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Another K3 on the way

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George-122

Another K3 on the way

Ordered K3 kit May 14, no deposit. Scheduled to arrive via UPS Ground Feb 6. Me excited!

George, N4YM
Happy owner of not-for-sale K2 # 4758
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drewko

Receive antennas

I'm a bit confused about using a receive-only antenna. Comments
suggest that they could be destructive. Is it safe to use one on the
K2 (the k160rx module) and/or k3?

73,
Drew
AF2Z

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Stewart Baker

Re: Receive antennas

Drew,
Receive only antennas can really extract wanted signals out of a
mess of local electrical noise.

To be effective they need to have minimal coupling to the transmit
antenna, otherwise all the trash collected on the main antenna
appears on the receive antenna signal. This means a reasonable
distance between the two antennas which also helps to prevent
damage to the receiver front end, but with high RF power care is
needed.

A lot of receive antennas have low output so use a 20dB or so
pre-amp. It is possible that this could be killed with RF, long
before the rig suffers. Y.M.M.V.

73
Stewart G3RXQ

On Sat, 02 Feb 2008 10:38:36 -0500, [hidden email] wrote:
> I'm a bit confused about using a receive-only antenna. Comments
> suggest that they could be destructive. Is it safe to use one on
the

> K2 (the k160rx module) and/or k3?
>
> 73,
> Drew
> AF2Z
>
> _______________________________________________
> Elecraft mailing list
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dj7mgq

Re: Receive antennas

In reply to this post by drewko

Hi Drew,

> I'm a bit confused about using a receive-only antenna. Comments
> suggest that they could be destructive. Is it safe to use one on the
> K2 (the k160rx module) and/or k3?

It all depends on how much power is coming back on the RX antenna.

If you run highish power you need to check for this, because in some
situations I have seen well over 1W coming back into the radio via the
RX antenna.

This applies to almost all radios, because most transceivers do not
disconnect the RX only antenna from the RX front end, when the radio
transmits.

If you do it properly, it is no problem whatsoever with the K2 and K3,
i.e. be sure the amount of power on the RX input stays low at all times.

vy 73 de toby
--
DD5FZ (ex 4n6fz, dj7mgq, dg5mgq, dd5fz)
K2/10 #885
K2/100 #3248
K3/100 #67
DOK C12, BCC, DL-QRP-AG, JN58td
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Rolf G

Re: Receive antennas

In reply to this post by Stewart Baker

Stewart Baker skrev:

> Drew,
> Receive only antennas can really extract wanted signals out of a
> mess of local electrical noise.
>
> To be effective they need to have minimal coupling to the transmit
> antenna, otherwise all the trash collected on the main antenna
> appears on the receive antenna signal. This means a reasonable
> distance between the two antennas which also helps to prevent
> damage to the receiver front end, but with high RF power care is
> needed.
>
> A lot of receive antennas have low output so use a 20dB or so
> pre-amp. It is possible that this could be killed with RF, long
> before the rig suffers. Y.M.M.V.
>
> 73
> Stewart G3RXQ
>
> On Sat, 02 Feb 2008 10:38:36 -0500, [hidden email] wrote:
>
>> I'm a bit confused about using a receive-only antenna. Comments
>> suggest that they could be destructive. Is it safe to use one on
>>
> the
>
>> K2 (the k160rx module) and/or k3?
>>
>> 73,
>> Drew
>> AF2Z
>>
>> _______________________________________________
>> Elecraft mailing list
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>>
>
>
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>

Hi all,

I am looking for a receive antenna for 80 meter because of
high levels of white nise here in Stockholm City.
Any suggestions there to find good building instructions on
the Internet should be appreciated.

