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K144XV for K3 NF = 1dB

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Eric Swartz - WA6HHQ

K144XV for K3 NF = 1dB

Administrator

A correction to our initial spec's on the K144XV 2M module for theK3.
There was a miscalculation of its Noise Figure when we came up with the
initial data.

We've tested a number of K144XVs now and have found that they are
typically measuring at 1 dB NF, not the 2 dB NF as earlier stated. :-)

73 Eric WA6HHQ

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Bruce Beford-2

Re: K144XV for K3 NF = 1dB

Excellent news!
Looking forward to receiving it.
-Bruce, N1RX

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AB3EN

Re: K144XV for K3 NF = 1dB

In reply to this post by Eric Swartz - WA6HHQ

Thank you! Another quiet over achievement and understatement. Typical no where else but Elecraft!

Dan

Eric Swartz - WA6HHQ, Elecraft wrote

A correction to our initial spec's on the K144XV 2M module for theK3.
There was a miscalculation of its Noise Figure when we came up with the
initial data.

We've tested a number of K144XVs now and have found that they are
typically measuring at 1 dB NF, not the 2 dB NF as earlier stated. :-)

73 Eric WA6HHQ

Dan AB3EN

Jan Holmer SM6TUW

Re: K144XV for K3 NF = 1dB

In reply to this post by Eric Swartz - WA6HHQ

Eric!

Any news on shipping date ?

Jan, SM6TUW
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Eric Swartz - WA6HHQ

Re: K144XV for K3 NF = 1dB

Administrator

See: http://www.elecraft.com/elecraft_shipping_status.htm

We're waiting for all the parts to arrive for production. Its slipped
several weeks and looks like Week 3-4 of Sept.

The W2's are on track for the last week of this month or the first week
of Sept.

73, Eric
----

SM6TUW wrote:
> Any news on shipping date ?
> Jan, SM6TUW
>
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AD6XY

Re: K144XV for K3 NF = 1dB

In reply to this post by Eric Swartz - WA6HHQ

It is nice and low but 1 dB is not exactly cutting edge. I will measure mine when it arrives on some high spec equipment. It does not really matter that mush though on 2m. For terrestrial use the band noise is the limit, for EME anyone serious will be using a low noise pre-amplifier.

What is much more important to operational use and what I would like to know is the dynamic range. Is it over 100 dB at 3kHz spacing like the K3 on HF? What about the intercept point - is it better than 20 dBm? It needs to be here in Europe! There are 4 high power stations active in my grid square, i.e IO91JO and blocking is an issue with the XV144/K3 combo.

Mike

Eric Swartz - WA6HHQ, Elecraft wrote

A correction to our initial spec's on the K144XV 2M module for theK3.
There was a miscalculation of its Noise Figure when we came up with the
initial data.

We've tested a number of K144XVs now and have found that they are
typically measuring at 1 dB NF, not the 2 dB NF as earlier stated. :-)

73 Eric WA6HHQ

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pd0psb

Re: K144XV for K3 NF = 1dB

Slightly OT:
Will the K3/K144XV combo support the European bandplan with 6,25 and 12,5 kHz steps for NFM?

73'
Paul
PD0PSB

What is much more important to operational use and what I would like to know is the dynamic range. Is it over 100 dB at 3kHz spacing like the K3 on HF? What about the intercept point - is it better than 20 dBm? It needs to be here in Europe! There are 4 high power stations active in my grid square, i.e IO91JO and blocking is an issue with the XV144/K3 combo.

Giulio Pico - IW3HVB

Re: K144XV for K3 NF = 1dB

In reply to this post by AD6XY

It isn't exactly true that NF is unimportant on tropo.... otherwise no
one would be using a mast mounted preamplifier.....
The main issue then is preserving the dynamic range, as you pointed out....
On the XV144 module is mandatory to remove the second rx stage to do
that in this case.
The point is, how many stages the new module have? Is the second one (I
assume that it is there) easily removable or bypassable?
About the dynamic range I didn't completely agree with the Elecraft
first choice to use a 50 MHz IF, and the second one with 28 MHz isn't
much better imho.
Ok, I'm a little selfish here, but the serious contesting machines
(Javornik, DB6NT and others) use 14 MHz and there are couple ofgood
reasons to do that.
Usually the HF radios have their better spesc in terms of BDR etc. on
the 20 mt band, and likely the K3 is no different (Wayne, Eric, can you
confirm?).
The image frequency on 28 MHz IF is in the FM broadcasting band (88-108
here), and I must use a cavity filter between the LNA and the RX port of
the xverter, or I get a lot of crackling noise and birdies, as well as
good fm music.
The only real disadvantage in this case (14 MHz IF) is that the band is
somewhat limited by the 14 MHz limits, but for a 144 MHz contester/Dxer,
the portion of band really important is on 500 KHz, from EME to beacon
band 144.000 to 144.500.

These are my two cents on the topic.

73 de Giulio IW3HVB

AD6XY ha scritto:

> It is nice and low but 1 dB is not exactly cutting edge. I will measure mine
> when it arrives on some high spec equipment. It does not really matter that
> mush though on 2m. For terrestrial use the band noise is the limit, for EME
> anyone serious will be using a low noise pre-amplifier.
>
> What is much more important to operational use and what I would like to know
> is the dynamic range. Is it over 100 dB at 3kHz spacing like the K3 on HF?
> What about the intercept point - is it better than 20 dBm? It needs to be
> here in Europe! There are 4 high power stations active in my grid square,
> i.e IO91JO and blocking is an issue with the XV144/K3 combo.
>
> Mike
>
>
>

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Eric Swartz - WA6HHQ

Re: K144XV for K3 NF = 1dB

Administrator

The K144XV module's RX architecture is almost identical to the external
XV144 transverter. Same pre-amp and 2nd stage. Like the XV144, we will
include instructions for removing the 2nd gain stage if you need to for
optimized dynamic range (such as with antenna mounted pre-amps etc.)

We are now only using a 28 MHz IF with two different LO xtal frequencies
to cover the complete 144-148 range, as per Wayne's earlier posting.

73, Eric WA6HHQ

Giulio Pico - IW3HVB wrote:

> It isn't exactly true that NF is unimportant on tropo.... otherwise no
> one would be using a mast mounted preamplifier.....
> The main issue then is preserving the dynamic range, as you pointed out....
> On the XV144 module is mandatory to remove the second rx stage to do
> that in this case.
> The point is, how many stages the new module have? Is the second one (I
> assume that it is there) easily removable or bypassable?
>
> These are my two cents on the topic.
>
> 73 de Giulio IW3HVB
>
>

Alexandr Kobranov

Re: K144XV for K3 NF = 1dB

Let me ask - was +TX signal (9-12V) on centre pin of BNC included in
future plan?
This "option" (one internal jumper at least) is very practical for
most of (in EU :-)) used transverter system control during FD etc.

And thanks for all so big job with Kx, Px, ... development!!

73!
Lexa, ok1dst
K3/10 #727

Eric Swartz - WA6HHQ, Elecraft napsal(a):

> The K144XV module's RX architecture is almost identical to the external
> XV144 transverter. Same pre-amp and 2nd stage. Like the XV144, we will
> include instructions for removing the 2nd gain stage if you need to for
> optimized dynamic range (such as with antenna mounted pre-amps etc.)
>
> We are now only using a 28 MHz IF with two different LO xtal frequencies
> to cover the complete 144-148 range, as per Wayne's earlier posting.
>
> 73, Eric WA6HHQ
>
>
> Giulio Pico - IW3HVB wrote:
>> It isn't exactly true that NF is unimportant on tropo.... otherwise no
>> one would be using a mast mounted preamplifier.....
>> The main issue then is preserving the dynamic range, as you pointed out....
>> On the XV144 module is mandatory to remove the second rx stage to do
>> that in this case.
>> The point is, how many stages the new module have? Is the second one (I
>> assume that it is there) easily removable or bypassable?
>>
>> These are my two cents on the topic.
>>
>> 73 de Giulio IW3HVB
>>
>>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>
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> Please help support this email list: http://www.qsl.net/donate.html
>

Eric Swartz - WA6HHQ

Re: K144XV for K3 NF = 1dB

Administrator

There is a jumper block that optionally allows the connection of a +5V
signal onto the antenna connector during transmit. A maximum of 1 ma.
is available.

73, eric WA6HHQ

Alexandr Kobranov wrote:

> Let me ask - was +TX signal (9-12V) on centre pin of BNC included in
> future plan?
> This "option" (one internal jumper at least) is very practical for
> most of (in EU :-)) used transverter system control during FD etc.
>
> And thanks for all so big job with Kx, Px, ... development!!
>
> 73!
> Lexa, ok1dst
> K3/10 #727
>
>

Alexandr Kobranov

Re: K144XV for K3 NF = 1dB

TNX for info...
So my order for K144XV is to be prepared soon :-)

73!
L. -dst-

Eric Swartz - WA6HHQ, Elecraft napsal(a):

> There is a jumper block that optionally allows the connection of a +5V
> signal onto the antenna connector during transmit. A maximum of 1 ma.
> is available.
>
> 73, eric WA6HHQ
>
> Alexandr Kobranov wrote:
>> Let me ask - was +TX signal (9-12V) on centre pin of BNC included in
>> future plan?
>> This "option" (one internal jumper at least) is very practical for
>> most of (in EU :-)) used transverter system control during FD etc.
>>
>> And thanks for all so big job with Kx, Px, ... development!!
>>
>> 73!
>> Lexa, ok1dst
>> K3/10 #727
>>
>>
>

Alexandr Kobranov

K144XV and +TX signal on BNC?

In reply to this post by Eric Swartz - WA6HHQ

Hello friends,

I tried to look for below mentioned function (jumper settings) in
144MHz module but in last rev of manual I missed or it is not there.
(yet?)

Are there any details about this possibility - to put +TX to centre
pin of BNC output?

Thanks for info,

73!
Lexa, ok1dst
K3/10 #727

Dne 19.8.2009 23:20, Eric Swartz - WA6HHQ, Elecraft napsal(a):