BY228 Diode--Any Intel?

[David Root]

I just bought some of these at Mouser. $0.85 each, 1500V 3A. Anyone try these in a Dumble build?

Four of them gets a 3000V 6A FW rectifier, bulletproof I think.

[ToneMerc]

David I think using them in series is overkill for a problem that doesn't really exist. However, I have used two UF5407 or UF5408 diodes in series on each side before in a coupe of D builds.

TM

[David Root]

You're probably right TM. I have been using a dual diode TO-220 1200V 8A. I think 1200V is probably cutting it a bit fine spike-wise on 450V B+. They cost less than $1.00.

The data sheet for the BY-228 doesn't indicate any soft recovery capability nor fast recovery in the nanosecond range.

Brandon (Mr. Bludotone) used UF5408-sized diodes in his High Plains Drifter version of the SSS. However they were not marked UF5408, they appear to be marked xxxxG, see pic. Any idea what they are?

I also found the attached article on avalanche diodes, which recommends them for series operation.

[ChrisM]

I agree two in series is probably overkill. I think you would be more than safe with one diode per winding.

Is there pics of his SSS out there btw?

[David Root]

Thanx ChrisM, yes there are other pix but it's gooped. Here's a few. I'm sure I got them here.

[ChrisM]

Thanks Dave!

[Structo]

There are those mysterious coils of wire!

[67plexi]

On Img_2188. Any Ideas on what choke is used looks like Hammond 5-H 150mA

Chime in. Steve.

[David Root]

If it's a Hammond it's had the mfr's label removed. Looks more like a standard Fender 022699 size to me. If so it's at the top of its DC voltage range with plate voltages around 500V. Highest voltage on Fender BF schematics with 022699 is 470 on the Showman IIRC.

[LeftyStrat]

There are those mysterious coils of wire!

Only he used three! He's trying to out-Evil-Amp-Guru us.

[Reeltarded]

I just gooped an amp with nothing but coils. I even built the resistors in situ.. from coils. I used 25 turn pots for the tone pots.

I am a little crosseyed looking at the trannys facing each other like that.. really? Hmm..

[LeftyStrat]

I am a little crosseyed looking at the trannys facing each other like that.. really? Hmm..

Bastards are picking on that little choke...

[JazzGuitarGimp]

The fact that the three coils were intentionally left ungooped leads me to surmise they are decoys.

[JazzGuitarGimp]

I am a little crosseyed looking at the trannys facing each other like that.. really? Hmm..

I was thinking the same thing. After having just been bitten in the arse from NOT using the headphone trick before cutting a chassis for trannies, i am sure having the bells of the PT and OT facing one another will cause hum, at least for my set of trannies. I guess I am going to have to post a new topic, asking if the headphone trick is consistent from one set of trannies to the next...

[martin manning]

I believe Brandon was using custom Heyboer transformers for his ODS, so maybe that's where these came from. Re the orientation, the choke is probably helping to prevent coupling between the PT and OT, and more importantly the axes of the coils may be 90 degrees apart even though the bells are facing eachother. Personally I like to put my DVM on the OT and minimize the mV.