Best 73's,
Rolf - K2 #4979
SMØYQC
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n6wg

Re: Receive antennas

Hello Rolf
Look at this web site for info on the Flag and Pennant receiving
loops. They really work.
http://www.angelfire.com/md/k3ky/page37.html

Also, check out the K9AY loops at
http://www.aytechnologies.com/TechData/LoopInstall.htm

Good luck and 73
Bob N6WG

----- Original Message -----
From: "TWC" <[hidden email]>
To: "Stewart Baker" <[hidden email]>
Cc: <[hidden email]>
Sent: Saturday, February 02, 2008 10:47 AM
Subject: Re: [Elecraft] Receive antennas

> Stewart Baker skrev:
> > Drew,
> > Receive only antennas can really extract wanted signals out of a
> > mess of local electrical noise.
> >
> > To be effective they need to have minimal coupling to the transmit
> > antenna, otherwise all the trash collected on the main antenna
> > appears on the receive antenna signal. This means a reasonable
> > distance between the two antennas which also helps to prevent
> > damage to the receiver front end, but with high RF power care is
> > needed.
> >
> > A lot of receive antennas have low output so use a 20dB or so
> > pre-amp. It is possible that this could be killed with RF, long
> > before the rig suffers. Y.M.M.V.
> >
> > 73
> > Stewart G3RXQ
> >
> > On Sat, 02 Feb 2008 10:38:36 -0500, [hidden email] wrote:
> >
> >> I'm a bit confused about using a receive-only antenna. Comments
> >> suggest that they could be destructive. Is it safe to use one on
> >>
> > the
> >
> >> K2 (the k160rx module) and/or k3?
> >>
> >> 73,
> >> Drew
> >> AF2Z
> >>
> >> _______________________________________________
> >> Elecraft mailing list
> >> Post to: [hidden email]
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> >> Subscriber Info (Addr. Change, sub, unsub etc.):
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> >>
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> >>
> >
> >
> > _______________________________________________
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> >
> >
> Hi all,
>
> I am looking for a receive antenna for 80 meter because of
> high levels of white nise here in Stockholm City.
> Any suggestions there to find good building instructions on
> the Internet should be appreciated.
>
> Best 73's,
> Rolf - K2 #4979
> SMØYQC
> _______________________________________________
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> Post to: [hidden email]
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> Elecraft web page: http://www.elecraft.com

Stewart Baker

Re: Receive antennas

I am using 2 Pennant antennas for 160 and 80. They work very well.
Follow the link.

73
Stewart G3RXQ
On Sat, 2 Feb 2008 11:29:12 -0800, Robert Tellefsen wrote:

> Hello Rolf
> Look at this web site for info on the Flag and Pennant receiving
> loops. They really work.
> http://www.angelfire.com/md/k3ky/page37.html
>
> Also, check out the K9AY loops at
> http://www.aytechnologies.com/TechData/LoopInstall.htm
>
> Good luck and 73
> Bob N6WG
>
> ----- Original Message -----
> From: "TWC" <[hidden email]>
> To: "Stewart Baker" <[hidden email]>
> Cc: <[hidden email]>
> Sent: Saturday, February 02, 2008 10:47 AM
> Subject: Re: [Elecraft] Receive antennas
>
>
>> Stewart Baker skrev:
>>> Drew,
>>> Receive only antennas can really extract wanted signals out of

a
>>> mess of local electrical noise.
>>>
>>> To be effective they need to have minimal coupling to the
transmit
>>> antenna, otherwise all the trash collected on the main antenna
>>> appears on the receive antenna signal. This means a reasonable
>>> distance between the two antennas which also helps to prevent
>>> damage to the receiver front end, but with high RF power care
is
>>> needed.
>>>
>>> A lot of receive antennas have low output so use a 20dB or so
>>> pre-amp. It is possible that this could be killed with RF,
long
>>> before the rig suffers. Y.M.M.V.
>>>
>>> 73
>>> Stewart G3RXQ
>>>
>>> On Sat, 02 Feb 2008 10:38:36 -0500, [hidden email] wrote:
>>>
>>>> I'm a bit confused about using a receive-only antenna.
Comments
>>>> suggest that they could be destructive. Is it safe to use one
on

