Palamor HD 2x 1446

[Ziploc]

Morning, before I buy will this amp work with a comp cobra 29? My radio has variable power and peak swing to about 40 watts. Thanks dk on radio is 0 to about 18 bird.

 

[Big Kahuna]

Even if it says HD you don’t want to run a bunch into it, keep deadkey 2W or under, peak 15W. I’d shoot for around 130-150 watt output peak and wouldn’t push harder than that. If you need more watts look for a 2 x 2879 amp or straight 4 transistor amp.

 

[Ziploc]

So my comp 29 pep is 40+. Were to set my radio variable ?

 

[2NC995]

I agree with Big Kahuna on this, except that I'd be willing to push it slightly harder than 150 peak. I think it will comfortably do 180-200 watts. 1446s are pretty rugged transistors. I've abused them very hard at times and had no issues (even though you could cook breakfast on the amp).

Anyway, 40 watts peak input is too much, IMO. Big Kahuna's recommendation of 15 watts is much more realistic. I also agree that a low dead key will be needed. 2 watts or less, I would guess,

The "HD" used in CB amplifier naming is generally meaningless, IMO.

 

[Shadetree Mechanic]

The 40+ watts is too much to put into it. Dead key will probably need to be what ever the lowest will key the amp. Maybe 1/2 a watt.

 

[Ziploc]

Thank you

 

[543_Dallas]

Morning, before I buy will this amp work with a comp cobra 29? My radio has variable power and peak swing to about 40 watts. Thanks dk on radio is 0 to about 18 bird.

Kind of off topic but who tuned the radio and what final does it have? I've saw some hot ones but 18 bird is pretty wild.

 

[Ziploc]

You tube . D-Rail .

 

[9C1Driver]

Kind of off topic but who tuned the radio and what final does it have? I've saw some hot ones but 18 bird is pretty wild.

Yea i'm just not seeing a Cobra 29 dead key 18 watts. That said if you end up getting that amp set the radio dead key to what ever will key the amp on hi at say 30-50 watts. If the radio will swing to say 16-20 watts that should be plenty.

 

[nomadradio]

A pair of SD1446 requires scandalously little drive power.

Base radios built by RCI used a pair of that transistor for a year or so. Drive power between 16 or 18 Watts peak was all it took for 180 to 200 Watt peaks coming out of the amplifier. Typical carrier power was around 3/4 of a Watt to get about 30 Watts carrier out of the amplifier.

If the amplifier has a High/Low switch you might be okay with it set to Low.

Simply reducing the carrier won't prevent the modulation peaks from overdriving an amplifier. That radio is twice the size that's right for those two transistors. If you have a High/Low switch that cuts the drive in half when set to "Low" that should be about right.

And feeding 40 Watt peaks directly into those transistors will wear them out prematurely.

73

 

[Ziploc]

Thanks why on low ?

 

[999]

Thanks why on low ?

Because that adds a "pad" (resistor) into the RF line and drops the amount of drive that the transistors see.
You have to remember that these amps were designed before the dual final radios and all of the 100/200/400 watts radios that are sold today. They were meant to be driven by a single final CB radio, and that was it. You can get away with an old school dual final radio with most amps, and even some of the mosfet ones. But once you start getting the drive level up to what you're talking about, it's starts to be much safer to run a straight 4 pill or larger. That will do two things...keep you from over saturating the transistors, and let them live a lot longer.

 

[Ziploc]

Ok thanks. I saw a you tube vid on a radio with 35 watt peak and wasn’t much different in power on med and high . What would low power peak ?

 

[2NC995]

You'd be looking for the same peak output from the amp, you're just getting there by running in low to put the input padding to use.

 

[Ziploc]

Ok thank you.