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K3 6-meter Performance Question

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Terry Schieler

K3 6-meter Performance Question

Fellow Elecraftorians:

Some weeks back I recall a post here that the K3 6-meter performance did not
seem to be up to par with its HF band performance as well as that of some of
the other HF thru 6 rigs on the market, and there was some related
discussion regarding a future accessory receive pre-amp for six. If I
recall correctly, Wayne or Eric popped in to state the reason for the
difference in performance, so it was, apparently, a documented situation.

I have searched for the specific posts with no avail. But it leads me to
ask whether I should hang on to my XV-50 transverter (which I had planned to
sell) or use it with my K3 for its improved performance. Has anyone done
this? Id be interested in your comments.

73,

Terry, WØFM

K2 3716

K3 474

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Ken Kopp-3

K3 6-meter Performance Question

Terry,

In the event you missed my previous post ...

I live in a quiet rural setting and when I connect my 6M
1/4 wave GP my noise rises. That tells me ... at least at
my location ... that more gain / "better" receive would be
of little help.

73! Ken Kopp - K0PP
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Stewart Baker

Re: K3 6-meter Performance Question

In reply to this post by Terry Schieler

I would hang on to your XV-50 until you have checked that you find
your K3 sensitive enough on 6m. I made the mistake of selling mine
off before my K3 arrived, and I now regret it.

73
Stewart G3RXQ
On Mon, 23 Jun 2008 13:19:51 -0500, Terry Schieler wrote:
> Fellow Elecraftorians:
>
>
> Some weeks back I recall a post here that the K3 6-meter
performance did not
> seem to be up to par with its HF band performance as well as
that of some of
> the other HF thru 6 rigs on the market, and there was some
related
> discussion regarding a future accessory receive pre-amp for six.
If I
> recall correctly, Wayne or Eric popped in to state the reason
for the
> difference in performance, so it was, apparently, a documented
situation.
>
>
> I have searched for the specific posts with no avail. But it
leads me to
> ask whether I should hang on to my XV-50 transverter (which I
had planned to
> sell) or use it with my K3 for its improved performance. Has
anyone done

> this? I'd be interested in your comments.
>
>
> 73,
>
>
> Terry, WØFM
>
>
> K2 3716
>
> K3 474
>
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
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Dick Hanson

RE: K3 6-meter Performance Question

Ciao, from CY0X, Sable Island.....

Well, let's see now, is the K3 sensitive enuff for serious weak sig work on
six.
Based on our first week here on Sable, doing mostly weak signal work, I
could not be more pleased.
We were fortunate to have been given one of the prototype preamps to use
ahead of the radio on six, and I can tell you that it has been an excellent
addition.
We have been monitoring many of the EU TV offsets, world-wide beacons and of
course listening for many of the signals from across the pond.

Consider this: we are running approx 800 watts into a 12dbd ant at 70' ASL,
surrounded by salt water; we have zero man-made noise towards EU, AF and
Asia, so we are hearing very well. Many of the stations we are working in EU
do not have as much power or antenna; hence many of them hear us better than
we hear them. Yet, we have logged nearly 2500 contacts thus far in 60 dxcc.
My conclusion is that we are not suffering from a hearing loss.

Since it is so easy to switch out the outboard preamp, we have frequently
done this on some of the weak sigs just to see if we could still hear them.
In many cases we could hear them Q5 with just the internal preamp. Ian,
GM3SEK, et al, have pointed out that the stock radio NF is somewhere in the
8-10db range, which is not stellar as six meter radio specs go. Nonetheless,
you'd be surprised at how many weak sigs we can still hear with only the
internal preamp engaged.

I also have the XV50, and will keep it, but that is because I tend to keep
my radio gadgets a long time.

FWIW: we love the K3 and how it performs on six. Hopefully, we have already
worked a number of you. If you haven't yet made contact, please check our
website at www.cy0x.com and then stop by 50108 and give us a call.

