Hello Jim and group, I respectfully disagree. Tube amps are not a thing of the past nor will they be for a long time to come. I would like to point out that I own and use both Solid state and Tube am
Jaw. If you over drive them it can be a quick death, while a tube will take an occasional over drive." Current SS amp protection circuity is very good and getting better all the time. In the case of
I am very familiar with that as I built one also, The issue is anyone who builds one must face that issue one way or the other. Any mistake and it is over. As I said, I have both LDMOS and Tube ampli
Although I agree, I would modify the conclusions a bit. High power semiconductor device technology is becoming more mature, with the result of longer device life cycles. Also, the longer a device rem
Author: Herbert Schoenbohm <herbert.schoenbohm@gmail.com>
Date: Mon, 5 Jun 2017 06:36:47 -0400
Tubes in High Power Amps can take a licking and keep on ticking...but not solid state amps devices. Replacing power MOSFETS in RF pallets is much more complicated. ___________________________________
The current crop of new devices is likely to be around much longer than devices made just 10 years ago. Given the trend to pallet based amplifiers, I doubt the device shelf lifetime will be very lon
Yes, ham gear needs to be based on the RF PA equivalent of the 2N2222 and 2N3055; devices that have many uses, are fully mature, and won't be readily obsoleted by new tech. We may need to see solid
<Tubes in High Power Amps can take a licking and keep on ticking...but not solid state amps devices. Replacing power MOSFETS in RF pallets is much more complicated. not much better, at only 1 watt. T
I've long wondered what the zero watt rating of the 4cx1000 grid actually means. I've assumed it means the tube is rated for class AB1 operation only, and that the rating doesn't reflect the actual p
Hi Jim, I think that the 4CX1500 has the same grid as the 4CX1000. Somewhere I have seen it written by Eimac that it is ok to draw a small amount of grid current during brief tune up. The Collins 30S
I have never liked the 30S-1 grid derived ALC. The grid voltage is passed through ( essentially ) an audio transformer and the tube has to draw grid current before the transformer's secondary is rect
I just cut the anode off a dud 4CX1000A. The control grid structure cannot be seen until I determine how to cut away the screen grid without destroying the control grid which I am going to guess is n
Add to that, the lack of knowledge in electronics, building, and the general age of "old timers", module / pallet replacement seems even more likely. Most of today's rigs use an output module. It's p
Good Afternoon Roger! With the Solid State Amps, which I'm Thinking of getting one, I too believe that the parts May begin to be "More Available" as they "Age". I would Hope that Someone would "Pick
-- ORIGINAL MESSAGE --(may be snipped) REPLY: You'd have to be pretty careless to damage the grid of an 8877 since it is rated at 25 watts dissipation. The normal dissipation at 1500 watts output is
When in use, transistors do age. It's caused by the migration of the majority carriers migrating across the junction causing the majority carriers on one side to cause an increase of minority carrier