Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: mrhudson27 on June 06, 2022, 12:52:10 pm

Title: Lamp limiter- nada
Post by: mrhudson27 on June 06, 2022, 12:52:10 pm

Hey, all. Another neophyte query: attempted to power up a 90’s Ampeg Reverberocket R50H head that has been stored for > 10 years, fully operational when shelved. Plugged into lamp limiter (homemade, proven track record) and NO light. Not bright, not dim- nothin’. Amp no power up. About to pull chassis & check fuse. I get short vs no short, but what does darkness tell me?

Flogging & belittlement anticipated and welcomed (in a time crunch- haven’t researched threads here yet)

Title: Re: Lamp limiter- nada
Post by: sluckey on June 06, 2022, 01:08:04 pm

Quote from: mrhudson27 on June 06, 2022, 12:52:10 pm

I get short vs no short, but what does darkness tell me?

Darkness tells you that either there is no current flowing (open circuit) or the current is so small that it's not enough to make the bulb filament glow.

Title: Re: Lamp limiter- nada
Post by: kagliostro on June 06, 2022, 01:15:52 pm

A broken fuse ?

Oxidation ?

Broken wire in the Line to Amp path ?

Who can Say

You must practice some further investigation

Franco

Title: Re: Lamp limiter- nada
Post by: Latole on June 07, 2022, 02:52:53 am

Is your bulb lamp is good ?

Your bulb lamp curent limiter; what kind of bulb ? You need a old style incandescent bulb; 75 to 100 watts.

Did it work ( light) on a good working amp ?

After you say yes, check the amp

Title: Re: Lamp limiter- nada
Post by: Keppy on June 07, 2022, 09:34:14 pm

I check my light bulb limiter by plugging a heat gun into it. That draws enough current to get the bulb nice & bright.


Aside from lighting up if there's a short, the limiter doesn't tell you much. It's there to keep you from blowing fuses & circuit breakers. If it doesn't light up, it's time to start checking voltages within the amp.