2 (tr)uSDX Assembly

After Assembly, you need to install Firmware

Klick here to get to the Group Buy Instructions

Here are the Results of the Harmonic measurements:

80m
60m
40m
30m
20m

The TRX was un-tweaked, and built completely according to the Schematic Values of Capacitors and Toroids. Harmonic suppression is better than -43dB on ALL Bands.

UPDATE: 16. March 2022:

Alternative Bands Setups

We´ve got many user requests for alternative Band Setup. Personally we´re not really interested in that and lack the time to double- and triple check all the Information, but we wanted to give you -the user- the possibility to play around with it. Since (tr)uSDX is supposed to be a standardized rig, we cannot allow for totally custom Band Selection, but we´ve prepared 3 Options in Firmware for you:

Band-Slot AssignmentK1K2K3K4K5
Lo (current Standard)20m30m40m60m80m
Hi (Only Hi Bands)10m12m15m17m20m
Classic (Classical Bands w/o WARC)10m15m20m40m80m
Can be selected at in Menu 8.7 “Band Config”

UPDATE 08. May 2022:

Here are my Results with “Classic Bands” Setup, using the FDT 86256 FET: (Again UPDATED 20 May 2022)

Because of higher gate threshold value, this FET requires higher PA BIAS Max Setting of 160 for best performance. With PA Bias Max 160 it was possible to get at or above 80% up to 10m Band, even with Red Toroids.
I was using the Toroids and PCB provided by our official Supplier Sunny.

END Update

IMPORTANT !

The below Tables represent UNTESTED Component Values ! Use them with caution at your own Risk. The Values need to be tweaked for 5W@12V and Efficienct over 80%. Please report back in the forum about the Values that actually made it happen for you.

ATTENTION: This Table are THEORETICAL Values for 1x FDT86256 (Install ONLY Q5 as PA FET)

Band80m60m40m30m20m17m15m12m10m
F (MHz)3,605,357,1010,1014,1518,0821,1024,9028,10
CX0//CX11041697523364257199169142125
CX2//CX3276518601402985703550472400354
LX11,340,900,680,480,340,270,230,190,17
CX4//CX5221214881121788563440377320283
CX8//CX9221214881121788563440377320283
LX20,660,450,340,240,170,130,110,100,09
CX6//CX773749637426318814712610794
This Table is for 1x FDT86256 (All Inductances in µH – All Caps in pF)

ATTENTION: This Table are THEORETICAL Values for 3x BS170 (Install ONLY Q1,Q2 and Q3 as PA FET)

Band80m60m40m30m20m17m15m12m10m
F (MHz)3,565,357,0510,114,0518,0821,0524,928,05
CX0//CX165742030719912888695039
CX2//CX318641240941657472367315266237
LX12,041,361,030,720,520,40,350,290,26
CX4//CX518261215922644463360309261232
CX8//CX918261215922644463360309261232
LX20,820,550,410,290,210,160,140,120,1
CX6//CX76094053072151541201038777
This Table is for 3xBS170 (All Inductances in µH – All Caps in pF)

Depending on your Setup, you only need to place the desired Component-Values to the Right Band-Slots together with the FET you want to use and Activate it in Firmware.

FAQ:

CX0//CX1 ????

X Stands for Band slot (e.G. 1 for K1 -> so this would be then C10//C11)

“//” means: Those 2 are in Parallel. Putting Capacitors in Parallel is a simple Addition of Capacitance

Example:

CX0//CX1 for FDT86256 and 80m is supposed to be 1041pF

So we need to find 2 (available) Capacitor-Values, that will result in a total Capacitance closest to 1041pF as possible.

470pF//560pF would be close = 1030pF

620pF//430pF would be close = 1050pF

680pF//360pF -> BINGO = 1040pF

but a lot of other combinations are possible. Just use what you can get or have available and try to get as close as possible.

There might also be cases where you can achieve it with just one Cap. In this case place it to one of the 2 available Cap-Footprints and leave the other one empty.

Remember: (tr)uSDX Filter Capacitors ALWAYS need to be C0G/NP0 Types, rated for at least 100V !

Use some online or offline tool, to calculate the amount of Windings for your Toroids. I like this one: https://www.dl0hst.de/mini-ringkern-rechner.htm#en

Depending on Frequency you can use either T37-2 (Red) or T37-6 (Yellow) Toroids.

Happy tuning !