VFE Bumblebee

[jimilee]

Here's the breakdown. I wanted to support Peter Rutter, so I paid the 10.00 to get his files. Even though I could get a Bumblebee board from Brian, I paid 22 for 3, I don't know why. The fix was in the 5457, the trick is the calibration.








Sent from my iPhone using Tapatalk

[cooder]

Super cool Jimi, great graphics! Has a sting to it... 

[alanp]

That is a busy, busy board.

[benny_profane]

Glad to see you got it sorted out! Where'd you end up getting the JFET that worked for you?

[jimilee]

Glad to see you got it sorted out! Where'd you end up getting the JFET that worked for you?

Ended up getting it from someone here. Your best bet is just to go on eBay and buy a bunch (now than 5) from someone in the states.


Sent from my iPhone using Tapatalk

[benny_profane]

Glad to see you got it sorted out! Where'd you end up getting the JFET that worked for you?

Ended up getting it from someone here. Your best bet is just to go on eBay and buy a bunch (now than 5) from someone in the states.


Sent from my iPhone using Tapatalk

Good advice. I'm set with TH JFETs for a while and have been moving toward SMD JFETs anyway...I was curious because that seemed to be the sticking point in your troubleshooting thread.

[jimilee]

Glad to see you got it sorted out! Where'd you end up getting the JFET that worked for you?

Ended up getting it from someone here. Your best bet is just to go on eBay and buy a bunch (now than 5) from someone in the states.


Sent from my iPhone using Tapatalk

Good advice. I'm set with TH JFETs for a while and have been moving toward SMD JFETs anyway...I was curious because that seemed to be the sticking point in your troubleshooting thread.

Yessir. Do the 5457 smt jfets vary in hfe? I know in the 201s, they tend to be pretty steady and kind of high.


Sent from my iPhone using Tapatalk

[benny_profane]

Data sheets and the analysis in the link below  have all the info you need.

http://runoffgroove.com/fetzervalve.html

I've found that the SMD parts are generally more consistent. The specs are the same as the TO-92 devices, but they are still in production and haven't been sorted through already.

[jimilee]

Data sheets and the analysis in the link below  have all the info you need.

http://runoffgroove.com/fetzervalve.html

I've found that the SMD parts are generally more consistent. The specs are the same as the TO-92 devices, but they are still in production and haven't been sorted through already.

Very cool. If I can get them in various Hfe then I am going to grab 20 or so.


Sent from my iPhone using Tapatalk

[pierre67]

Very nice buil !
...is it possible that you have the optocupler reversed?

[jimilee]

Very nice buil !
...is it possible that you have the optocupler reversed?

Nope, any other way and the two trannies above it get the wrong voltages. The dot is where it's supposed to be.


Sent from my iPhone using Tapatalk

[Cybercow]

JimiLee - so glad you finally got it working. Looks great!

[jimilee]

JimiLee - so glad you finally got it working. Looks great!

Thank you. You gotta have the right 5457. It was affecting the voltage and I dont'know why. It was a bear, that's for sure.

[Cybercow]

JimiLee - so glad you finally got it working. Looks great!

Thank you. You gotta have the right 5457. It was affecting the voltage and I dont'know why. It was a bear, that's for sure.

JimiLee - FETs are a fickle device. Kinda like NOS germanium trannies in that the specs can be all over the map for any given part number. When ever applying FETs, I always socket them because it can be a crap shoot selecting them. Even with a Peak Atlas DCA75 to pre-test (measure) them, they can be fickle. Still, happy to see this done.

How do you like it? Is the swell dramatic or  . . . . . ??

[danfrank]

Jimilee you're killing me here! What's the correct specs for the 5457?!? What the build doc says??
Lol