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6m stuff

 

Roberto et al,

Here¡¯s my design for a 6m QDX-M and some of the test results. I only have a TinySA to check the spectrum but it¡¯s pretty close to Hans¡¯ up-market Spectrometer.
You¡¯ll see BPF is 11t on a T50-6 and the cap is 22pF.
RF sweep and image sweep from built in test.
Elsie circuit and plots, you¡¯ll note the number of turns on T37-17s.

I hope that helps.

73
Ross




























Sent from my iPhone 6
 

Of course caps a combos of standard values in LPF 33+30 =63pF and 82+22+22 =226pF

73
Ross

Sent from my iPhone 6

On 22 Sep 2023, at 15:00, Afghan Kabulldust via groups.io <kabulldust@...> wrote:

?Roberto et al,

Here¡¯s my design for a 6m QDX-M and some of the test results. I only have a TinySA to check the spectrum but it¡¯s pretty close to Hans¡¯ up-market Spectrometer.
You¡¯ll see BPF is 11t on a T50-6 and the cap is 22pF.
RF sweep and image sweep from built in test.
Elsie circuit and plots, you¡¯ll note the number of turns on T37-17s.

I hope that helps.

73
Ross




























Sent from my iPhone 6





<IMG_9371.jpg>
<IMG_9443.JPG>
<IMG_9444.JPG>
<IMG_9537.JPG>
<IMG_9543.jpg>
<IMG_9611.jpg>
<IMG_9770.JPG>
<IMG_9771.JPG>
 

?Of course caps a combos of standard values in LPF 33+30 =63pF and 82+22+22 =226pF er 126pF (fat fingers on iPhone)

73
Ross

Sent from my iPhone 6


On 22 Sep 2023, at 15:00, Afghan Kabulldust via groups.io <kabulldust@...> wrote:

?Roberto et al,

Here¡¯s my design for a 6m QDX-M and some of the test results. I only have a TinySA to check the spectrum but it¡¯s pretty close to Hans¡¯ up-market Spectrometer.
You¡¯ll see BPF is 11t on a T50-6 and the cap is 22pF.
RF sweep and image sweep from built in test.
Elsie circuit and plots, you¡¯ll note the number of turns on T37-17s.

I hope that helps.

73
Ross




























Sent from my iPhone 6





<IMG_9371.jpg>
<IMG_9443.JPG>
<IMG_9444.JPG>
<IMG_9537.JPG>
<IMG_9543.jpg>
<IMG_9611.jpg>
<IMG_9770.JPG>
<IMG_9771.JPG>
 

Thanks Ross, that was a quick reply.
I wonder if anyone who inquired about the topic can find it here.
Unfortunately, they use the forum as a messenger, instead of entering what they are interested in into the search engine.
--
Gyula HA3HZ
 

On 22/09/2023 16:03, HA3HZ wrote:
I wonder if anyone who inquired about the topic can find it here
I looked, unfortunately the attachments are gone.
After 100MB of attachments old ones get deleted.
Old messages are not always useful.
Good information needs to be saved elsewhere.

73 Alan G4ZFQ
 

Thanks Alan. I faced the same issue, but was thinking was my fault.?
100 MB is a reasonable limit, considering the traffic we are able to produce :-)

Roberto

--
I2RWR
Roberto Ranzani - JN45mn
 

Lots there, I kept this one


-------- Forwarded Message --------
Subject: [QRPLabs] 6m stuff
Date: Fri, 22 Sep 2023 14:59:49 +0000
From: Afghan Kabulldust via groups.io <kabulldust@...>
Reply-To: [email protected]
To: [email protected]

Roberto et al,

Here¡¯s my design for a 6m QDX-M and some of the test results. I only have a TinySA to check the spectrum but it¡¯s pretty close to Hans¡¯ up-market Spectrometer. You¡¯ll see BPF is 11t on a T50-6 and the cap is 22pF. RF sweep and image sweep from built in test. Elsie circuit and plots, you¡¯ll note the number of turns on T37-17s.
I hope that helps.
73
Ross




























Sent from my iPhone 6
 

Hi everyone. I am interested in in using a new QDX-M PCB Rev5M for 6m and have been following messages about BPF and LPF values - no problem. What I am asking about is the link settings on the PCB which apparently set the values shown in PUTTY for 10/11/12m. Is it possible to program in entirely new settings for 6m in the terminal app? If so do I use the links on the pcb or not? I wonder what happens if I don't set either of the links?
?
73 Chris G0IMX?
 

