Bias Is Really Just B(ia)S

[bob85]

A step up from the 2 transistor bias circuit above is the active regulated circuit from motorola that works great for thermal & load regulation,

https://communication-concepts.com/content/AN762/AN762_Application_Note.pdf

 

[kopcicle]

I'm not going to recreate the original post so you'll have to follow the link. I will however offer a small teaser.

First, for you hollow state guys and girls...

Thread 'Hygain Afterburner Plus 482 Grid Bias'

Apr 25, 2018

I'd like to add Grid Bias to my Hygain Amp (using LooseCannon's Schematic) to extend tube life (6JU6's currently) and clean up the signal a bit.
What Bias voltage should I aim for to enable the best result? Tube datasheet shows -55vdc maximum for Grid 1.
Is there any advantage to putting max voltage on the grid? Is a happy medium (maybe -25vdc) better for the result I hope to get?

Any and all suggestions appreciated.

73's
David

• Dmans
• Replies: 38
• Forum: Amplifiers

Post in thread 'mrf 300 ldmos 600 w hf amplifer'

Dec 13, 2024

https://www.aliexpress.us/item/3256806683878670.html?

https://www.aliexpress.us/item/3256807955941409.html?

Amplifier Control Board

https://www.aliexpress.us/item/3256802594892527.html?

Relay Sequencer

and the rest of the candy store

order form

Then our old friends Victor and Yana

List of products

1.8-54 MHz power amplifier completed: NEW! Module HF/6m linear amplifier 2000W…

eb104.ru

But wait,

1000w LDMOS Linear Amplifier 50v 1.8-60Mhz 4 x MHT1803 Pallet

1 KW LDMOS 1.8 - 60MHz power amplifier board fully assembled. The board comes with new devices installed from Digikey onto copper. The boards are made of 2oz copper traces. This amplifier pallet is capable of up to 1KW MAX. Comes fully assemb...

www.vk-amps.com

I'd be looking...

• kopcicle

• 

Thread 'A lack of class, or amplifiers described by class of operation.'

Jan 19, 2022

This was buried in another thread and deserved it's own place.

Amplifier Class Description Conduction Angle
Class-A Full cycle 360o of Conduction θ = 2π
Class-B Half cycle 180o of Conduction θ = π
Class-AB Slightly more than 180o of conduction π < θ < 2π
Class-C Slightly less than 180o of conduction θ < π
Class-D to T ON-OFF non-linear switching θ = 0

Lets get some fundamental myth out of the way .

Solid-state amplifiers cannot be class "AB1" or class "AB2". A bipolar transistor amp cannot be a sub 1 or sub 2 class...

• kopcicle

• 

That gcode is still around somewhere...

NXP

The details are available from NXP for no more than a free account.
It's just numbers.