Ekco A33 Surge Limiting Resistor - UK Vintage Radio Repair and Restoration Discussion Forum

Laurdys · 18th May 2009, 8:28 pm

I've just started work on an Ekco A33 (Radiotime) and noticed that there is no surge limiting resistor in series with the valve filaments and wondered whether to fit one to extend the life of the valves

.
Do you think this would be a wise move?

Maplins part number: N96BT
This one is good up to 18 amps.

Silicon · 19th May 2009, 1:18 am

The initial resistance of the inrush current limiter when cold is only 2 Ohms.
Its effect will probably be small.
I have used one between the rectifier and reservoir capacitors on a transistorised power amp supply and it did reduce the surge.
The house lights used to flicker when I turned the amp on!

PJL · 19th May 2009, 7:34 am

The inrush current for an AC valve radio that is not fitted with a suppression capacitor will not be very great anyhow.

Laurdys · 19th May 2009, 5:36 pm

thanks for the advice i think i will leave it as it is then

this thread can be closed

18th May 2009, 8:28 pm	#1
Laurdys Pentode Join Date: May 2009 Location: Stockton-on-Tees, County Durham, UK. Posts: 154	Ekco A33 Surge Limiting Resistor I've just started work on an Ekco A33 (Radiotime) and noticed that there is no surge limiting resistor in series with the valve filaments and wondered whether to fit one to extend the life of the valves . Do you think this would be a wise move? Maplins part number: N96BT This one is good up to 18 amps.

19th May 2009, 1:18 am	#2
Silicon Nonode Join Date: Jun 2007 Location: Coulsdon, London, UK. Posts: 2,169	Re: Ekco A33 Surge Limiting Resistor The initial resistance of the inrush current limiter when cold is only 2 Ohms. Its effect will probably be small. I have used one between the rectifier and reservoir capacitors on a transistorised power amp supply and it did reduce the surge. The house lights used to flicker when I turned the amp on!

19th May 2009, 7:34 am	#3
PJL Dekatron Join Date: Sep 2005 Location: Seaford, East Sussex, UK. Posts: 5,997	Re: Ekco A33 Surge Limiting Resistor The inrush current for an AC valve radio that is not fitted with a suppression capacitor will not be very great anyhow.

19th May 2009, 5:36 pm	#4
Laurdys Pentode Join Date: May 2009 Location: Stockton-on-Tees, County Durham, UK. Posts: 154	Re: Ekco A33 Surge Limiting Resistor thanks for the advice i think i will leave it as it is then this thread can be closed