[Elecraft] Protecting the Sub RX input

[Ken G Kopp]

I have one of the Array Solutions units protecting my K3.  FWIW,  I have a
KPA500 and a number of antennas on a two acre lot. Translates to lots of
cross-coupling.

73

Ken - K0PP
On Jan 27, 2015 7:11 PM, "dmb at lightstream.net" <dmb at lightstream.net> wrote:

> 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
> >
> >
>
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