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Toroid inductor in sBitx DE upgrade kit

 

I managed to drop one of those two yellow inductors in the process of finally upgrading my rig, and it skittered to places unknown. I would like the specs of it so I can replace it.
 

Shirley,
Those are 1/2 inch toroids, so FT-50
and I believe yellow is mix 43, which is good for LPF in the HF range, so FT-50-43
Can someone confirm this?
Jack, N6LN
 

Yellow toroids are usually powdered iron, not ferrite, and specifically mix #6. The toroids in the upgrade kit are not 1/2 inch; they are smaller; the wire on them makes it hard to get an accurate measurement, but my best guess is that they are 0.3 inches. (I have 0.25 and 0.37 inch toroids in my stock; they're bigger than the T25 and smaller than the T37.

They have 15 turns of wire, at least the one I still can find does :) According to the calculator on , 15 turns on a T30-6 would only be a 0.81 uH inductor, far below the 1.2 uH value that the upgrade instructions say it should?be. A 1.2 uH inductor would need to have 18.3 turns. I suppose I could desolder the one I still have and measure it with my L/C meter to see what its value is.

If the value and my observation of the inductor had matched the values for a T30-6 I would have just gone ahead and wound a couple. (Two because they're used in a push-pull circuit so it's probably best for them to match as closely as possible.) But they don't, which is a reason I asked here; I thought they might be toroids from another source that don't have the same specs as the Micrometals ones. And if they are T30 toroids it will be time for me to put together an order for Diz.

On Wed, Jun 7, 2023 at 7:44?PM John Terrell, N6LN <N6LN@...> wrote:
Shirley,
Those are 1/2 inch toroids, so FT-50
and I believe yellow is mix 43, which is good for LPF in the HF range, so FT-50-43
Can someone confirm this?
Jack, N6LN

 

What you've described sounds like T30-6.? I have extras and can spare a few.
I can send them if you'd like maybe beat your order to Diz...8^)
 

Shirley, which upgrade kit are you referring to? DE upgrade #1 was a power supply fix for the 5V to the Raspberry Pi an upgrade #2 was for a solid state T/R switch. See my photo of the board. I don¡¯t see any toroids of any sort or any color. I was referring to the factory soldered yellow toroids on the main board of the DE that are part of the low pass filter section. Where are your toroids supposed to go?
Jack, N6LN
 

Part of the mod 2 was a change in the bias circuit replacing the resistors with a resistor and inductor in series. I believe that those were T39-6. ?I am away from my shack right now so can not verify.?


73
Evan
AC9TU
 

The PA bias inductors were 15 turns on T30-6 toroids from micrometals.
- f

On Sat, Jun 10, 2023 at 6:33?AM Evan Hand <elhandjr@...> wrote:

Part of the mod 2 was a change in the bias circuit replacing the resistors with a resistor and inductor in series. I believe that those were T39-6.? I am away from my shack right now so can not verify.?


73
Evan
AC9TU
 

Thank you, Ashhar. I need to restock my toroid collection anyway so I will put some of those in the order.


On Fri, Jun 9, 2023, 11:44 PM Ashhar Farhan <farhanbox@...> wrote:
The PA bias inductors were 15 turns on T30-6 toroids from micrometals.
- f

On Sat, Jun 10, 2023 at 6:33?AM Evan Hand <elhandjr@...> wrote:

Part of the mod 2 was a change in the bias circuit replacing the resistors with a resistor and inductor in series. I believe that those were T39-6.? I am away from my shack right now so can not verify.?


73
Evan
AC9TU

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