A limiter...help!... i need your help...Houston!... i have a problem!

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You can be the one will help me a lot.

The problem:

My daugther use Satelite receiver all day long... she is a teenager... and together the bubble gum she stay all day long in front of the television.... home teather switched on and five speakers pumping loud sound.... i told her the limit...but!...there's a technical problem my television set volume limiters could not face.

When advertising enters, between program parts, breaks.... the volume is increased by the Satelite Systems Television provider in many decibels.... so.... the damn thing start to scream very loud... also the equalization goes to midranges where our ears are sensitive...man!...this bothers a lot!

The solution i am searching for:

Line level amplifier with limiter... transistors, discrete one, not sophisticated, not using Integrated circuits, Field Effect transistors, schmidt triggers, thresholders, companders, compressor or something expensive and Broadcasting quality.... negative about that...i want simple limiter... clipping with diodes, with NFB... will transistor operating as variable resistance into the input, draining signal to ground...well...i want to keep those peaks controled...cutted... held into some maximum presetable...

But please folks...simple...no 15 transistors, many stages with references, comparators, and so on...i need simple, to DIY..dirty thing operated with batteries.... small thing to help me

The one that offer me a good circuit will be called my dear Santa Klaus.

The solution:

A circuit... a sketch...not ideas...something ready to go..,or ready to test..or ready to simulate...or already tested.... simple!

Your attention with me.... please.... loose some minutes to help me folks!



This should work.




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Nice Mitch.... thank you.... can you suggest a transistorized circuit to do this work

Not an integrated circuit, or not using double simetrical supply.

Something even more simple...can you?

I thank you by the nice idea...but i will try, if possible, to avoid chips.... i do not like them..... do not ask me why.... have not empathy to them.

I know the symbol means amplifier stage....so...not a really chip...but chip amps have nice gain and usually are drawed also this way

The symetrical supply makes me think the chip will work better in this way...also the gain controled clipped with the diode.

I would be MORE happy with transistors.... 3 or 4 to each channel and a 9 volts battery feeding energy to them..only one battery.

Of course.... if i could not find a more simple idea...your idea is accepted to try...seems very good...thank you very much my friend.


This works dear Nordic.... two diodes opposite direction...clipping to 0.6 volts

But distorts a lot when operating.... so.... i will be bothered by excess of distortion in the place to be bothered by the increasing of volume.

I hope people can suggest something a little bit better in audio quality result.

thank you dear Nordic.... i am glad you runned to help me dear Nephew.

thank you by your effort into Dx amplifier group buy.



Uncle Charlie


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This one is very good Donk.... i like it..will search for the chip...the main problem

But the circuit matches perfectly.

Hummmm...VHF.... i have worked fixing VHF transceivers man...we are buddies about that...fellow!

73/51 if you are a ham.

thank you very much.

Already searching for more simple diagram...not finding something without the chip and the fet, your suggested unit is the elected for a while.




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I want to do it by myself... i have many parts, good soldering iron, good glasses

and i love to do those things.

To import gods...with prices in dollar is extremelly hard and expensive to my pocket and bureaucraty system.

I want schematic to produce.

Thank you by the informs dear GNI...but the schematic would be much more usefull to me.

I thank you by your kindness to answer me, and by your attention.


CQ 80, CQ80, calling PU1LIY, calling PU1LIY... :)
I was an SWL 80/40/20m band, then I switched to design and produce broadcast transmitters, stereo encoders, etc... for CCIR-VHF band (87,5-108MHz).
I'm happy to hear that there is an other member is into radio too.

LM386 and BF245 devices are easy to find and cheap devices here in the EU. Try asking your parts supplier.

This is a normal use here.... also happens into FM broadcasting..highly compressed...

They compete to be the louder station... sounds awfull that way... i cannot listen broadcasting anymore...hurts my ears.

I have worked into the main brazilian Television Station down the seventies, i am a Television, a broadcasting professional.... i had many figths there...my manager order me to increase level during the advertising breaks.... i used to reduce, because of equalization they already sounded (perception) louder than alive programs or movies.

I was punished twice because of that...i was the Master controller, so... i had the meterings and they had not...so i used to adjust the level using my ears, to make them the same...and they wanted louder for advertising because money was entering the station from the advertiser material...had problems.... and still, now a days, they continue to do the same.

Sony Broadcasting was my last job, i had Brazil North and Northeast as my responsability related all Television Stations on that area...because of that, those things are intimate to me.




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Carlos, my latest project was a VHF amplifier - 40W. Made a prototype, see picture.
I shot the pic with my Fuji - I must say I don't like this photomachine. (Of course quality was much-much better but I reduced it to fit the forum.)


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Yeah... Canon worked better... i had two units..both die because the same defect

Horizontal strips on the image...into the photo only.. into the movie the image still working fine...so.... the CCD suspect is not really the guilty.... circuit start with stripes because programed to behave that way (my personnal suspection about.... i hope i am wrong, because too much dirty thing)

Thank you to show my your Linear VHF amplifier...maybe using a single transistor and another one as class A current driver to the main unit.... a 100 watts unit may be there, screwed from the bottom, crossing the heatsink...the input matching network using plastic variable capacitors and the antena matcher (tuner) network at the output..... very old friends those parts.... they use to smile watching me...we are old friends..those coils and variable capacitors.

Your fuji machine is really not good.....exposition wrong...resolution bad...focus bad too...for sure Canon can eat it into the breakfast..but not for too much long time...as it will burn by itself after 1 year and half or 3500 pictures made.




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Sorry by off topic folks, but camera is a very needed tool to our forum

I could not succeed having so many folks constructing Dx amplifier if i had not posted so many images of it.

Advertising is needed...to offer the image of the product to the consumer (even beeing for free)

This camera is so old as the Canon and had not problems..also used hard.




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