What I remember about this particular amp is the same as all the other RM Italy transistor amps. You have to keep the drive really low. What kind of power are you putting into it?
73,
Brett
73,
Brett
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RM Station 550
- Thread starter redlght
- Start date
Pins 1 & 2 on the jumper. How technical can you get comfortably? Do you have good voltmeters, oscilloscope?
According to the manual 1 to 10 watts AM or FM. Read that as dead key power since FM does not change in amplitude with modulation.
2-20 watts SSB or CW. That's as per the owners manual operating manual.
Tomorrow after noon I can set it up and test it. I don't know if it works or not but I'll find quick enough. Certain things like the voltage to the finals should be okay. There are no blown fuses in it.
But for now I'm dragging my butt to bed.
I do have ideas of what to check, but that is for tomorrow.
But for now I'm dragging my butt to bed.
I do have ideas of what to check, but that is for tomorrow.
Redlight, Tallman is good people and knows those RM Italy amps pretty well. He will get you an answer. He has worked on a few of those RM Italy amps from what I have heard.
Hope you get it working how you want. I do know that all the ones I've heard on air or heard about, don't like a lot of dead key power, and they don't like a lot of PEP power either. Keep the power set low and focus on getting a clean signal out versus how much power you get out of it as long as it appears to be working properly. It might only take .5 watts of dead key or possibly less and about 8-12 watts on SSB and about 8 watts pep on AM to make it work correctly. Like I said, get a clean signal and also a good 1:4 ratio of power. So if it dead keys 40 watts, PEP power should be about 160 watts give or take a few watts. Don't always believe the manufacturers figures for input as you may find it very different from what they are listed as. And that goes for a lot of amps out there, not just yours. JMHO's. And again, hope you get it working the way you would like it to.
73 and God Bless
222DBFL
Hope you get it working how you want. I do know that all the ones I've heard on air or heard about, don't like a lot of dead key power, and they don't like a lot of PEP power either. Keep the power set low and focus on getting a clean signal out versus how much power you get out of it as long as it appears to be working properly. It might only take .5 watts of dead key or possibly less and about 8-12 watts on SSB and about 8 watts pep on AM to make it work correctly. Like I said, get a clean signal and also a good 1:4 ratio of power. So if it dead keys 40 watts, PEP power should be about 160 watts give or take a few watts. Don't always believe the manufacturers figures for input as you may find it very different from what they are listed as. And that goes for a lot of amps out there, not just yours. JMHO's. And again, hope you get it working the way you would like it to.
73 and God Bless
222DBFL
I printed out both of the schematics and compared in a couple of places and the reference designators are the same.
I only took a couple of voltage measurements so far I had to take it all down for Sunday lunch.
Here is what I read On the collectors of the RF Final transistors 33.8 volts unkeyed. On the Bases of the RF finals .65 Vdc with no signal in put. Manually key the amplifier by taking the collector of TR-3 TO GROUND with a jumper. Don't keep it keyed too long in this condition, just long enough to get your reading. If you have two volt meters monitor the output supply voltage for the radio it should not dip below 12.8 Vdc when keyed.(No radio connected)
I'm getting ready to scrap this amplifier out and keep just certain parts. If you want it just pay for shipping.
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Aww shucks, now I'm starting to blush. Thanks 222DBFL.Redlight, Tallman is good people and knows those RM Italy amps pretty well. He will get you an answer. He has worked on a few of those RM Italy amps from what I have heard.
I know who knows what! I just tell it like it is!! Hope all is well with you and the lovely Mrs. Its been hot down here. Going to be a beach Christmas LOL!! No cold. But possible sunburn!! Have a great and Blessed Christmas. Soon I'll be catching you on the other bands! February is just around the corner!! Anyways. Have a Merry Christmas and hopefully will talk with you before the New Year.
73 and God Bless.
Sean
73 and God Bless.
Sean
