开云体育

ctrl + shift + ? for shortcuts
© 2025 开云体育
  1. BITX20
  2. Topics

Bitx ver 3b/3c Linear power supply 40 meters

 

Near the bottom of the pcb is a .55uh inductor, I don't have one and went on Toroid King site and claims T50-2 9 turns. My E-bay meter shows it as a resistor. Should I just go with the t50-2? 9 turns?
 


Which BITX pcb are you referring to? I think you were working with the v3.B from Sunil.
What is the reference designator?


john
AD5YE


---In BITX20@..., <ka2rrz@...> wrote :

Near the bottom of the pcb is a .55uh inductor, I don't have one and went on Toroid King site and claims T50-2 9 turns. My E-bay meter shows it as a resistor. Should I just go with the t50-2? 9 turns?
 

Yes vers 3b /3c power supply pcb he small one with the irf520


On Wednesday, January 11, 2017 4:34 PM, "iam74@... [BITX20]" wrote:


?

Which BITX pcb are you referring to? I think you were working with the v3.B from Sunil.
What is the reference designator?


john
AD5YE


---In BITX20@..., wrote :

Near the bottom of the pcb is a .55uh inductor, I don't have one and went on Toroid King site and claims T50-2 9 turns. My E-bay meter shows it as a resistor. Should I just go with the t50-2? 9 turns?
 

I have no idea what this "E-bay meter" thingie is.
Regardless, even if it was supposed to accurately measure an inductance that's down in the nano-Henry's, I'd have a lot more faith in the torroid charts.

Here's a chart that says 0.55uH would be more like 11 turns on a T50-2:
? ??
??
Jerry, KE7ER
?

---In BITX20@..., <ka2rrz@...> wrote :

Near the bottom of the pcb is a .55uh inductor, I don't have one and went on Toroid King site and claims T50-2 9 turns. My E-bay meter shows it as a resistor. Should I just go with the t50-2? 9 turns?
 

ok thank you. I guess I am the only builder of this like the Bingo pcb I got last year? anyhow this was reassuring.


On Wednesday, January 11, 2017 6:49 PM, "jgaffke@... [BITX20]" wrote:


?
I have no idea what this "E-bay meter" thingie is.
Regardless, even if it was supposed to accurately measure an inductance that's down in the nano-Henry's, I'd have a lot more faith in the torroid charts.

Here's a chart that says 0.55uH would be more like 11 turns on a T50-2:
? ??
??
Jerry, KE7ER
?

---In BITX20@..., wrote :
Near the bottom of the pcb is a .55uh inductor, I don't have one and went on Toroid King site and claims T50-2 9 turns. My E-bay meter shows it as a resistor. Should I just go with the t50-2? 9 turns?
 

This is L2. Yes, it is a toroid wound coil.

It is referred to on p.8 of the BITX v.3B complete assembly manual. It is part of a Pi network feeding the gate of the IRF510 to better balance the impedance needs. This is seen in the schematic of the PA. The original idea came form Farhan in a new design for a power amplifier, which is also in the files section.


john
AD5YE


---In BITX20@..., <ka2rrz@...> wrote :

Yes vers 3b /3c power supply pcb he small one with the irf520


On Wednesday, January 11, 2017 4:34 PM, "iam74@... [BITX20]" <BITX20@...> wrote:

Which BITX pcb are you referring to? I think you were working with the v3.B from Sunil.
What is the reference designator?


john
AD5YE
 

From the version 3 manual "L3 and L4 will take 8" of wire and should measure .55uh.
Wind 13 turns on a T37-6 core. Be sure to spread out the turns over the whole core. If they bunch together, it will raise the inductance."

Pictures and instructions at

There are some minor changes for the newer boards but it should help you answer any questions.

Leonard

?

1 - 7 of 7