>>>>
>>> the
>>>
>>>> K2 (the k160rx module) and/or k3?
>>>>
>>>> 73,
>>>> Drew
>>>> AF2Z
>>>>
>>>> _______________________________________________
>>>> Elecraft mailing list
>>>> Post to: [hidden email]
>>>> You must be a subscriber to post to the list.
>>>> Subscriber Info (Addr. Change, sub, unsub etc.):
>>>> http://mailman.qth.net/mailman/listinfo/elecraft
>>>>
>>>> Help: http://mailman.qth.net/subscribers.htm
>>>> Elecraft web page: http://www.elecraft.com
>>>
>>>
>>> _______________________________________________
>>> Elecraft mailing list
>>> Post to: [hidden email]
>>> You must be a subscriber to post to the list.
>>> Subscriber Info (Addr. Change, sub, unsub etc.):
>>> http://mailman.qth.net/mailman/listinfo/elecraft
>>>
>>> Help: http://mailman.qth.net/subscribers.htm
>>> Elecraft web page: http://www.elecraft.com
>>>
>>>
>> Hi all,
>>
>> I am looking for a receive antenna for 80 meter because of
>> high levels of white nise here in Stockholm City.
>> Any suggestions there to find good building instructions on
>> the Internet should be appreciated.
>>
>> Best 73's,
>> Rolf - K2 #4979
>> SMØYQC
>> _______________________________________________
>> Elecraft mailing list
>> Post to: [hidden email]
>> You must be a subscriber to post to the list.
>> Subscriber Info (Addr. Change, sub, unsub etc.):
>> http://mailman.qth.net/mailman/listinfo/elecraft
>>
>> Help: http://mailman.qth.net/subscribers.htm
>> Elecraft web page: http://www.elecraft.com

dj7mgq

Re: Receive antennas

In reply to this post by dj7mgq

Hi Jerry,

> Does the K3 have a protective device ("fuse") in case power coming in on
> the receive only antenna is too great?

The K3 is better protected than many other transceivers:

<http://www.elecraft.com/manual/K3%20Schematics.pdf>

and

<http://www.elecraft.com/K3/K3FAQ.htm#Front%20end%20protection>.

Nonetheless there have been reports of returning power causing problems
in the transmitter. We haven't observed this here in Bavaria, so I can
not really say very much about this. If you search the list archives,
you should be able to find more information.

vy 73 de toby
--
DD5FZ (ex 4n6fz, dj7mgq, dg5mgq, dd5fz)
K2/10 #885
K2/100 #3248
K3/100 #67
DOK C12, BCC, DL-QRP-AG, JN58td
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Chris Kantarjiev K6DBG

Re: Receive antennas

In reply to this post by drewko

Here's another site for low-band receive antennas:

http://www.qsl.net/kc2tx/

73 de chris K6DBG
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WILLIS COOKE

Re: Receive antennas

In reply to this post by Rolf G

-Rolf, the best antenna for receiving on 80 meters is
the Beverage if you have the room. Since you need to
stretch a wire for 500 to 1200 feet in the direction
that you want to receive, and live in Stockholm City,
chances are good that you don't. Instructions are in
the ARRL Antenna Book.

Failing that, you might consider a EWE if you have
room for an array that is about 30 meters square.
Instructions are at www.ok1rr.com

If you don't have room for an EWE, you can look at a
K9AY array which was published in QST and is available
on the internet. It requires a space about 15 feet
in diameter.

If you have lots of money to spend, look at the DX
Engineering four square receiving array.

Cookie, K5EWJ

> Hi all,
>
> I am looking for a receive antenna for 80 meter
> because of
> high levels of white nise here in Stockholm City.
> Any suggestions there to find good building
> instructions on
> the Internet should be appreciated.
>
> Best 73's,
> Rolf - K2 #4979
> SMØYQC
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
>
>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>

Stewart Baker

Re: Receive antennas

Note. The EWE needs good and consistent ground conditions to work
well.

Stewart G3RXQ
On Sat, 2 Feb 2008 16:19:56 -0800 (PST), WILLIS COOKE wrote:

>
> -Rolf, the best antenna for receiving on 80 meters is
> the Beverage if you have the room. Since you need to
> stretch a wire for 500 to 1200 feet in the direction
> that you want to receive, and live in Stockholm City,
> chances are good that you don't. Instructions are in
> the ARRL Antenna Book.
>
> Failing that, you might consider a EWE if you have
> room for an array that is about 30 meters square.
> Instructions are at www.ok1rr.com
>
> If you don't have room for an EWE, you can look at a
> K9AY array which was published in QST and is available
> on the internet. It requires a space about 15 feet
> in diameter.
>
> If you have lots of money to spend, look at the DX
> Engineering four square receiving array.
>
> Cookie, K5EWJ
>> Hi all,
>>
>> I am looking for a receive antenna for 80 meter
>> because of
>> high levels of white nise here in Stockholm City.
>> Any suggestions there to find good building
>> instructions on
>> the Internet should be appreciated.
>>
>> Best 73's,
>> Rolf - K2 #4979
>> SMØYQC
>> _______________________________________________
>> Elecraft mailing list
>> Post to: [hidden email]
>> You must be a subscriber to post to the list.
>> Subscriber Info (Addr. Change, sub, unsub etc.):
>> http://mailman.qth.net/mailman/listinfo/elecraft
>>
>>
>> Help: http://mailman.qth.net/subscribers.htm
>> Elecraft web page: http://www.elecraft.com

