F5 power amplifier

[merlin2069er]

Ok, I'm going to replace R13 (47ohm) resistor.

Can I preform any sort of troubleshooting with the lightbulb on the AC line ?
I can power it up like that - and limit the current (and not smoke anything).

 

[Nelson Pass]

I think so. Just remember that the bias will get a lot
higher without the bulb.

 

[merlin2069er]

What would cause R13 to smoke on me?

Anyone know?

 

[Zen Mod]

poofed mosfet

 

[merlin2069er]

mosfet testing

Testing a MOSFET - YouTube

This is pretty helpful.

 

[labjr]

I think so. Just remember that the bias will get a lot
higher without the bulb.

Aren't they gonna outlaw light bulbs in 2014?

 

[Luke]

Aren't they gonna outlaw light bulbs in 2014?

can you imagine a black market for bulbs to keep pass amps going. NOS GE 100 Watt genuine yellow glow bulb

 

[nar]

can you imagine a black market for bulbs to keep pass amps going. NOS GE 100 Watt genuine yellow glow bulb

Ultra LOL

 

[digits]

Aren't they gonna outlaw light bulbs in 2014?

Those are not lightbulbs, they are light emiting constant current regulators.

 

[ashaw]

if they get that hard to find then you can still use high power resistors. just more expensive.

 

[regiregi22]

Those are not lightbulbs, they are light emiting constant current regulators.

Or just plain transducers

 

[cyclecamper]

They'll still be made in some secret Soviet military base. The US will trade arms for drugs for gold for oil to get light bulbs,

 

[juma]

Testing a MOSFET - YouTube

This is pretty helpful.

Yes, but you need a nine fault battery...

 

[ma_coule]

Yes, but you need a nine fault battery...

(juma, baš si bezobrazan... )

 

[jackinnj]

The F4 has no voltage gain. To reach it's maximum peak voltage output you will need a preamp cappable of about 20Vpk (14Vrms).

OPA552 can swing a lot of voltage with reasonably low distortion. SYN08 used it in one of his HPS pre's.

 

[JonPike]

can you imagine a black market for bulbs to keep pass amps going. NOS GE 100 Watt genuine yellow glow bulb

Worse comes to worse... we could parallel tiny bead thermistors for that negative coefficient.

Someone could build a "Beast with a 1000 Thermistors" amp PCB....

 

[CanAm Man]

[QUOTE

Someone could build a "Beast with a 1000 Thermistors" amp PCB.... [/QUOTE]

Yes. But that design would not be as "brilliant" as one with large incandescent bulbs....!

Don't know if you'all follow the news from U.S. "Capitol Hill". (Come to think of it, who would????). Legislators are apparently lining up to kill that anti-light bulb legislation. (But I will NOT go into politics in the DIY forums!)

 

[h_a]

Legislators are apparently lining up to kill that anti-light bulb legislation.

Would be a pity as technically light bulbs are incredibly inefficient.

I just bought a LED-lamp - amazingly nice light, much nicer than a light bulb and being about equally bright to an 100 W bulb. And that with 12 W only!

Unfortunately still rather expensive, but prices are coming down fast with increasing market volume.

Hannes

 

[regiregi22]

I would go by DIYing my own light bulbs. Take a tungsten wire, an empty jar jam, suck out the air with your mouth, and be prepared to close it pretty fast!!!

 

[digits]

‪Compact Fluorescent verus The Generator‬‏ - YouTube

You want to see that clip if you think that cfl bulbs are efficient.