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QDX-M on 6 meters?

 

Has anyone tried to move the QDX-M to 6-meters? What changes had to be made to the firmware and the LPF? I know the performance may not be perfect but I'm looking to experiment with it. Any help would be appreciated. Many thanks in advance. Jim WB2LHP
 

I too would be interested in the details for QDX 6M.??

TNX!
Bob
WA1EDJ

On Sun, Aug 27, 2023 at 10:47?AM Jim WB2LHP in MI <jmarco1955@...> wrote:
Has anyone tried to move the QDX-M to 6-meters? What changes had to be made to the firmware and the LPF? I know the performance may not be perfect but I'm looking to experiment with it. Any help would be appreciated. Many thanks in advance. Jim WB2LHP

 

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Jim and Bob, and I’m sure others,

I’ve done QDX-Ms for 8m, 8&6m and 6m, I’ll write up all the stuff and post it here. I was considering 4m but I think that’ll be pushing it.?

73
Ross
EX0AA

6

On 28 Aug 2023, at 15:24, WA1EDJ <bobc784@...> wrote:

?
I too would be interested in the details for QDX 6M.??

TNX!
Bob
WA1EDJ

On Sun, Aug 27, 2023 at 10:47?AM Jim WB2LHP in MI <jmarco1955@...> wrote:
Has anyone tried to move the QDX-M to 6-meters? What changes had to be made to the firmware and the LPF? I know the performance may not be perfect but I'm looking to experiment with it. Any help would be appreciated. Many thanks in advance. Jim WB2LHP

 

That would be great Ross...I'm looking forward to building one for 6-meters...Many thanks in advance...Jim WB2LHP
 

TNX Ross!? That would be really helpful.? ?I have an unbuilt QDX R2 that I can build up as an M.? Just leave out the multiband stuff and go for 6M
I'm trying to get on 6M now with a TenTec 1208 transverter and 20M Phaser ( or QDX ).? I'd like?a stand alone 6M rig though.

BTW, do you use any RF gain (preamp) on the 8 or 6M versions?? I'd think sensitivity is lacking at 50MHz and above.

Bob
WA1EDJ
EM83du

On Wed, Aug 30, 2023 at 1:02?AM Afghan Kabulldust via <kabulldust=[email protected]> wrote:
Jim and Bob, and I’m sure others,

I’ve done QDX-Ms for 8m, 8&6m and 6m, I’ll write up all the stuff and post it here. I was considering 4m but I think that’ll be pushing it.?

73
Ross
EX0AA

6

On 28 Aug 2023, at 15:24, WA1EDJ <bobc784@...> wrote:

?
I too would be interested in the details for QDX 6M.??

TNX!
Bob
WA1EDJ

On Sun, Aug 27, 2023 at 10:47?AM Jim WB2LHP in MI <jmarco1955@...> wrote:
Has anyone tried to move the QDX-M to 6-meters? What changes had to be made to the firmware and the LPF? I know the performance may not be perfect but I'm looking to experiment with it. Any help would be appreciated. Many thanks in advance. Jim WB2LHP

 

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?Bob, Jim and others,

Here’s a pic of the 6m prototype. Firstly, I printed my own T50-0 toroids; secondly, you’ll note the T50–6 in the BPF; thirdly, you’ll note the binocular is not the glossy 43 mix rather a BN61-202; and, lastly, the Tx phase splitters is also a T37-61.?
Output transformer is wound for 12V as a Really Weird Twisted Sisters Transformer (search for my previous posts in io).?
Attached:
Design schematic for LPF
Analysis of design.?

Implementation
Pic of prototype?
T50-0 printed toroids
T37-17d can be used:
Input L 10t T37-17
Trap L ? 9t T36-17
BPF L 11t T69-6?
BPF C ?22pF

Measurement:
Rf Filter sweep ?
6m
8m

TinySA both done with 35dB in-line
6m spectrum - quite good.?
8m spectrum the 8m spectrum is borderline


?but after more squeezing/splaying of LPF turns may improve harmonics
 

I missed this topic when it was fresh and now the attachments are missing. Did anyone save these? I'm interested in the details.
?
73 Anders
 

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