would be triggered with anything over about 25 watts. With the AS-RXFEP in place, I can run the KPA-500 at 600W without the COR ever tripping. The S-RXFEP has no relays, requires no supply voltage, and is simply installed in between the rx antenna and the sub rx antenna input via a pair of SO-239 connectors. 73, Dale WA8SRA > There are a couple of things to think about. How much power are you > running? > How close is the receive antenna to your transmitting antenna? Does your > receive only antenna possibly have an interface that can connect to the > key > out of the K3? (My Pixel Loop antenna has such a device) > > You can also try it out and listen for a clicking noise from the carrier > operated relay inside the K3. It is a protective relay that will energize > if > it sees too much power coming in on the RX antenna input. If you hear it > clicking then it is a good idea to consider additional protection. > > There are external protective devices available that you can purchase. DX > Engineering and Array Solutions have them I think there are others out > there. > > http://www.dxengineering.com/search/department/antennas/section/receive-antennas-and-arrays/product-line/dx-engineering-receiver-guard-5000-electronic-rf-limiters?autoview=SKU&N=4294953330%2B4294951218&sortby=Default&sortorder=Ascending > > http://www.arraysolutions.com/Products/as_rxfep.htm > > 73, > Mike K2MK > > > Elecraft mailing list wrote >> I ordered the sub receiver and in the conversation with Elecraft I was >> informed that it is good idea to build a device that would short the >> dedicated RX antenna to ground to protect it during transmit. >> The simple way would be a relay but I'd rather not hear a relay click >> with >> each transmission. >> I was wondering what others are using to accomplish this. >> >> Thank you > > ______________________________________________________________ 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] ______________________________________________________________ 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] |
Re: K3 Sub Receiver and protecting the Sub RX input
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In reply to this post by Lyle Johnson
Lyle and company,
To be clear are you talking about using another transmitter other than the K3's transmitter and external amplifier? This is my reading and I am just checking. Thank you. 73 Doug EI2CN -----Original Message----- From: Elecraft [mailto:[hidden email]] On Behalf Of Lyle Johnson Sent: 27 January 2015 23:45 To: Elecraft Reflector Subject: Re: [Elecraft] K3 Sub Receiver and protecting the Sub RX input In general, ensure the coupled energy into the receiver antenna connector is less than 1 watt under absolute worst case conditions, and preferably under 100 mW, and your receiver should be OK. Put another way, the antennas should be separated by 40 dB if running up to 1 kW, 30 dB if running up to 100W and 20 dB if running up to 10W. You might get away with 10 dB less coupling. If you can't get this level of isolation by physical separation and/or orientation of the antennas, provide some external means of reducing the signal to the receiver input. Yes, the K3 inputs are tested to higher levels than this, but why stress the radio and risk damage to or degradation of the receiver(s)? If you hear the receiver COR relay click when using the other transmitter, reduce the coupling between the antennas or otherwise prevent the excess energy from reaching the receiver input. 73, Lyle KK7P > ...can you please elaborate on what is sufficient antenna separation when a transmitter is operating on another antenna? ______________________________________________________________ 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] ______________________________________________________________ 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] |
Re: K3 Sub Receiver and protecting the Sub RX input
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Doug,
Not necessarily - the K3 RX antenna input can be exposed to RF from the TX antenna whether that is the K3 transmitting or another transmitter. In the case of another transmitter, one can add the exposure to the K3 normal ANT1 or ANT2 input if an antenna is connected. 73, Don W3FPR On 1/28/2015 7:45 AM, Doug Turnbull wrote: > Lyle and company, > To be clear are you talking about using another transmitter other than > the K3's transmitter and external amplifier? This is my reading and I am > just checking. Thank you. > > ______________________________________________________________ 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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In reply to this post by Doug Turnbull
> On Jan 28, 2015, at 7:45 AM, Doug Turnbull <[hidden email]> wrote: > > Lyle and company, > To be clear are you talking about using another transmitter other than > the K3's transmitter and external amplifier? This is my reading and I am > just checking. Thank you. Both. I believe the OP asked about the sub RX and the K3 transmitter I broadened the question because I blew out the front end on the K3 while testing another transmitter. Either situation speaks to how much the K3 receiver can take from external RF. But some solutions such as putting protective devices in front of the K3 sub receiver will not work of course when the situation involves the K3 main receiver and an external transmitter. Ken WA8JXM ______________________________________________________________ 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] |
Re: K3 Sub Receiver and protecting the Sub RX input
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In reply to this post by Don Wilhelm-4
Don,
Thank you. There is no problem so far but I will place an order with Array Solutions for a bit of additional protection. The forum is useful! Thanks to all for bringing this issue up. 73 Doug EI2CN -----Original Message----- From: Don Wilhelm [mailto:[hidden email]] Sent: 28 January 2015 13:41 To: Doug Turnbull; 'Lyle Johnson'; 'Elecraft Reflector' Subject: Re: [Elecraft] K3 Sub Receiver and protecting the Sub RX input Doug, Not necessarily - the K3 RX antenna input can be exposed to RF from the TX antenna whether that is the K3 transmitting or another transmitter. In the case of another transmitter, one can add the exposure to the K3 normal ANT1 or ANT2 input if an antenna is connected. 73, Don W3FPR On 1/28/2015 7:45 AM, Doug Turnbull wrote: > Lyle and company, > To be clear are you talking about using another transmitter other than > the K3's transmitter and external amplifier? This is my reading and I am > just checking. Thank you. > > ______________________________________________________________ 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] |
Re: K3 Sub Receiver and protecting the Sub RX input
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In reply to this post by KEN-3
Folks,
Have we lost track of our senses? (I never vent so please allow me to do so..) I like to “trade a lot" and see many radios that have a blown out front end, which usually I can fix. Most times the victim radio was “on receive” with a shiny new transmitter that was “just being set in place” into the operator position. Usually the old radio is on an antenna that was in very close proximity to the new one. Professionally I do EMC work and while I can bore you with the math… ether you connect “something” in line with the old receiver (there are lots of manufacturers out there) … or you leave the old radio disconnected when transmitting. Not too many radios are designed for 100 watts into an adjacent antenna, let alone 500W or 1kW…. This is NOT an Elecraft issue…. Sorry to vent, I love my K2’s Frank KG9H ______________________________________________________________ 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] |
Re: K3 Sub Receiver and protecting the Sub RX input
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In reply to this post by KEN-3
If the 2nd rx pre-amp can add sufficient gain, then a resistive divider on
that input will add a good degree of protection. Receive-only aerials often have their own pre-amps, so there might be plenty of gain in hand. Coax to the 2nd rx should still be protected against common mode current. David G3UNA > >> On Jan 28, 2015, at 7:45 AM, Doug Turnbull <[hidden email]> wrote: >> >> Lyle and company, >> To be clear are you talking about using another transmitter other >> than >> the K3's transmitter and external amplifier? This is my reading and I >> am >> just checking. Thank you. > > > Both. I believe the OP asked about the sub RX and the K3 transmitter I > broadened the question because I blew out the front end on the K3 while > testing another transmitter. Either situation speaks to how much the K3 > receiver can take from external RF. But some solutions such as putting > protective devices in front of the K3 sub receiver will not work of course > when the situation involves the K3 main receiver and an external > transmitter. > > Ken WA8JXM > 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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