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Opinion Please
- Thread starter wizard56
- Start date
You asked for opinions......
For durability go with a straight 4 transistor amp.
This will allow for more options with the radio in front of it.
Often part of the drive from the first transistor is bled off anyway, they make more heat, they draw more amps and it is doubtful that the guy in the other end will notice.
Now
If you are trying to milk every watt you can out of the amp then go ahead with the 1x4 with the 2290 driver.
That's my opinion and I am sticking to it.
73
Jeff
For durability go with a straight 4 transistor amp.
This will allow for more options with the radio in front of it.
Often part of the drive from the first transistor is bled off anyway, they make more heat, they draw more amps and it is doubtful that the guy in the other end will notice.
Now
If you are trying to milk every watt you can out of the amp then go ahead with the 1x4 with the 2290 driver.
That's my opinion and I am sticking to it.
73
Jeff
I have never been that much of a fan of driving 2879's with a 2879. The 2290 takes a bit less to drive it, but is a slightly lower output device.
For me I'd want the 2290. Others will disagree with me.
For me I'd want the 2290. Others will disagree with me.
Shadetree Mechanic
Delaware Base Station 808
The HG aren't as good as the old Toshiba, as I'm sure you have heard. Trying to get 1000 watts out of a 4 pill, the HG won't live as long. Reasonable output for 4 HG is in the 500 watt range and it should last forever. If you need more than that, I would suggest a 6 or 8 pill.
Thanks guys. Been driving an X-Force 40012 with a Magna Force 100. But the old X-Force quit and the Magna can't last forever. Was looking to save a few bucks but you have reinforced my initial logic.
The 40012 quit?
Let out the smoke or just stopped keying?
That is a fairly good four transistor amp with Toshiba's if it original.
They do have a habit of smoking the bridge rectifiers with the surge of that one big filter cap they used to smooth out the ripple.
73
Jeff
Let out the smoke or just stopped keying?
That is a fairly good four transistor amp with Toshiba's if it original.
They do have a habit of smoking the bridge rectifiers with the surge of that one big filter cap they used to smooth out the ripple.
73
Jeff
No smoke, it's only puts about half power and getting high SWR back to radio. Bought it used like 20 years ago figured I got my money's worth. Time for new equipment.
That sure sounds like something went south with the input matching network on the amp. Could be as simple as a cap, or a burned trace. Are the pills getting full voltage ? If it's not class C and has a bias network it would be worth checking that too....
I have a hunch that it might be much cheaper to fix the X-Force than buy a new amp.
Edit to add: Check the relays in the X-Force. I recently had odd problems with a Palomar amp that included high SWR from the radio, and it turned out to be dirty relay contacts.
The model number 400 means 4 Toshiba 2879 transistors and the 12 says biased.
Like a 60012 is six transistors with bias.
The base models used a unregulated power supply that floats at about 19 volts unloaded and pulls down when keyed.
If the 4 Toshiba's are good it is worth the money to fix they are like gold now.
73
Jeff
If you can post a picture of the inside of the amp.
How old is it?
The old ones were built by Carl before Arlin took over, things changed after that.
Shadetree has a thread here somewhere about rebuilding his 40012.
Or it's a 600 can't remember now.
73
Jeff
How old is it?
The old ones were built by Carl before Arlin took over, things changed after that.
Shadetree has a thread here somewhere about rebuilding his 40012.
Or it's a 600 can't remember now.
73
Jeff
Opinion?
A built-in driver stage is the devil's own invention. Better off with a straight 4. More audio. Wattmeter is not an audio meter.
73
A built-in driver stage is the devil's own invention. Better off with a straight 4. More audio. Wattmeter is not an audio meter.
73
I would contact Carl at Carl Built Amps. Since he built it new just have him fix it. The older amplifiers are so much better. Not a big fan of 1x4 or 2x4 amplifiers. You probably don’t even need the 100 as a driver to be honest.