Palomar 600

[nomadradio]

An ideal amplifier would be stable no matter the SWR of the antenna, or the length of coax jumpers.

But real-world amplifiers will be affected by those factors, like yours was.

Predicting what kind of trouble might accompany a particular choice of vehicle, antenna mount, antenna and coax jumpers sounds a bit like relying on a ouija board.

Sure wish I could predict how those factors affect an amplifier.

73

 

[9C1Driver]

I hope you all don't think I'm hijacking the thread, but I'm having issues with one of the amps. Might help OP as well. Mine amp is a 600 and I just had my Galaxy 88HL's dead key matched up to the amp on the low power setting. I think that radio swings about 20 watts.
On the bench, I was getting 100/500/550 on the different settings looking at my receipt. In the truck running a Wilson 5k, I was getting a nasty squeal and amp was locking up.
So yesterday I carried the truck over to the shop and the tech worked on the truck. SWR's were high, so he first brought them down to 1.2. Then with the amp on, it was over 3.1. We used different jumper lengths and got the amp so it wouldn't lock up and the squeal went away, but the best we could get the SWR's was 3.1.
I wound up putting my Boomer 4 pill in line and now I'm rocking and rolling. I am going to try the 600 in another truck with a different radio and a Wilson 1k and see what it does. I hate to sell it to someone, and they have problems. My radio guy says these amps have a history of this sort of behavior. He doesn't mess with them. Any suggestions? Anyone techs out there that can fix these issues?

Many of these Boomer/Palomar/Gray amplifiers behaved like this. They were not tuned well for a 50 ohm load, this mismatch causes a high SWR. The amp will have to be worked on or the best you can do is try to fool the meter with longer jumper lengths.

 

[my2995dx]

Remember that AM-only models like the 44 drive the final transistor in class C. Makes it more efficient. Can't do that in a SSB radio. Takes two sideband-radio finals to reach 35 Watt peaks, more or less. We're accustomed to seeing 28 Watt peaks from the single -final AM-only "10-meter" models. The difference between 28 and 30 is next to nothing, statistically.

73

So for fun I grabbed my old 29ltd with variable started to play radio alone keys 0.5 watt now with amp on it's 100 and it swings if I try to lower dead key then the amp clicks in and out.So 0.5w is good any higher on deadkey less output