5f1 first build

[statorvane]

The smoothing in Merlin's s article concerns smoothing the DC voltage of the power rail - "downstream" of the rectifier. C12 through C15 are snubbers for the diodes in the rectifier. If you use UF4007 you can eliminate them. C1 and C2 I am not sure. I think C1 may reduce or eliminate a "pop" when switching on the power. C2 may be for the same thing.

General question for the forum, isn't C1 referred to as the "death cap"? I seem to remember this when I build a 5F6-A, and left it out.

[Mikante]

Thank you, i get it now, smoothing and voltage drop are two different things.
You said C1 and C2 are probably there to eliminate the pop when switching on and off, are you referring to C11 and C16 as they are listed in 600 champ schematic?

[statorvane]

Yes, C11 and C16 - sorry for the confusion - where C11 may be a "Death Cap".

[ChopSauce]

Hello,
I m already following your advice, it is simplier for me to upgrade the 600 champ to a point to point type of circuit, using both transformers, switch and lamp, along with the rectifier circuit.
8443EA5F-2921-4357-BCD5-9F5D3B6E5C29.png
I have just read the file about the “smoothing” that you provided with the link.
I m just a little confused now. In the the schematic above you can see there is a 0.1 250v cap on the primary and a 0.1 600v cap on the secondary right before the rectifier bridge and without a resistor in parallel, so i guess this was not meant for smoothing. Is this meant just as a voltage drop?

My bad. I've taken shortcuts. It is the resistor of the (R, C) cell, which drops some voltage. By inserting one more (R,C) before the first node - the plus pole of C6 - you have both benefits of a lower voltage and increased filtering. I am no circuit designer but I think (1k, 33-47uF) would be common value. Not sure how much that lowers B+, though.

[Mikante]

Yes, C11 and C16 - sorry for the confusion - where C11 may be a "Death Cap".

No problem, i m a newbie and i need to ask twice on anything, i can easily get lost otherwise

Hello,
I m already following your advice, it is simplier for me to upgrade the 600 champ to a point to point type of circuit, using both transformers, switch and lamp, along with the rectifier circuit.
8443EA5F-2921-4357-BCD5-9F5D3B6E5C29.png
I have just read the file about the “smoothing” that you provided with the link.
I m just a little confused now. In the the schematic above you can see there is a 0.1 250v cap on the primary and a 0.1 600v cap on the secondary right before the rectifier bridge and without a resistor in parallel, so i guess this was not meant for smoothing. Is this meant just as a voltage drop?

My bad. I've taken shortcuts. It is the resistor of the (R, C) cell, which drops some voltage. By inserting one more (R,C) before the first node - the plus pole of C6 - you have both benefits of a lower voltage and increased filtering. I am no circuit designer but I think (1k, 33-47uF) would be common value. Not sure how much that lowers B+, though.

As i just said, it is easy form me to get confused. But i got to thank you guys, i m learning a lot.

[martin manning]

Yes, C11 and C16 - sorry for the confusion - where C11 may be a "Death Cap".

The Death cap was connected from one side or the other of the AC mains to ground via a switch. C11 and C16 are cross-line filters.

[martin manning]

@Martin how would you add a rc filter?

Like this. The additional filter stage will reduce 120 Hz hum in the speaker by reducing the ripple voltage going into the output transformer. Adjust the size of the resistor to get the B+ voltage you want. Since the total current is around 40 mA, you will get ~40V drop using a 1k resistor.

Also attached is another schematic you might find useful, the reissue '57 Champ, which has voltages marked at a number of points in the circuit.

[Mikante]

Thank you very much, i will add this extra filter stage after i can check the circuit withkut it and understand what kind of voltage drop i need.