[Elecraft] Rec antenna protection

[Chris Hallinan]

I''ve been somewhat frustrated with the same issue.  I purchased the Array
Solutions (AS)  Front End Protector, as you mention.  When I first
connected it, I was treated with terrible noise and images all over the 20
meter and 40 meter bands.  I returned the unit to AS, and they tested it
and found no problems.  After further investigation, I discovered that the
RXFEP was being overloaded by broadcast signals, both from the US
Commercial AM broadcast band (550 to 1600KHz) as well as very strong
signals from some short wave broadcasters. These short wave stations are on
5 MHz and believe it or not, even one station in Alabama transmitting on
13.830, which pegs my K3's S-meter at +60dB over S9 at certain times of the
day depending on conditions and the orientation of my RX loop.  All of
these together overload the RXFEP.  Putting my antenna into a scope input,
I can see more than 2 volts p-p during the day, and up to 5 volts p-p at
night!!!  If I did my calculations right, that's around +18 dBm!

So then I purchased the receive-only broadcast filter from AS, and that
improved my situation 95%.  Now I need to eliminate the energy from the
other 5, 12 and 13 MHz broadcasters.

Even with the RXFEP installed, I still have COR clicking on 40 meters,
likely due to the proximity of my Rx Loop to my 40-meter vertical.  I HATE
relay clicks, and LOVE the fact that the K3 is such a great CW rig with
silent TR switching.  But...the only solution so far I've found is to
connect the K3 key out jack to the power tap from my Inlogis Rx Loop.
Unfortunately, that is a relay, and gives me audible clicks when I send CW.

I am in the process of further investigation/testing, and I'm going to try
some bandbass filters to see if I can alleviate the overloading issue.  But
I might also be forced to relocate my loop or vertical to eliminate the
need to use a relay in the rx antenna circuit.

I would appreciate hearing about other's experiences.

73,

Chris
K1AY

disclaimer: I don't mean to bash Array Solutions.  I think the AS-RXFEP is
a great product, and AS has other great products.  Best money I ever spent
in amateur radio was my recent purchase of the AS AIM4300.

On Thu, Aug 6, 2015 at 12:40 PM, Nr4c <nr4c at widomaker.com> wrote:

> I'm looking for a device to protect my K3S front end when using a RX
> antenna. As I key my rig I can hear the COR clicking and it's making me
> nervous.
>
> I have seen the AS-RXFEP review by W1ZR in QST.  I have also seen devices
> with reed relays on the web. What are you using or am I just foolish to
> worry about this?
>
>
> Sent from my iPhone
> ...nr4c. bill
>
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