Hi all, i am researching the feasibility of building one of these over the summer. I have a set of plans for building a 2 driving 4 6LF6 tube amp, but obviously these tubes are far too obsolete and expensive to consider using. Yes, EL-509's would work, but im thinking of using a real transmitting tube that will be around for a while to come.

Amplifier homebrewing. This is the original WB0NNI scratch built RF amplifier site. Circuit improvements for the Heath SB-220 Amplifier, etc. Some components by Richard L. Measures, AG6K. Home Brew Amp Project - NI4L QRO GU-84B TETRODE. This amplifier circuit is used to amplify TV signals in UHF range. It uses a low-noise transistor. Simple Cable TV Amplifier Circuit P.

Yes, i also know that i could make a single tube amp, but i think ill be happy using the 811a's. I want to do a 1 driving 4 grounded grid configuration, and i want to know how this will work. I have an old kenrich 2 driving 5 20LF6 amp that i would like to scrounge as many parts from as i can. Is this possible? Is the plate voltage required for the 811a's too much for the components in the kenrich amp such as the tune and load caps? The plans i have are basically to build a palomar 350z amp.

So can it be done? Hi all, i am researching the feasibility of building one of these over the summer. I have a set of plans for building a 2 driving 4 6LF6 tube amp, but obviously these tubes are far too obsolete and expensive to consider using. Yes, EL-509's would work, but im thinking of using a real transmitting tube that will be around for a while to come. Yes, i also know that i could make a single tube amp, but i think ill be happy using the 811a's. I want to do a 1 driving 4 grounded grid configuration, and i want to know how this will work. I have an old kenrich 2 driving 5 20LF6 amp that i would like to scrounge as many parts from as i can.

Is this possible? Is the plate voltage required for the 811a's too much for the components in the kenrich amp such as the tune and load caps? The plans i have are basically to build a palomar 350z amp. So can it be done? Basically, build a 1 driving 4 sweep tube amp but use 811a's?

Any insight is appreciated. Click to expand.Yes, it could be done but, think along different lines and come up with a better amplifier.

The 811a tube was originally designed for audio use and it really wasn't for use at RF frequencies but, what do I know, the manufacturers use them all the time (but you don't see them operating above 30 MHz). The 572b tube is the beefed-up RF version of the 811a and, it fits in the same tube socket and has the same voltage and current requirements. If, you were to build that amp as a single stage model with 4 X 572b with the right B+ transformer you could see 1200 watts PEP or more. There is not much you can get from the Kenrich amp chassis, plus, you are wanting to build a reliable amp, you are better off buying new or surplus parts for your project. Get all of your parts and then lay them out on you 19' chassis; under the bottom, separate the input section and output sections with metal walls.

Buy yourself some air variables (out of a Heath-kit or buy vacuum variables on eBay). PM me if you get beyond the contemplation stage. Yes, it could be done but, think along different lines and come up with a better amplifier. The 811a tube was originally designed for audio use and it really wasn't for use at RF frequencies but, what do I know, the manufacturers use them all the time (but you don't see them operating above 30 MHz).

The 572b tube is the beefed-up RF version of the 811a and, it fits in the same tube socket and has the same voltage and current requirements. If, you were to build that amp as a single stage model with 4 X 572b with the right B+ transformer you could see 1200 watts PEP or more.

There is not much you can get from the Kenrich amp chassis, plus, you are wanting to build a reliable amp, you are better off buying new or surplus parts for your project. Get all of your parts and then lay them out on you 19' chassis; under the bottom, separate the input section and output sections with metal walls. Buy yourself some air variables (out of a Heath-kit or buy vacuum variables on eBay).

PM me if you get beyond the contemplation stage. Click to expand. Actually the 811A is a very good RF tube providing it is operated within it's limits. Do not exceed 65 watts plate dissapation and do not exceed 1500 volts on the plate.Max plate current is 175 mA per tube. While the 572B is basically a beefed up version of the 811A the voltage and current reuuirements are not the same other than the filaments.The 572B likes to be run near their max plate voltage of 2200 volts and will withstand a plate current of 275 mA per tube.They will handle 160 watts of plate dissapation however. I believe Svetlana specs their 572B for 2750 volts but I would not do that regardless what they say. That is a little extreme.The Svetlana 572B is a differant animal and is built for the audio market, not the RF market.