73,
Dick
K5AND/CY0X

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Bill VanAlstyne W5WVO

Re: K3 6-meter Performance Question

One fact that does seem to get missed by many 6m operators is that ambient
noise is very much relative to where you are. Dick makes this very clear.
The old test of disconnecting and reconnecting your antenna to see if the
antenna noise level is perceptible is a good rule of thumb -- but that's
all. Noise is additive. If you have a front end with a crummy noise figure
on 6m, but you do hear the noise level increase modestly when you connect
the antenna by a couple dB -- you will *still* probably benefit from a
preamp with a much better noise figure, because the receiver-based noise you
were hearing with the antenna disconnected is a significant portion of your
overall noise floor when the antenna is connected.

On the other hand, if your total noise floor goes up 7-10 dB when you
connect the antenna, that's perhaps a different matter. This is how much
*my* noise level goes up -- on a *good* day. Will I benefit from a
super-low-noise preamp, as did the CY0X expedition? Maybe not so much. :-)
Again, it depends on how much my existing receiver is contributing to my
overall ambient noise floor.

All I can say to those guys who need 20 dB of gain and a hushed noise figure
to be able to hear any antenna noise on 6m... I envy you more than I can
say! My guess is, however, that my situation is more comparable to the vast
majority of 6m hams living in a typical US metro area.

The whole point of this is simply that the question of "how much RF gain is
enough" and "how good a noise figure is good enough" is *extremely*
relative. I wish it weren't so, but that's the reality. The only reliable
way to see if an LNA will help in your situation is to try it. Which is
exactly what I plan to do. :-)

Bill W5WVO

----- Original Message -----
From: "Dick Hanson" <[hidden email]>
To: "'Stewart Baker'" <[hidden email]>; "'Elecraft Reflector'"
<[hidden email]>
Sent: Tuesday, July 01, 2008 3:19 AM
Subject: RE: [Elecraft] K3 6-meter Performance Question

> Ciao, from CY0X, Sable Island.....
>
> Well, let's see now, is the K3 sensitive enuff for serious weak sig work
on
> six.
> Based on our first week here on Sable, doing mostly weak signal work, I
> could not be more pleased.
> We were fortunate to have been given one of the prototype preamps to use
> ahead of the radio on six, and I can tell you that it has been an
excellent
> addition.
> We have been monitoring many of the EU TV offsets, world-wide beacons and
of
> course listening for many of the signals from across the pond.
>
> Consider this: we are running approx 800 watts into a 12dbd ant at 70'
ASL,
> surrounded by salt water; we have zero man-made noise towards EU, AF and
> Asia, so we are hearing very well. Many of the stations we are working in
EU
> do not have as much power or antenna; hence many of them hear us better
than
> we hear them. Yet, we have logged nearly 2500 contacts thus far in 60
dxcc.
> My conclusion is that we are not suffering from a hearing loss.
>
> Since it is so easy to switch out the outboard preamp, we have frequently
> done this on some of the weak sigs just to see if we could still hear
them.
> In many cases we could hear them Q5 with just the internal preamp. Ian,
> GM3SEK, et al, have pointed out that the stock radio NF is somewhere in
the
> 8-10db range, which is not stellar as six meter radio specs go.
Nonetheless,
> you'd be surprised at how many weak sigs we can still hear with only the
> internal preamp engaged.
>
> I also have the XV50, and will keep it, but that is because I tend to keep
> my radio gadgets a long time.
>
> FWIW: we love the K3 and how it performs on six. Hopefully, we have
already

> worked a number of you. If you haven't yet made contact, please check our
> website at www.cy0x.com and then stop by 50108 and give us a call.
>
> 73,
> Dick
> K5AND/CY0X
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
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>
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> Elecraft web page: http://www.elecraft.com

S Sacco

Re: K3 6-meter Performance Question

In reply to this post by Dick Hanson

Dick -

I'm running a 7/7 stack, at 160'/140'. Separately, I have a Hy-Gain
66DX fixed NNE at 90'.

