Palomar 600 Elite: How Many Input Watts Are Too Much?

[Robb]

Got a Palomar 600 Elite her that I'm working on for a friend.
How many input watts are too much for this unit? I cannot find any schematics for it either. Anyone have some good links for it? I think the transitors are 4/1446's - but not sure yet.
Thanks in advance...

 

[Robb]

I know this is a fairly rare amp.
But doesn't anyone own one or had to work on it before?

 

[BOOTY MONSTER]

use an external power meter and set the radio to make the amp deadkey about %25 of what it will cleanly swing . 450ish for four 1446's , even if you got 600 out of it it wouldnt be as clean and would have very minimal effect on your tx . IMO

 

[Switch Kit]

Pal 600 is not rare , it should be 1 driving 4 ? 4 x 1446s would be concidered a 450 . Drive you ask ? ......Would be very close to the same weather it's one driving 4 or just a stright 4 . 1 to 2 watts tops , and I would figure more on the lines of 1 watt with the amp having a driver in it.

Pep drive would be a good question from there ? Is it a high drive box ? I would doubt it ...but you never know. Amps are not all created equal. I've seen 4 x 1446s do 500 pep watts on a Bird 43P with a 1.5 watt DK with a 20 watt swing. that was pretty much 125 watt DK x 4 pep swing.

The 1446s got mojo balls when it comes the 11 meter band ! A very impressive transistor to say the least.

 

[9C1Driver]

I agree Switch, the Palomar/Gray/Boomer 600 were all a 1 driving 4 setup.

 

[Robb]

It looks like it has one MRF455 and four SRF3749's in it.
I'm not sure that the SRF3749 number is a good number, as I don't know that much about amps and the output transistors in linears.
Anyone familiar with these transistors?

 

[Switch Kit]

3749er's are 80 watters . (-:

 

[Robb]

The MRF455 is the driver; so what would be the peak amount of input watts for this unit?

 

[Switch Kit]

realistically ? that's one thing , a radio doing 1 to 20 I don't see why it couldn't do at least 500 watts pep with the driver. I suppose you could do the realistic type math , 4 x 80 = 320 , I'd say it was a HD amp having the driver at 50 to 60 watts pep into that ,

You really have to have a good understanding of how these things work . Experiance is one thing , understanding knowledge of given device is another.

I see Freecell floating around , he likes to answer questions in a more "realistic" type fashion.

 

[Robb]

Let me re-phrase my question...
The output of the radio goes into the linear - let's say it is 20 watts PEP...
Now, is that too much for the MRF455 to handle and still be undistorted for the final transistors to amplify?
How may WATTS can the input of the amp handle?
Is it a high drive amp - or a low drive amp
Thanks!

 

[Switch Kit]

Is this your buddies box ?

 

[Robb]

Yep. That's it...
I replaced a 1000mf/16v with a 1000mf/25v cap that I had. The one I took out looked like it had expanded too much at the top.
The box was 'motorboating' and causing the relay to switch on/off constantly. Also, the power wires to the board had crappy solder joints - so I resoldered them and now there appears to be no problem with it. It's working fine now - and hasn't had a problem for the past two hours. I wanted to know if the radio he was using was overloading the input of the amp. The owner of the amp has got a Cobra 148 GTL that I've worked on and fixed.
Thanks!

 

[BOOTY MONSTER]

do you have a watt meter that will measure up to 500 watts ? or can you borrow one ?

 

[Robb]

Booty Mon;
Yes, I have a Dosy TC-4002-SW that can handle 4000 watts. This Palomar dead keyed at 200 watts on low and swung up past 300 watts easy.

 

[Moleculo]

The key on an amp like this is to not overdrive the first stage, in this case a MRF454. With that transistor, you're looking at like a 2 watt carrier, or maybe even 1.5 watts. From there, about 16 watts will probably make it do all it should do and still be clean. You might be able to push it a little bit more than that, but I wouldn't think you'd want to go much more. Those type of amps were really intended to be used with very stock radios with the carrier reduced a bit.