Looks like RF parts are selling those NOS. That's what the 2879's looked like a little while before they were never seen again. The legit ones anyway.
https://www.rfparts.com/rftransistors/transistor-rd/rd100hhf1.html
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Carl Built
- Thread starter Staybolt
- Start date
Looks like RF parts are selling those NOS. That's what the 2879's looked like a little while before they were never seen again. The legit ones anyway.
https://www.rfparts.com/rftransistors/transistor-rd/rd100hhf1.html
Everyone agrees the Xforce of a couple years ago was....a reason they're no longer in business.
Word on the street is the original X-force Carl made 10-15 years ago and his new Carl Built are satisfactory in quality and support for being in the 11m amp game.
Being that this is the only 100 watt, 12 volt HF part in use today, it absolutely must remain in production until a replacement is manufactured. What you are seeing at RF parts is the result of RoHS compliance and relates to the toxic beo ceramic insulator used in the best parts.
The new Mitsubishi replacement is the same part number, designated with a "G" at the end. This change is equivalent to Toshiba's adding the "C" at the end of the 2879. It is the same exact part electrically, although the insulator is slightly less themally conductive.
I've had over the years....back when Moby Dick was a minnow, a Davemade, Texas Star, Train Built, Bulldog (Skidrow), X-Force (used) Palomar, and some no name amp that I never could run because it had 36 or 48VDC transistors in it. Since I've gotten back into the hobby, I've been running a DonkeyStomper 1X4 and have had no real issues with it, other than over driving it, which is an idiot problem, not an amp problem. I have zero issue recommending DonkeyStomper amps and his CS is excellent. I trust him enough that I'm sending him my two Toshiba 2879s to have an amp built.
Arlen fucked Xforce up.
And im back in da bushes...
Still a little confused as I have seen similar posts and someone stating that a carl built and the like are built differently, but they didn't know how. Same as the videos testing carls 400hdhg when they put 80pep in saying its only about half of what the amp can handle. Myself, I guess I'm going to stick to transistor specs until I find out differently. Also messaging Carl and asking him, how.
Shadetree Mechanic
Delaware Base Station 808
The drive power will determine how long the transistors last. Overdriving will cause the gain to go down. Then most people will turn the drive up even more to try to get the big numbers they used to have. Then repeat this cycle until a transistor blows. I would say that 80w peak on a 4 pill would be the most I would try. And 40w peak would let the amplifier live a long time.
Don't forget class c will out perform a/b. Im wondering if the differences you're seeing may be due to the amp class? I see carl pull 1275 peak and 520 average from his 4 pill with 200 watt dk
Personally I wouldnt expect to see more than 600-700 watts peak for any length of time safely from an hg non "C" 4 pill at 14.5 volts and 50-80 watts peak input.
Lots of variables.
And you gotta keep in mind these builders are running the supply at 15vdc into a dummy load with max drive they can push witbout blowing it up. Why? To show huge numbers and increase sales. In the real world 14vdc on an antenna with proper drive levels you will see half to three quarters of what they show on video.
Yes, he says they are class C amps. That's why I'm asking this if I really should be pushing more because it's class C or stick to the specs no matter what as I've also seen a couple posts where people have blown Carl's 400hds out with the 955, doing 80 Watts peaked out. That being said I'm not sure if the 955 was the reason or if there was another issue they had going on.
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Yeah that I do realize that as well because the ones that are showing they are doing high-power besides Carl are radio shops. The one video I saw at Bells CB was showing almost 500 with a stock radio and then he hooked up 2 2290s doing 160 and got 675 which to me is probably more close to normal readings than the thousand plus Watts others are showing.
Drive your amp according to manufacture specs of the transistors, not what the builder says it can do
Therein lies the problem. The only specs for HG are copied Toshiba data sheets and we all know hg will not withstand what toshibas will. It used to be fairly easy.
Yes, still coming back to that myself. Going by that if I got it right, it says the lowest IMD is at 60 pep out with about 2ish pep in. If I get the 955 which when tuned does around 60 watts where I buy them, to start I could drive a 30 "pill" forever and clean as well LOL?! If I figured it correctly. If incorrect sorry, worked a double really tired LOL.
If you treat HG 2879s like 1446s, they'll last forever, but running them like Toshiba 2879s trying to get the same performance will cause a lot of smoke.... I have 3 dead transistors to prove it. Also, they don't like 16 volts for long and 1.6 SWR for extended periods of time will kill them.