Switching beteen either of the above antennas and no antenna, I
generally hear no increase in background noise level on my K3. Not a
good sign. When I had an ICOM IC-756ProII, and, before that, a Yaesu
FT-920, that was not the case.

I'm looking forward to receiving the K3 6M pre-amp.

73,
Steve NN4X

On 7/1/08, Dick Hanson <[hidden email]> wrote:

> Ciao, from CY0X, Sable Island.....
>
> Well, let's see now, is the K3 sensitive enuff for serious weak sig work on
> six.
> Based on our first week here on Sable, doing mostly weak signal work, I
> could not be more pleased.
> We were fortunate to have been given one of the prototype preamps to use
> ahead of the radio on six, and I can tell you that it has been an excellent
> addition.
> We have been monitoring many of the EU TV offsets, world-wide beacons and of
> course listening for many of the signals from across the pond.
>
> Consider this: we are running approx 800 watts into a 12dbd ant at 70' ASL,
> surrounded by salt water; we have zero man-made noise towards EU, AF and
> Asia, so we are hearing very well. Many of the stations we are working in EU
> do not have as much power or antenna; hence many of them hear us better than
> we hear them. Yet, we have logged nearly 2500 contacts thus far in 60 dxcc.
> My conclusion is that we are not suffering from a hearing loss.
>
> Since it is so easy to switch out the outboard preamp, we have frequently
> done this on some of the weak sigs just to see if we could still hear them.
> In many cases we could hear them Q5 with just the internal preamp. Ian,
> GM3SEK, et al, have pointed out that the stock radio NF is somewhere in the
> 8-10db range, which is not stellar as six meter radio specs go. Nonetheless,
> you'd be surprised at how many weak sigs we can still hear with only the
> internal preamp engaged.
>
> I also have the XV50, and will keep it, but that is because I tend to keep
> my radio gadgets a long time.
>
> FWIW: we love the K3 and how it performs on six. Hopefully, we have already
> worked a number of you. If you haven't yet made contact, please check our
> website at www.cy0x.com and then stop by 50108 and give us a call.
>
> 73,
> Dick
> K5AND/CY0X
>
> _______________________________________________
> 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
>

Lee J. Imber (WW2DX)

Re: K3 6-meter Performance Question

In reply to this post by Dick Hanson

Thanks Dick for the new one on 6. You guys are doing a great job.

http://www.youtube.com/watch?v=NBF3Q4xrnjA

K3 to K3 Q?

Can you give a little info on the protoype preamp? external? how is it
powered? pics?

ok ok, you can answer all that when 6 dies down ;)

Thanks!

Lee
WW2DX

On Jul 1, 2008, at 5:19 AM, Dick Hanson wrote:

> Ciao, from CY0X, Sable Island.....
>
> Well, let's see now, is the K3 sensitive enuff for serious weak sig
> work on
> six.
> Based on our first week here on Sable, doing mostly weak signal
> work, I
> could not be more pleased.
> We were fortunate to have been given one of the prototype preamps to
> use
> ahead of the radio on six, and I can tell you that it has been an
> excellent
> addition.
> We have been monitoring many of the EU TV offsets, world-wide
> beacons and of
> course listening for many of the signals from across the pond.
>
> Consider this: we are running approx 800 watts into a 12dbd ant at
> 70' ASL,
> surrounded by salt water; we have zero man-made noise towards EU, AF
> and
> Asia, so we are hearing very well. Many of the stations we are
> working in EU
> do not have as much power or antenna; hence many of them hear us
> better than
> we hear them. Yet, we have logged nearly 2500 contacts thus far in
> 60 dxcc.
> My conclusion is that we are not suffering from a hearing loss.
>
> Since it is so easy to switch out the outboard preamp, we have
> frequently
> done this on some of the weak sigs just to see if we could still
> hear them.
> In many cases we could hear them Q5 with just the internal preamp.
> Ian,
> GM3SEK, et al, have pointed out that the stock radio NF is somewhere
> in the
> 8-10db range, which is not stellar as six meter radio specs go.
> Nonetheless,
> you'd be surprised at how many weak sigs we can still hear with only
> the
> internal preamp engaged.
>
> I also have the XV50, and will keep it, but that is because I tend
> to keep
> my radio gadgets a long time.
>
> FWIW: we love the K3 and how it performs on six. Hopefully, we have
> already
> worked a number of you. If you haven't yet made contact, please
> check our
> website at www.cy0x.com and then stop by 50108 and give us a call.
>
> 73,
> Dick
> K5AND/CY0X
>
> _______________________________________________
> 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

gm3sek

Re: K3 6-meter Performance Question

In reply to this post by Dick Hanson

On Tuesday, Dick K5AND wrote:

>Ciao, from CY0X, Sable Island.....
[...]
>
>Since it is so easy to switch out the outboard preamp, we have frequently
>done this on some of the weak sigs just to see if we could still hear them.
>In many cases we could hear them Q5 with just the internal preamp. Ian,
>GM3SEK, et al, have pointed out that the stock radio NF is somewhere in the
>8-10db range, which is not stellar as six meter radio specs go. Nonetheless,
>you'd be surprised at how many weak sigs we can still hear with only the
>internal preamp engaged.
>
That's not surprising at all, as the K3 is only slightly lacking in
sensitivity on 6m. But contrary to other reports from users in very
quiet sites, my stock K3 can NOT hear background noise at 50MHz.

Before making that statement, I took a couple of days to confirm that
nothing else is wrong with the system. Receiver sensitivity meets
Elecraft's 'typical' specification with a few dB to spare. Feeder loss
was re-measured. And above all, I re-confirmed that my old IC-746 CAN
hear background noise from the same antenna/feedline with a comfortable
3-5dB margin.

A good operator like Dick can often make up for a few dB lacking in
signal/noise ratio... but only at the expense of greater operator
fatigue, and with the knowledge that some marginal QSOs *will* be lost,
when a more sensitive receiver could have pulled them through. That is
precisely why the receiver at CY0X has a prototype Elecraft preamp.

One small correction: Elecraft's specification for a typical MDS (noise
floor) of -136dBm in a noise bandwidth of 500Hz corresponds to a noise
figure of about 13dB (significantly more than 8-10dB). Cutting through
the technicalities, at a genuinely quiet 6m site that deficit *is*
noticeable - a gap in the K3's otherwise all-round excellence.

--

73 from Ian GM3SEK
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Stewart Baker

Re: K3 6-meter Performance Question

I have just finished putting together, and testing a 6m preamp kit
from Down East Microwave. As I use the RX Ant input on the lower
bands, and not wanting to put in a relay, I have made up a
Diplexer to separate out the 2 signal paths.

Although the arrangement is a bit of a lash up it has proved the
concept, and it's worth during a short 6m opening the other
evening.

Without the preamp I noticed no discernible different in the K3
noise level when connecting the antenna. With the preamp I get
about an S2-3 indication.

More importantly signals which were there but not readable, with
the preamp they gave 100% copy.

I think that my present preamp gain at around 22dB is a little
excessive, so I will drop it back to about 15dB or so.

Before I get swamped with requests etc, I should stress that my
arrangement is not really reproducible, and you should wait until
Elecraft releases their preamp solution.

