Teflon is rated for 1500 kv per inch. .040 thickness is good for 60,000 volts! You can find the info at google "teflon voltage". A typical application is for a plate bypass at VHF or UHF where 5 to 1
You are right Dave, the dielectric constant is about 2.3. But, you can use much closer plate to plate spacing and that will increase the total C many times. 73, Gerald K5GW In a message dated 3/15/20
What a concept! pF AND voltage in a spray can. I like it! 73, Gerald K5GW In a message dated 3/17/2010 8:55:42 A.M. Central Daylight Time, Jim.thom@telus.net writes: Carel I am pleased that you check
Isaac, considering the amount of capacitance from cathode to grid, it is pretty hard to actually make a T circuit. You might as well use the capacitance as part of a pi net and have all of the advant
I might as well throw in my 6m input matching experience: I have an Ameritron AL1500 (uses 8877) converted from hf to 6m a few years back. This amplifier had the input tuned circuits inside a 4" X 4"
Herzog, Bill and all, It is a good thing that the input power and output power are in phase else the input power would subtract from the output power instead of adding. I was reading in my Orr's Hand
How does that old saying go? You can't work them if they can't hear you? No, that's not right. 73, Gerald K5GW In a message dated 3/29/2010 7:48:47 A.M. Central Daylight Time, sm2ekm@telia.com writes
Bill, back in those days many, if not most, of us were building our amplifiers. As a result, there was a lot of "chatter" about them at club meetings and on the air. With all that chatter came the ol
I will display some ignorance here: Does the plate current waveform distortion cause any problem at the fundamental frequency? Your idea for using a quarter wave stub like that is interesting. For a
It is all part of the show! 73, Gerald K5GW In a message dated 3/30/2010 12:14:23 P.M. Central Daylight Time, wlfuqu00@uky.edu writes: I took a look at the bunch of idiots doing the shoot out and try
After more reading in the Orr book, I discovered a discussion of feed through power in a cathode driven amplifier. We have all heard about the drive power adding to the output power. Orr says, and I
Larry, I wonder why your aversion to using water? 73, Gerald K5GW In a message dated 4/5/2010 11:07:23 A.M. Central Daylight Time, larry@w7iuv.com writes: The recent discussion on water cooling amp t
I don't think we have spent nearly enough time on this topic. Here is a plan to determine the validity of rf flowing through a piece of metal: Connect a 1000 pF capacitor with two inch long leads to
Jay, you might want to make sure the bandswitch shaft hasn't slipped and the input part is not on the band you think it is on. 73, Gerald K5GW In a message dated 4/7/2010 12:48:15 P.M. Central Daylig
I know now, but when I started the answer and before being interrupted six times, there was no answer. I didn't think about going back to see if anyone had answered before hitting the send button. Ve
We all know there HAS to be some kind of matching to get significant power transfer. It could be this simple: The rf choke could be sized to provide the needed inductance for an L match. The series c
Roger and all, re: Chinese vacuum relays: I have purchased a couple of these from Gigavac in the last year. I have to say that they work great and look great. I would buy more as needed without hesit
The corona ball at the tip of a mobile antenna is really important to proper standing wave management. If it is completely symmetric, then omni-directional radiation is assured. If it is asymmetrical
With the shunt C from tube anode to ground there would not be a case for 50 +j0 right at the tube. Also, with tube in the discussion the plate load impedance would be a bit higher than 50 ohms anyway
Q=X/R in a series circuit or R/X in a parallel circuit. Since at resonance there is 0 ohms X in the series circuit or infinite X in the parallel circuit, The Q would be 0 as in zero. No flywheel acti