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KX3-2M module will work well for CW and SSB, even as an I.F. for higher-band XVTRs

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wayne burdick

KX3-2M module will work well for CW and SSB, even as an I.F. for higher-band XVTRs

Administrator

There seems to be some confusion on this point. Once a KX3 has had the extended temperature compensation procedure applied, it will have drift of only about +/- 10 Hz in CW and SSB modes on 2 meters. This is not as good as an oven-controlled oscillator (which there isn't room for, of course), but it should be quite satisfactory for SSB and CW use.

If you use higher-band transverters after the KX3, using 2 meters as an I.F., any drift in external units will add/subtract to the total, not multiply the 2-m drift upwards. (Unless you're using a frequency multiplier -- that's a different story.)

73,
Wayne
N6KR

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Dave-5

Re: KX3-2M module will work well for CW and SSB, even as an I.F. for higher-band XVTRs

So why did a previous reply suggest that it would not be OK for narrowband
use?

Anyone who uses a transverter will know that, as the frequency of the lower
frequency used and the transverter frequency used changes then the
output/input of the chain will change.

The multiplication occurs as the chain of frequencies up to where you want
to get to multiplies and I really do not expect to have to argue this with
RF engineers...

Dave (G0DJA)

----- Original Message -----
From: "Wayne Burdick" <[hidden email]>
To: <[hidden email]>; "Elecraft Reflector" <[hidden email]>
Sent: Tuesday, April 08, 2014 10:37 PM
Subject: [Elecraft] KX3-2M module will work well for CW and SSB,even as an
I.F. for higher-band XVTRs

> There seems to be some confusion on this point. Once a KX3 has had the
> extended temperature compensation procedure applied, it will have drift of
> only about +/- 10 Hz in CW and SSB modes on 2 meters. This is not as good
> as an oven-controlled oscillator (which there isn't room for, of course),
> but it should be quite satisfactory for SSB and CW use.
>
> If you use higher-band transverters after the KX3, using 2 meters as an
> I.F., any drift in external units will add/subtract to the total, not
> multiply the 2-m drift upwards. (Unless you're using a frequency
> multiplier -- that's a different story.)

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wayne burdick

Re: KX3-2M module will work well for CW and SSB, even as an I.F. for higher-band XVTRs

Administrator

Dave,

Are you using a frequency multiplier *applied to the I.F. signal*? If not, then any drift at the I.F., which in the KX3-2M case will be +/- 10 Hz, will simply be *added* to any drift in the final signal.

What I said was that this amount of drift might not be compatible with narrowband data modes. This would also apply to modes like WSPR, unless there's AFC in the algorithm that's tolerant of minor frequency shift. I haven't tried WSPR myself.

Wayne

On Apr 8, 2014, at 4:23 PM, "Dave" <[hidden email]> wrote:

> So why did a previous reply suggest that it would not be OK for narrowband use?
>
> Anyone who uses a transverter will know that, as the frequency of the lower frequency used and the transverter frequency used changes then the output/input of the chain will change.
>
> The multiplication occurs as the chain of frequencies up to where you want to get to multiplies and I really do not expect to have to argue this with RF engineers...
>
> Dave (G0DJA)
>
> ----- Original Message ----- From: "Wayne Burdick" <[hidden email]>
> To: <[hidden email]>; "Elecraft Reflector" <[hidden email]>
> Sent: Tuesday, April 08, 2014 10:37 PM
> Subject: [Elecraft] KX3-2M module will work well for CW and SSB,even as an I.F. for higher-band XVTRs
>
>
>> There seems to be some confusion on this point. Once a KX3 has had the extended temperature compensation procedure applied, it will have drift of only about +/- 10 Hz in CW and SSB modes on 2 meters. This is not as good as an oven-controlled oscillator (which there isn't room for, of course), but it should be quite satisfactory for SSB and CW use.
>>
>> If you use higher-band transverters after the KX3, using 2 meters as an I.F., any drift in external units will add/subtract to the total, not multiply the 2-m drift upwards. (Unless you're using a frequency multiplier -- that's a different story.)
>
>

Jim Brown-10

Re: KX3-2M module will work well for CW and SSB, even as an I.F. for higher-band XVTRs

In reply to this post by Dave-5

On 4/8/2014 4:23 PM, Dave wrote:
> The multiplication occurs as the chain of frequencies up to where you
> want to get to multiplies and I really do not expect to have to argue
> this with RF engineers

Dave,

Are you using (or expect to use) a TRANSVERTER for the UHF bands? That
is, indeed, pretty much the standard way nowadays. In a transverter, the
transceiver input and output are MIXED, not multiplied. So the total
frequency drift is the SUM of the drift of the transceiver (in this
case, the KX3 with 2M transverter) and the drift of the UHF transverter.