Parker Buckley

Re: Receive Antennas

In reply to this post by drewko

I was interested to read recent comments on 160M receive antennas. As it
happens, I just completed a coaxial loop antenna for my K2 this weekend, as
described by KN4LF and KC2TX, and combined it with their recommended preamp.
It's the antenna design that's been in the handbook for years. I've wanted
to try one of these for some time, thinking I might hear that rare DX that
everyone else seems to be working. So it's all tuned up and seems to work
well, but let me ask a basic question. If I already enjoy relatively quiet
conditions on 160, in spite of living in the city, will the loop ever hear
anything that my full-sized inverted L won't hear? The inverted L seems to
work well, as I've worked all over the US, including Hawaii, during
contests; all the while at 5 watts (I know, it's all about their beverage
and not my whopping signal, but still I'm pretty happy for QRP). My nominal
noise level on the L is 2 S units. I peaked up the K2 and measured receive
sensitivity, and I think it's doing all that it should. So is this loop
antenna just a fun project, or will this let me hear things so far down in
the noise that I would not other wise hear them?

Parker WD8JOL K2 #2636

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n6wg

Re: Re: Receive Antennas

Hi Parker
I think it depends on the noise source. If it comes from one
direction, a loop antenna can be rotated to place its null on the
noise source, improving the signal to noise ratio for the signals
coming from other directions.

On the other hand, if your noise is more pervasive, and turning
the loop won't reduce it, the loop isn't going to do anything
for you. You might as well stay with your main antenna. One
thing you can try that helps sometimes is use an existing
dipole for reception on 160m or 80. As horizontally
polarized antennas, they will have a different noise pickup than
the inv. L. Sometimes this can make a useful difference.

All receiving loops I know of have less signal pickup than any
full size antenna, such as your inv. L. Larger loops may get
by without use of a preamp other than what is already in your
receiver. However, the lower in frequency you go, the less
signal pickup the loop will have and will probably benefit
from a preamp. Homebrew preamps are easy to make, and an
Altoids tin makes a great housing. I've built several that way,
and they all do just what is needed.

By all means, give a loop a try. They are easy to make and
inexpensive. A great cheap experiment. If it seems to do a
useful job, then by all means make a more permanent version.

Good luck and 73
Bob N6WG

----- Original Message -----
From: "Parker Buckley" <[hidden email]>
To: <[hidden email]>
Sent: Sunday, February 03, 2008 2:33 PM
Subject: [Elecraft] Re: Receive Antennas

> I was interested to read recent comments on 160M receive antennas.
As it
> happens, I just completed a coaxial loop antenna for my K2 this
weekend, as
> described by KN4LF and KC2TX, and combined it with their recommended
preamp.
> It's the antenna design that's been in the handbook for years. I've
wanted
> to try one of these for some time, thinking I might hear that rare
DX that
> everyone else seems to be working. So it's all tuned up and seems
to work
> well, but let me ask a basic question. If I already enjoy
relatively quiet
> conditions on 160, in spite of living in the city, will the loop
ever hear
> anything that my full-sized inverted L won't hear? The inverted L
seems to
> work well, as I've worked all over the US, including Hawaii, during
> contests; all the while at 5 watts (I know, it's all about their
beverage
> and not my whopping signal, but still I'm pretty happy for QRP). My
nominal
> noise level on the L is 2 S units. I peaked up the K2 and measured
receive
> sensitivity, and I think it's doing all that it should. So is this
loop
> antenna just a fun project, or will this let me hear things so far
down in

> the noise that I would not other wise hear them?
>
> Parker WD8JOL K2 #2636
>
> _______________________________________________
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