I think if you don't set any links it doesn't "know" it's a QDX-M and will leave several bands in the terminal.
As far as setting whatever band parameters you want, I don't know if the links override that on a single band version....I have the same question.. if I set links for 10m, can I then change the band settings in Putty, or will it revert to 10m every time I cycle power?
?
-Nate
N8BTR
 

Hi Chris, Nate

I do need to (when I am finished QMX SSB!) go back to QDX-M and finish the original intention: making the band configuration jumpers work for all bands 2200m to 6m, and testing/documenting the filter values?for those.?

Meanwhile: if you manually edit the settings, it is not going to go back to 10m every time you cycle power. So the jumper link settings are used to initially set up the band from some suitable defaults; but that only happens once (well to be accurate, it happens each time you change the band setting jumpers). So if you set the wires for 10m and then?manually edit it to 6m, that will work fine.?

73 Hans G0UPL



On Thu, Nov 7, 2024 at 1:45?PM natereik via <natereik=[email protected]> wrote:
I think if you don't set any links it doesn't "know" it's a QDX-M and will leave several bands in the terminal.
As far as setting whatever band parameters you want, I don't know if the links override that on a single band version....I have the same question.. if I set links for 10m, can I then change the band settings in Putty, or will it revert to 10m every time I cycle power?
?
-Nate
N8BTR
 

Thanks Hans. That's great news. I can't play with the QDX-M as it's a Christmas present so I'm just looking at the experiment from all angles!
?
73 Chris G0IMX
 

Thanks for that confirmation, Hans!
While I don't have a spectrum analyzer, I'll report my findings and stats here for a 160m build. It may be a data point for your future use, when you get to filling out QDX-M filters, etc. I plan to use the QMX+ values as a starting point, but am going to try with T50-2 toroids, I think.?
?
-Nate?
N8BTR
 

If this means a new QDX board, I'd recommend adding the integrator type wave shaping scheme described on page 6.64 of EMRFD, fig 6.114-E
The KD1JV Mountain Topper has integrator type keying giving a nice symetrical trapezoid using a PFET with cap from drain to gate for feedback.
There's also an optional zener diode in there to make rise and fall rates identical.
?
That was developed in the old Yahoo AT_Sprint forum back in 2007 for the ATS3A.
Search for "Message: 1080 " in the following archive to see the rather long discussion:
I had no idea then that it was a decades old technique.
?
Jerry, KE7ER
?
?
On Thu, Nov 7, 2024 at 03:37 AM, Hans Summers wrote:

I do need to (when I am finished QMX SSB!) go back to QDX-M and finish the original intention: making the band configuration jumpers work for all bands 2200m to 6m, and testing/documenting the filter values?for those.?
 

Ah, you do have integrator type key shaping on the QCX.
?
On Thu, Nov 7, 2024 at 08:20 AM, Jerry Gaffke wrote:

If this means a new QDX board, I'd recommend adding the integrator type wave shaping scheme described on page 6.64 of EMRFD, fig 6.114-E
 

I have done what Han's describes in the terminal settings and my QDX-M 6M works fine.
I did change some of the inductors per a few suggestions on this list (Ross ?) and all works well.
I've made a few FT8 Q's from EM83du during Es openings.
3W out on 6M.? Not bad.? So, it does work!? I'd have to dig the real details out if really interested.

Bob
WA1EDJ

On Thu, Nov 7, 2024 at 5:03?AM G0IMX via <clacey=[email protected]> wrote:
Hi everyone. I am interested in in using a new QDX-M PCB Rev5M for 6m and have been following messages about BPF and LPF values - no problem. What I am asking about is the link settings on the PCB which apparently set the values shown in PUTTY for 10/11/12m. Is it possible to program in entirely new settings for 6m in the terminal app? If so do I use the links on the pcb or not? I wonder what happens if I don't set either of the links?
?
73 Chris G0IMX?

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