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Winding quality of tricoils


Gerard
 

Hello,

When I look at different pictures of µBitx, I have the impression that these are not always wound in the same way. Some tricoils appear to be less drawn between the wires.
So I have several questions:
1) Does the quality of the windings affect the reception/emission?
--->Looking at the pictures, the result will be the same for you? (Tricoil1,2,3,4 are picture from µbitx, IMG is picture of my homemade tricoils)

2) At the level of the tricoils, on some parts of the assembly only 2 windings out of three are used. I kept the braided wire I made, so a wrap is present and not used.
--->So should we privilege a tricoil with two windings or we can keep the third that is not used?

cdt


 

Hi Gerard,

I'm not sure it makes a big difference.  I've not measured myself anyway.  However when I wind them myself, I do try to get them a bit neater looking like you do.

I would get rid of the third winding if it is not used.  I think they were just done that way for economy (only one kind of toroid to wind for all the transformers) and not for performance.

More important, look at the Wiki here for the RF power mods and Allison's revisions to the winding of T8, T9, and T10.

73,   Mark


Gerard
 

Evan,
You answered on another subject (pb noise) and put a photo of your µBitx. We can see that the transformers in input and output of the quartz filter have only 2 wires.
At rigor, they seem to be wound side by side.
Maybe mine are too tight
I’m waiting to make a decision to do them again when I get my new antenna
It should take a day to redo

May you take several pictures of all windings to study the case
Thank's

Here your picture


Evan Hand
 

Gerard,
Here are three more pictures of my v5 board:


All of the transformers as supplied by HFSignals are trifilar wound.  Not all windings are used in all locations.  This is on the schematic from HFSignals:
https://www.hfsignals.com/wp-content/uploads/2019/02/ubitx_v5.pdf

That is the case for the input and output of the SSB crystal filter.  You will have to zoom in to see that all are tifilar.

Hope this helps.
73
Evan
AC9TU


Gerard
 

Evan, Thank you for the pictures
I have received this day my new antenna. 
So I installed this one. It’s the same, the reception is very weak.
So much so that I had to stop my tests when the neighbor mowed his grass!! Motor thermic.
Yet, we understand perfectly what is said. You have to put your ear to the speaker.There were Ham who spoke in French clearly on 7MHZ
This proves that the calibration and BFO are well set. We improve even by playing with ATT and RIF.
I will go through the topics with the "weak" keyword. There is reading
Of course, there is a pb in the HF amplification chain. Still, a small question, there is no meaning for a 45MHZ filter.
Mine’s this one, I’m coming from the US on purpose. LOL!
https://www.ebay.fr/itm/Motorola-45MHz-Cristal-de-Bande-Passante-Filtre-Neuf-Qty-2/161791701078?hash=item25ab897056:g:ppkAAMXQ8odRHtxp

Tested at the generator, it was good in bandwidth.
I will continue my research

For the braiding of the coils, this will only play on the impedance.
I put a little reading on you to perfect your French
cdt