You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
The Feb 2025 Radioddity Giveaway Results are In! Click Here to see who won!

Reply to thread

Message

JesseJamesDallas,
The 300A is not built with a current surge resistor (normally 3.9 - 10 ohms @ 5W) or a current surge choke (1 - 10 mH) in series with rectifier string, but that is what these components are supposed to do-protect the rectifiers. {The Skipper 300 has a "glitch" resistor in each leg of the transformer secondary. They are .5 ohms @ 10 watts} Although a definite pain, due to space constraints, it was for this reason that I replaced every diode in mine. All spike suppressing diodes on relay coils, 12v rectifier diodes and negative grid control diodes. And since it required removing all 4 circuit boards, I replaced all the resistors(small and large wattage) and electrolytic capacitors.

I have used the 1N5408 diodes in 5 recent amplifier refurbs without an issue (I have 3 more amps to do and am planning on using 1N5408 on those as well) . They are rated at 1000v and 3 amps. The original diodes in my 300A were 1N5406 rated at 600v and 3 amps.

It could be that another component is contributing to excess current through the rectifiers?? A filter capacitor comes to mind.

I am sure someone with much more experience than me can offer a suggestion for this issue.

Good Luck!

73's
David

<blockquote data-quote="Dmans" data-source="post: 662611" data-attributes="member: 49046">JesseJamesDallas,The 300A is not built with a current surge resistor (normally 3.9 - 10 ohms @ 5W) or a current surge choke (1 - 10 mH) in series with rectifier string, but that is what these components are supposed to do-protect the rectifiers. {The Skipper 300 has a &quot;glitch&quot; resistor in each leg of the transformer secondary. They are .5 ohms @ 10 watts} Although a definite pain, due to space constraints, it was for this reason that I replaced every diode in mine. All spike suppressing diodes on relay coils, 12v rectifier diodes and negative grid control diodes. And since it required removing all 4 circuit boards, I replaced all the resistors(small and large wattage) and electrolytic capacitors.I have used the 1N5408 diodes in 5 recent amplifier refurbs without an issue (I have 3 more amps to do and am planning on using 1N5408 on those as well) . They are rated at 1000v and 3 amps. The original diodes in my 300A were 1N5406 rated at 600v and 3 amps.It could be that another component is contributing to excess current through the rectifiers?? A filter capacitor comes to mind.I am sure someone with much more experience than me can offer a suggestion for this issue.Good Luck!73&#039;sDavid</blockquote>

[QUOTE="Dmans, post: 662611, member: 49046"] JesseJamesDallas, The 300A is not built with a current surge resistor (normally 3.9 - 10 ohms @ 5W) or a current surge choke (1 - 10 mH) in series with rectifier string, but that is what these components are supposed to do-protect the rectifiers. {The Skipper 300 has a "glitch" resistor in each leg of the transformer secondary. They are .5 ohms @ 10 watts} Although a definite pain, due to space constraints, it was for this reason that I replaced every diode in mine. All spike suppressing diodes on relay coils, 12v rectifier diodes and negative grid control diodes. And since it required removing all 4 circuit boards, I replaced all the resistors(small and large wattage) and electrolytic capacitors. I have used the 1N5408 diodes in 5 recent amplifier refurbs without an issue (I have 3 more amps to do and am planning on using 1N5408 on those as well) . They are rated at 1000v and 3 amps. The original diodes in my 300A were 1N5406 rated at 600v and 3 amps. It could be that another component is contributing to excess current through the rectifiers?? A filter capacitor comes to mind. I am sure someone with much more experience than me can offer a suggestion for this issue. Good Luck! 73's David [/QUOTE]

Top Bottom