Y.M.M.V

73
Stewart G3RXQ

On Thu, 3 Jul 2008 08:50:03 +0100, Ian White GM3SEK wrote:
> On Tuesday, Dick K5AND wrote:
>
>> Ciao, from CY0X, Sable Island.....
> [...]
>
>> Since it is so easy to switch out the outboard preamp, we have
frequently
>> done this on some of the weak sigs just to see if we could
still hear them.
>> In many cases we could hear them Q5 with just the internal
preamp. Ian,
>> GM3SEK, et al, have pointed out that the stock radio NF is
somewhere in the
>> 8-10db range, which is not stellar as six meter radio specs go.
Nonetheless,
>> you'd be surprised at how many weak sigs we can still hear with
only the
>> internal preamp engaged.
>>
> That's not surprising at all, as the K3 is only slightly lacking
in
> sensitivity on 6m. But contrary to other reports from users in
very
> quiet sites, my stock K3 can NOT hear background noise at 50MHz.
>
> Before making that statement, I took a couple of days to confirm
that
> nothing else is wrong with the system. Receiver sensitivity
meets
> Elecraft's 'typical' specification with a few dB to spare.
Feeder loss
> was re-measured. And above all, I re-confirmed that my old
IC-746 CAN
> hear background noise from the same antenna/feedline with a
comfortable
> 3-5dB margin.
>
> A good operator like Dick can often make up for a few dB lacking
in
> signal/noise ratio... but only at the expense of greater
operator
> fatigue, and with the knowledge that some marginal QSOs *will*
be lost,
> when a more sensitive receiver could have pulled them through.
That is
> precisely why the receiver at CY0X has a prototype Elecraft
preamp.
>
> One small correction: Elecraft's specification for a typical MDS
(noise
> floor) of -136dBm in a noise bandwidth of 500Hz corresponds to a
noise
> figure of about 13dB (significantly more than 8-10dB). Cutting
through
> the technicalities, at a genuinely quiet 6m site that deficit
*is*
> noticeable - a gap in the K3's otherwise all-round excellence.

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alsopb

Re: K3 6-meter Performance Question

In reply to this post by gm3sek

Ian,

One also needs perhaps 10db of noise "headroom" for modes like JT65
which copy many db below the noise.
My opinion is the an internal option for this preamp is needed.
Dangling still another box with the attendent extra cables outside the
K3 isn't desirable here. Yes the preamp does handle the LF rx antenna--
still more complication.

Perhaps Elecraft can come up with both an internal and external fix and
let the market decide. I'd like nothing better than pushing the preamp
button and getting a souped up 6M preamp without more external junk.

However Elecraft knows the guts of the K3 and perhaps an internal fix
isn't practical. At least it would be nice to know that.

Of course the best place for a preamp is at the antenna. However, the
problems that generates when one is running high power introduces even
more complexity.

73 de Brian/K3KO

Ian White GM3SEK wrote:

> On Tuesday, Dick K5AND wrote:
>
>> Ciao, from CY0X, Sable Island.....
>
> [...]
>
>>
>> Since it is so easy to switch out the outboard preamp, we have
>> frequently
>> done this on some of the weak sigs just to see if we could still hear
>> them.
>> In many cases we could hear them Q5 with just the internal preamp. Ian,
>> GM3SEK, et al, have pointed out that the stock radio NF is somewhere
>> in the
>> 8-10db range, which is not stellar as six meter radio specs go.
>> Nonetheless,
>> you'd be surprised at how many weak sigs we can still hear with only the
>> internal preamp engaged.
>>
> That's not surprising at all, as the K3 is only slightly lacking in
> sensitivity on 6m. But contrary to other reports from users in very
> quiet sites, my stock K3 can NOT hear background noise at 50MHz.
>
> Before making that statement, I took a couple of days to confirm that
> nothing else is wrong with the system. Receiver sensitivity meets
> Elecraft's 'typical' specification with a few dB to spare. Feeder loss
> was re-measured. And above all, I re-confirmed that my old IC-746 CAN
> hear background noise from the same antenna/feedline with a
> comfortable 3-5dB margin.
>
> A good operator like Dick can often make up for a few dB lacking in
> signal/noise ratio... but only at the expense of greater operator
> fatigue, and with the knowledge that some marginal QSOs *will* be
> lost, when a more sensitive receiver could have pulled them through.
> That is precisely why the receiver at CY0X has a prototype Elecraft
> preamp.
>
> One small correction: Elecraft's specification for a typical MDS
> (noise floor) of -136dBm in a noise bandwidth of 500Hz corresponds to
> a noise figure of about 13dB (significantly more than 8-10dB). Cutting
> through the technicalities, at a genuinely quiet 6m site that deficit
> *is* noticeable - a gap in the K3's otherwise all-round excellence.
>
>

Ian White GM3SEK wrote: