Elecraft

Two K3's, Same Band, Same Time?

Classic

List

Threaded

10 messages Options

Dan Levin

Two K3's, Same Band, Same Time?

For Sweepstakes, we are thinking about using a large multi-multi contesting
station to house two separate single operator efforts. The station has two
yagi antennas on each band, separated by about 500 feet, and element tip to
element tip when beaming the US (antennas pointed in parallel).

The thought has crossed my mind that two K3's in such a situation might be
able to deal with the other signal, even strong and so close, if one station
is at the low end of the band (say 14005) and the other is at the high end
of the band (say 14075).

Would anyone care to weigh in about the likelihood of the receivers
surviving such behavior?

***dan, K6IF

_______________________________________________
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

Craig Rairdin

RE: Two K3's, Same Band, Same Time?

I don't know about two K3's but I can tell you that my K3 was swamped during
Field Day by the phone station operating with a beam pointed away from me,
directly off the end of my dipole, separated by about that 500' distance.
That was CW vs SSB frequency spacing.

We were ok when operating on separate bands; just not on the same band.

Craig
NZ0R
K3/100 #25
K2/100 #4941
K1 #1966
KX1 #1499

"When you spread the wealth around, it's good for everybody." -- Barack
Obama
"From each according to his ability, to each according to his need" -- Karl
Marx

"You can choose policies that invest in our middle-class and create new jobs
and grow this economy from the bottom-up." -- Barack Obama
"It will be the workers, with their courage, resolution and self-sacrifice,
who will be chiefly responsible for achieving victory." -- Karl Marx

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Dan Levin
Sent: Tuesday, October 28, 2008 11:02 PM
To: [hidden email]
Subject: [Elecraft] Two K3's, Same Band, Same Time?

For Sweepstakes, we are thinking about using a large multi-multi contesting
station to house two separate single operator efforts. The station has two
yagi antennas on each band, separated by about 500 feet, and element tip to
element tip when beaming the US (antennas pointed in parallel).

The thought has crossed my mind that two K3's in such a situation might be
able to deal with the other signal, even strong and so close, if one station
is at the low end of the band (say 14005) and the other is at the high end
of the band (say 14075).

Would anyone care to weigh in about the likelihood of the receivers
surviving such behavior?

***dan, K6IF

_______________________________________________
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

Eric Swartz - WA6HHQ

Re: Two K3's, Same Band, Same Time?

Administrator

Craig,

That may have been due to the wideband noise and other products
transmitted from the other, non-K3, station. The VP6DX guys ran two K3s
per band at 1500w for the complete time they were down on Ducie without
interference.

73, Eric WA6HHQ

_..._

Craig Rairdin wrote:

> I don't know about two K3's but I can tell you that my K3 was swamped during
> Field Day by the phone station operating with a beam pointed away from me,
> directly off the end of my dipole, separated by about that 500' distance.
> That was CW vs SSB frequency spacing.
>
> We were ok when operating on separate bands; just not on the same band.
>
> Craig
> NZ0R
> K3/100 #25
> K2/100 #4941
> K1 #1966
> KX1 #1499
>

_______________________________________________
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

Carl Clawson

RE: Two K3's, Same Band, Same Time?

In reply to this post by Dan Levin

Dan, you should be fine.

On Field Day W7OTV had two K3s, one on CW and one on digital. Antennas
fairly non-directional, about 500 ft apart. A CW op was tuning up the band
and crossed into digital territory, and didn't even notice the other K3
until he was almost right on top of him.

It was a world of difference from previous years when my trusty old ICOM 735
and a variety of lower-end Yaesu and Kenwood rigs would really clobber each
other from one end of the band to the other.

Good luck,
Carl WS7L
K3 #486

> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Dan Levin
> Sent: Tuesday, October 28, 2008 9:02 PM
> To: [hidden email]
> Subject: [Elecraft] Two K3's, Same Band, Same Time?
>
> For Sweepstakes, we are thinking about using a large
> multi-multi contesting station to house two separate single
> operator efforts. The station has two yagi antennas on each
> band, separated by about 500 feet, and element tip to element
> tip when beaming the US (antennas pointed in parallel).
>
> The thought has crossed my mind that two K3's in such a
> situation might be able to deal with the other signal, even
> strong and so close, if one station is at the low end of the
> band (say 14005) and the other is at the high end of the band
> (say 14075).
>
> Would anyone care to weigh in about the likelihood of the
> receivers surviving such behavior?
>
> ***dan, K6IF
>
> _______________________________________________
> 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 No virus found in
> this incoming message.
> Checked by AVG - http://www.avg.com
> Version: 8.0.175 / Virus Database: 270.8.4/1752 - Release
> Date: 10/28/2008 10:04 AM
>

David Cutter

Re: Re: Two K3's, Same Band, Same Time?

In reply to this post by Dan Levin

Eric

Is the phase noise performance of the K3s on Ducie the same as that from later K3s? I dimly recall that some early K3s had an issue which was later fixed. I know you had to supply their K3s quite early on in the production run, so, perhaps they are now even better.

I attended their technical talks at HFC and I must say the detail was astonishing.

David
G3UNA

>
> From: Eric Swartz WA6HHQ - Elecraft <[hidden email]>
> Date: 2008/10/29 Wed AM 04:25:46 GMT
> To: Craig Rairdin <[hidden email]>
> CC: 'Elecraft Reflector' <[hidden email]>
> Subject: Re: [Elecraft] Two K3's, Same Band, Same Time?
>
> Craig,
>
> That may have been due to the wideband noise and other products
> transmitted from the other, non-K3, station. The VP6DX guys ran two K3s
> per band at 1500w for the complete time they were down on Ducie without
> interference.
>
> 73, Eric WA6HHQ
>
> _..._
>
>

-----------------------------------------
Email sent from www.virginmedia.com/email
Virus-checked using McAfee(R) Software and scanned for spam

_______________________________________________
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

Tom Hammond-2

Re: Two K3's, Same Band, Same Time?

In reply to this post by Dan Levin

Hi Dan:

At 23:01 10/28/2008, Dan Levin wrote:

For Field Day 2008, the Mid-MO ARC ran three 100W (3) K3s.

Each K3 used a multiband dipole.

The three dipoles were all strung, end-to-end, with about 40' of space BETWEEN
ends, in order to attempt to take as much advantage as possible of
the inherent
null off the end of each dipole.

We very often found ourselves running at least two of the K3s on the same band
and a number of times, we found all three K3's on the same band (usually one
K3 on CW and the other two K3s on SSB).

While I'd be lying if I said there was NO DESENSE, I can state that the level
of desense was such than no operator (newbie or old hand) ever reported a
problem of significant front end overload or significant dense... period!
And you can bet that I'd have (eventually) heard about it if it'd been there!

The K3s performed SO MUCH BETTER than ANY other rig combinations we've used
over the years! And the attention to front end design built into the K3 has
really caused it to shine as a top performer in the presence of nearby strong
signals.

We'll be running a 2-station special event activity this coming weekend:

Halloween from Frankenstein (MISSOURI)

and the W0O special event call. We'll have two K3's operating here as well,
and we'll again be using two of the three multiband dipoles, end-to-end.
We expect no significant degradation in our ability to operate both stations
on the same band as in the past.

While this does not address QRO operation, it may help give you an idea of
what you might expect, given the proximity of the dipoles to each other.

73,

Tom Hammond N0SS

_______________________________________________
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

Eric Swartz - WA6HHQ

Re: Two K3's, Same Band, Same Time?

Administrator

In reply to this post by David Cutter

Hi David,

The low phase noise has not changed on later K3s. :-)

73, Eric WA6HHQ

_..._

[hidden email] wrote:

> Eric
>
> Is the phase noise performance of the K3s on Ducie the same as that from later K3s? I dimly recall that some early K3s had an issue which was later fixed. I know you had to supply their K3s quite early on in the production run, so, perhaps they are now even better.
>
> I attended their technical talks at HFC and I must say the detail was astonishing.
>
> David
> G3UNA
>
>

Tom-5

Re: Two K3's, Same Band, Same Time?

In reply to this post by Eric Swartz - WA6HHQ

I would try it. We had two K3's in use at the Holland (MI !) field
day site, K8DAA on 20 meters. One on phone the other on CW. Sometime we
were within 50-75 kc's , oops, kHz of each other, with no ill effect.
The antennas were maybe 200 feet apart at the most, and they were not
looking into the ends of any dipole. Compare to years past, we have had
all kinds of problems with receiver overload and transmitter noise.

tom K8TB

_______________________________________________
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

Alan Bloom

Re: Two K3's, Same Band, Same Time?

In reply to this post by Dan Levin

We used to do that kind of thing all the time in the old days of
tube-type radios. I used to keep an old Drake B-line around just for
use on Field Day. It wasn't until the advent of solid-state
fully-synthesized radios that it became impossible to do phone and CW on
the same band on FD.

The K3 has finally brought modern technology up to the performance level
we had 40 years ago. :=)

Al N1AL

On Tue, 2008-10-28 at 20:01, Dan Levin wrote:

> For Sweepstakes, we are thinking about using a large multi-multi contesting
> station to house two separate single operator efforts. The station has two
> yagi antennas on each band, separated by about 500 feet, and element tip to
> element tip when beaming the US (antennas pointed in parallel).
>
> The thought has crossed my mind that two K3's in such a situation might be
> able to deal with the other signal, even strong and so close, if one station
> is at the low end of the band (say 14005) and the other is at the high end
> of the band (say 14075).
>
> Would anyone care to weigh in about the likelihood of the receivers
> surviving such behavior?
>
> ***dan, K6IF
>
> _______________________________________________
> 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

David Cutter

Re: Re: Two K3's, Same Band, Same Time?

In reply to this post by Dan Levin

Hi Tom

Were you using linears as well?

David
G3UNA

> >
> I would try it. We had two K3's in use at the Holland (MI !) field
> day site, K8DAA on 20 meters. One on phone the other on CW. Sometime we
> were within 50-75 kc's , oops, kHz of each other, with no ill effect.
> The antennas were maybe 200 feet apart at the most, and they were not
> looking into the ends of any dipole. Compare to years past, we have had
> all kinds of problems with receiver overload and transmitter noise.
>
> tom K8TB
>
>