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what is the purpose of a driver amp?

2greedy

Member
Sep 14, 2020
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Hi guy's
What is the purpose of a driver amp? besides the obvious, is it merely so you can drive another amp harder with a lower input transceiver or what is the purpose?
 

Usually it's just what you said. If you had an amp that needs 100 watts peak drive, and your radio only does 18 watts peak, then a small amp between radio and big amp can make up for the difference.

Or you can use the driver to overdrive an amp that doesn't need it. And you can make crazy numbers for a YouTube video.
 
Any time you run an amplifier you will have to "drive it" to make it work. For most smaller amplifiers a radio alone is fine for the driver. Larger amplifiers can be under driven with just a radio or you can add a smaller amplifier as the driver. All depends on what radio you have and how big your amplifier is. Many times us cb'ers tend to overdrive the crap out of amplifiers. Case in point, running say a Texas Star 500v and then adding a Mod V as the driver. A radio will be just fine in that example.
 
For years I have encountered the notion that simply driving a small amplifier harder with more power will make it work better. Someone will name an amplifier that's suitable only for the drive power of a radio alone, and no more. They ask "can I drive it?". My reply is "Yeah, a short drive to the junkyard. Or you can operate it, like with just the radio. Should last a lot longer that way".

Gets the point across all at once.

73
 
Case in point, running say a Texas Star 500v and then adding a Mod V as the driver. A radio will be just fine in that example.

I see this day in and day out on Facebook groups.

' but the 667 has a driver it will be fine'
'My Carl built 1×4 uses 1 2879 to drive 4 2979 your Texas Star can handle it'
' I use a green lizard 250 to drive my TS 500 get 500 watt dead key swing to 750'


All day long.

73
Jeff
 
Not only that but usually you can remove the pad installed in the so called HD amp so it can be drive just fine with a much lower power radio.

The problem today is that idiots buy a radio that put out 45 watts to 100watts and even with the low power dead key turned down modern craptastic non-rf mosfets will swing to their full power or close to it often even with a low dead key.

So they want to drive an amp that really does not need more than 6 watts per bipolar with a radio that is swinging to 45 watts even with a 1-2 watt carrier with the RF turned to minimum. The RF output on a lot of these radio's controls the dead key more than it does the actually limit of the RF power.

But as your original question was about driver amps and that is what they were for. Their was a time when really nicely built radio's arrived doing 3 1/4 watts max and 65% modulation max out of the box.

Then you have those people that want to do hifi, direct inject, asymmetrical modulation at 300% or more modulation. They radio's finals are still limited in output and at 200%+ the carrier has to be turned down to 1/4 watt with forward swing so they daisy chain multiple amps to get the power up high enough usually to drive a commercial tube type am amp.

You also have keydown idiots that need to drive say a 48 transistor amp or larger. You are not dumping 4-12watts into an amp of that size so you will run your radio into a 2 transistor amp driving a 8 transistor amp into into another amp etc.......It goes with out saying all of those amps will be class C and built Manhattan style.
 
Not only that but usually you can remove the pad installed in the so called HD amp so it can be drive just fine with a much lower power radio.

The problem today is that idiots buy a radio that put out 45 watts to 100watts and even with the low power dead key turned down modern craptastic non-rf mosfets will swing to their full power or close to it often even with a low dead key.

So they want to drive an amp that really does not need more than 6 watts per bipolar with a radio that is swinging to 45 watts even with a 1-2 watt carrier with the RF turned to minimum. The RF output on a lot of these radio's controls the dead key more than it does the actually limit of the RF power.

But as your original question was about driver amps and that is what they were for. Their was a time when really nicely built radio's arrived doing 3 1/4 watts max and 65% modulation max out of the box.

Then you have those people that want to do hifi, direct inject, asymmetrical modulation at 300% or more modulation. They radio's finals are still limited in output and at 200%+ the carrier has to be turned down to 1/4 watt with forward swing so they daisy chain multiple amps to get the power up high enough usually to drive a commercial tube type am amp.

You also have keydown idiots that need to drive say a 48 transistor amp or larger. You are not dumping 4-12watts into an amp of that size so you will run your radio into a 2 transistor amp driving a 8 transistor amp into into another amp etc.......It goes with out saying all of those amps will be class C and built Manhattan style.


I want to know what it means to build an amp 'Manhattan style.' I think Dave Made from Jersey (?) is the big name over there.
 
Not only that but usually you can remove the pad installed in the so called HD amp so it can be drive just fine with a much lower power radio.

The problem today is that idiots buy a radio that put out 45 watts to 100watts and even with the low power dead key turned down modern craptastic non-rf mosfets will swing to their full power or close to it often even with a low dead key.

So they want to drive an amp that really does not need more than 6 watts per bipolar with a radio that is swinging to 45 watts even with a 1-2 watt carrier with the RF turned to minimum. The RF output on a lot of these radio's controls the dead key more than it does the actually limit of the RF power.

But as your original question was about driver amps and that is what they were for. Their was a time when really nicely built radio's arrived doing 3 1/4 watts max and 65% modulation max out of the box.

Then you have those people that want to do hifi, direct inject, asymmetrical modulation at 300% or more modulation. They radio's finals are still limited in output and at 200%+ the carrier has to be turned down to 1/4 watt with forward swing so they daisy chain multiple amps to get the power up high enough usually to drive a commercial tube type am amp.

You also have keydown idiots that need to drive say a 48 transistor amp or larger. You are not dumping 4-12watts into an amp of that size so you will run your radio into a 2 transistor amp driving a 8 transistor amp into into another amp etc.......It goes with out saying all of those amps will be class C and built Manhattan style.
:cry::confused::mad:
 
Ok guy's, so if you can drive say a texas star dx500v with 25w, when you use a driver that's say 100w, wouldn't that blow the shit out of the 500 ?
 
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Ok guy's, so if you can drive say a texas star dx500v with 25w, when you use a driver that's say 100w, wouldn't that blow the shit out of the 500 ?

What it will do is smoke the input combiner resistor....at least that's all that happened to mine. I hit my 500v with a KL203, the DEIs held up but the combiner gave up the smoke. Replaced the resistor and she worked fine, then later replaced DEIs with HGs and use it as my 99v2 amp only.
 
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