Alternative transverter IF
|
Colin Smithers
Hi all,
I'm New here. Does anyone know how to set a transverter IF to 28.5MHz, or any other frequency that is not 28,0, 50,0 etc? The incremental oscillator shift only goes so far i think. Reason is I built a 70 MHz transverter from 28.5 as using 28.0 results in a a difficult spurious product. If not I can always continue to subtract .5 in my head as i have done for the last 35+ years :-) (Also sent to the elecraft group) Thanks and 73, Colin G4CWH
|
|
|
|
Ray Maxfield
Colin….. You need to change the Transverter Oscillator Frequency. Most likely a Crystal, or if a Newer DDS Oscillator, the Frequency it is running at. Try to find the Make and model on the internet to get the Data / Information About your Transverter…….. Ray WA6VAB
From: Colin Smithers
Sent: Saturday, May 23, 2020 3:36 PM To: Elecraft-K3@groups.io Subject: [Elecraft-K3] Alternative transverter IF
Hi all,
|
|
|
|
David Ferrington, M0XDF
I could be wrong, but can’t you pick your freq. on the K3?
toggle quoted messageShow quoted text
-73 de M0XDF
On 24 May 2020, at 03:56, Ray Maxfield <wa6vab@...> wrote:
|
|
|
|
Colin Smithers
Hi Ray,
toggle quoted messageShow quoted text
I built the transverter. If you run the LO at 42 MHz then 28.0 is the IF, but there is a bad spurious, its in the math. Which is why I then modified it to 42.5 all those years ago.
I do think the answer lies in altering the K3 internal math, or putting up with having to subtract 500 kHz.
73, Colin
On 24 May 2020, at 03:56, Ray Maxfield via groups.io <wa6vab@...> wrote:
|
|
|
|
Colin Smithers
That is the question! But how? I can only set 28.0, or 50.0. Etc
toggle quoted messageShow quoted text
Its possible I’m missing something obvious. Please have a go and tell me what you find 😊
73, Colin
On 24 May 2020, at 13:50, David Ferrington, M0XDF via groups.io <M0XDF@...> wrote:
|
|
|
|
Alan Baker
I checked the K3 and Cady books and there doesn't appear to be any way of doing what you want. You can set the band, but not a particular offset in the band. Unfortunately the offset provided is only correctional and won't shift far enough for your purpose.
73, Alan. G4GNX
------ Original Message ------
From: "Colin Smithers" <colin@...>
Sent: 23/05/2020 23:15:47
Subject: [Elecraft-K3] Alternative transverter IF Hi all,
|
|
|
|
Colin Smithers
Thanks Alan. That was all I could find too, hence this post.
toggle quoted messageShow quoted text
73, Colin G4CWH
On 25 May 2020, at 00:14, Alan Baker via groups.io <g4gnx@...> wrote:
|
|
|
|
Carl Moreschi
One way to do this is by running my N4PY Pegasus Plus software to control your K3. My software supports up to 5 transverter setups. The IF frequency can be set to anything. This allows the correct frequency to be displayed in the software.
toggle quoted messageShow quoted text
Carl Moreschi N4PY 127 River Moss Way Hertford, NC 27944 www.n4py.com
On 5/25/2020 2:52 AM, Colin Smithers wrote:
Thanks Alan. That was all I could find too, hence this post.
|
|
|
|
Colin Smithers
Thanks Carl, very interesting, I was unaware of your software.
toggle quoted messageShow quoted text
One question: Does the K3 remember that non-standard IF when used stand-alone at a later date - e,g, when out /P? 73, Colin G4CWH
-----Original Message-----
From: Elecraft-K3@groups.io [mailto:Elecraft-K3@groups.io] On Behalf Of Carl Moreschi via groups.io Sent: 25 May 2020 11:42 To: Elecraft-K3@groups.io Subject: Re: [Elecraft-K3] Alternative transverter IF One way to do this is by running my N4PY Pegasus Plus software to control your K3. My software supports up to 5 transverter setups. The IF frequency can be set to anything. This allows the correct frequency to be displayed in the software. Carl Moreschi N4PY 127 River Moss Way Hertford, NC 27944 www.n4py.com On 5/25/2020 2:52 AM, Colin Smithers wrote: Thanks Alan. That was all I could find too, hence this post.
|
|
|
|
Carl Moreschi
No the non-standard IF is just used in my program. Used in this way the K3 is unaware a transverter is being used. The K3 will show 28.xx mhz but my program will show the true transverter frequency. My program also has settings for the transverter drive level. And supports up to 5 different transverters.
toggle quoted messageShow quoted text
Carl Moreschi N4PY 127 River Moss Way Hertford, NC 27944 www.n4py.com
On 5/25/2020 7:37 AM, Colin Smithers wrote:
Thanks Carl, very interesting, I was unaware of your software.
|
|
|
|
Geert Jan de Groot
I can only set 28.0, or 50.0. Etc
Perhaps setting the XVx RF setting one MHz off would work for you. Your transverter IF would then be 29 MHz instead of 28 MHz. I agree that setting the RF settings in steps of 100 kHz would be nice, but I don't see that happen for the K3.
|
|
|
|
Peter G3SMT
Would it not be more expedient to fit a 42MHz crystal to the transverter and solve all the issues that way. 73 Peter G3SMT
On 25/05/2020 00:14, Alan Baker wrote:
|
|
|
|
Geert Jan de Groot
Peter, the TS indicated that using 42 MHz LO gives bad image rejection. Do the math. That's why he is using 41.5 MHz instead.
|
|
|
|
Colin Smithers
Thanks for that thought, Geert. Yes that would work. I was just hoping that there was a front panel entry or utility program solution.
However, so far it doesn’t seem as though there is.
73, Colin
From: Elecraft-K3@groups.io [mailto:Elecraft-K3@groups.io]
On Behalf Of Geert Jan de Groot via groups.io
Sent: 25 May 2020 15:03 To: Elecraft-K3@groups.io Subject: Re: [Elecraft-K3] Alternative transverter IF
I can only set 28.0, or 50.0. Etc Perhaps setting the XVx RF setting one MHz off would work for you. Your transverter IF would then be 29 MHz instead of 28 MHz.
|
|
|
|
Peter G3SMT
Geert, Thank you for the update, I must have missed that post. I use a similar conversion system without any issues although I do not understand how moving 500kHz changes the image rejection. Back to the drawing board. 73 Peter
On 25/05/2020 16:26, Geert Jan de Groot
wrote:
Peter, the TS indicated that using 42 MHz LO gives bad image rejection. Do the math. That's why he is using 41.5 MHz instead.
|
|
|