Drift of the KX3 with 2M transverter would be multiplied ONLY if you
were to use a system that multiplied the TX output to feed the 1.2 GHz
transmitter. That's feasible, I guess -- 1296 is the 9th harmonic of 144
MHz -- but the 2M rig would need to TX below 144 MHz to cover all of
the band, and the RX would still be MIXED.

73, Jim K9YC
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Dave-5

Re: KX3-2M module will work well for CW and SSB, even as an I.F. for higher-band XVTRs

In reply to this post by wayne burdick

Erm, yes, and yes.

I think that you need to think about what I said that I wanted to use the
KX3-2M for before you try to reply to my complaints that it wont do what I
want it to do.

I'm not using WSPR or any other data modes, other than CW, and that seems to
be where we are getting confused...

Dave (G0DJA)

Dave (G0DJA)
----- Original Message -----
From: "Wayne Burdick" <[hidden email]>
To: "Dave" <[hidden email]>
Cc: <[hidden email]>; "Elecraft Reflector" <[hidden email]>
Sent: Tuesday, April 08, 2014 11:28 PM
Subject: Re: [Elecraft] KX3-2M module will work well for CW and SSB,even as
an I.F. for higher-band XVTRs

Dave,

Are you using a frequency multiplier *applied to the I.F. signal*? If not,
then any drift at the I.F., which in the KX3-2M case will be +/- 10 Hz, will
simply be *added* to any drift in the final signal.

What I said was that this amount of drift might not be compatible with
narrowband data modes. This would also apply to modes like WSPR, unless
there's AFC in the algorithm that's tolerant of minor frequency shift. I
haven't tried WSPR myself.

Wayne

On Apr 8, 2014, at 4:23 PM, "Dave" <[hidden email]> wrote:

> So why did a previous reply suggest that it would not be OK for narrowband
> use?

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wayne burdick

Re: KX3-2M module will work well for CW and SSB, even as an I.F. for higher-band XVTRs

Administrator

If you're using a multiplier of the I.F., then yes, you will need better stability than we can provide within the constraints of the KX3's hardware. I'll add this to the FAQ for the 2-meter module.

If on the other hand you're using mixing to get from 2 meters to the higher bands, the KX3-2M will work just fine for you in CW mode.

73,
Wayne
N6KR

On Apr 8, 2014, at 4:48 PM, "Dave" <[hidden email]> wrote:

> Erm, yes, and yes.
>
> I think that you need to think about what I said that I wanted to use the KX3-2M for before you try to reply to my complaints that it wont do what I want it to do.
>
> I'm not using WSPR or any other data modes, other than CW, and that seems to be where we are getting confused...
>
> Dave (G0DJA)
>
> Dave (G0DJA)
> ----- Original Message ----- From: "Wayne Burdick" <[hidden email]>
> To: "Dave" <[hidden email]>
> Cc: <[hidden email]>; "Elecraft Reflector" <[hidden email]>
> Sent: Tuesday, April 08, 2014 11:28 PM
> Subject: Re: [Elecraft] KX3-2M module will work well for CW and SSB,even as an I.F. for higher-band XVTRs
>
>
> Dave,
>
> Are you using a frequency multiplier *applied to the I.F. signal*? If not, then any drift at the I.F., which in the KX3-2M case will be +/- 10 Hz, will simply be *added* to any drift in the final signal.
>
> What I said was that this amount of drift might not be compatible with narrowband data modes. This would also apply to modes like WSPR, unless there's AFC in the algorithm that's tolerant of minor frequency shift. I haven't tried WSPR myself.
>
> Wayne
>
> On Apr 8, 2014, at 4:23 PM, "Dave" <[hidden email]> wrote:
>
>> So why did a previous reply suggest that it would not be OK for narrowband use?
>