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reinventing the wheel? looks like a davemade 5 pill, are you talking about the bias circuit that has been added to it?

That is true Bob. I love to help people out but it seams that most of them have ulterior motives. I know that RF amplifiers can be a big pain in the ass but if folks are just wanting to copy so they can make a buck I got nothing for them.

Good subject, I would elaborate more but I am nursing a solder smoke hangover :laugh::laugh:

I was referring to the copycat amp "assemblers" that have hit the CB scene, not you ken;)

There has been many times that I wanted to bring a thread like this up but never did because I knew when I posted it that peoples mouths would watering with the thought that they might get to learn the right way to make an amplifier for a modulated signal.

I know I have a hand drawn schematic of the circuit I used. I will look for it. If you find your drawing or if someone else has it that would be cool. Just PM me.

I agree.

If you would prefer I will not even discuss on the matter.

Bob I used transistors base emitter junction. to track heat. It worked ok but I have since improve a little on the way it tracks. That amplifier was switchable between AB and C I believe. I need to try and dig out the hand drawn schematic of that design and pm it to you.

How are you guys tracking heat in your bias designs? Wanna trade schematics through PM's?

Why not start a discussion about the various bias designs, filtering and just basic theory based around transistorized RF amplifiers. Swap ideas, schematics etc. etc. I will start off with my first intro into it. How many of you guys use a transistor to turn on the bias supply at keyup...

Yeah it is the real peakaboo. I had to rejoin for some reason. Its me though. I never quit tinkering I just laid low and slow. JJD, what PM? When? I have been answering a lot of PM's. I looked through them and did not see one from you.

I am trying to find the date I joined. I am CDX-10

I would recommend a 200 amp unit:D:D

Should be fine if it worked when parked.

Choices choices choices:D

I was just curious of the way others were doing it. I rarely see the RM amplifiers but had someone ask if I would look at one in a month or so and it just struck my interest. As some may have seen I have been using the same bias scheme since the 90's and for the most part it works pretty good...

Normally no one wants great details done to these little amps. I have not had one on my bench in a while I was just curious as to what everyone else was doing. The one I did "tweek" on I just relocated the small diodes to the top of the "pills" I am in the process of redoing the bias circuit I...

Speaking of RM Italy, didn't I see a discussion somewhere about adding thermal tracking to some of the smaller RM amps? If so how are you guys doing this? I get these little amps in for repair sometimes and usually just make them work again but was curious of what the people modding them were doing.

Looks familiar:biggrin::biggrin: