4x 4cx250b Glen amp

[RFThomas]

Im sure there are many experts out there on ceramic tube amps . all i can get out of this unit is 1000 watts with bird43 into dummyload ! all the tubes test just like new in my pride dx-300. now i know these tubes use low drive in my pride dx-300 and my 2 tube john boy box .but how about the 4 tube setup ?need more drive ? any suggestions ..this unit looks to be verry well built with grid / filiment /and high voltage circuts all fused . can any one help ?


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[cram]

SHOULD BE 4CX350FS

 

[kswitchdr]

How long have you owned the amp ? Have you ever seen it do more than 1000 watts ? I am quite certain that you don't want to drive the 250b with very much. Maybe the power supply in the amp is only capable of making the amp do 1000 watts ? Probably not much help but maybe some things to consider,Mike.

 

[paws264]

Check the value of the screen resistors.

 

[stresstest]

Do you have some pictures of the amp. I believe this is the same amp I used to own some many years ago. Remember your using a bird so you're seeing RMS. they (mine) did about 2300 pep when I used a Yeasu FT-101EE driving it with about 100 watts pep

 

[stresstest]

just noticed how old this thread was .... oh well

 

[Captain Kilowatt]

Do you have some pictures of the amp. I believe this is the same amp I used to own some many years ago. Remember your using a bird so you're seeing RMS. they (mine) did about 2300 pep when I used a Yeasu FT-101EE driving it with about 100 watts pep

Holy mother of God. How did you manage to keep the tubes in their sockets when driving them with 100 watts? The 4CX250B is a very low drive tube with only 2 watts of grid dissipation.They typically require only a few watts for full output. Most amps using them in pairs can be driven to full output with just five watts drive.

 

[paws264]

Holy mother of God. How did you manage to keep the tubes in their sockets when driving them with 100 watts? The 4CX250B is a very low drive tube with only 2 watts of grid dissipation.They typically require only a few watts for full output. Most amps using them in pairs can be driven to full output with just five watts drive.

I built a 6-tube 4CX-250 box once and, it took 100 watts to drive.

It was Cathode-driven and each tube had a separate adjustable bias, a switchable meter was used to make sure that the tubes were balanced in idle.

300 Volts on the screen were controlled by three OC1 regulator tubes in series, I later went to zeners to control the screen volts.

Did an easy 4000 with a 3-phase AC supply and one Leece-NeVille.

Those were the 1980's.

.

 

[Rick0591]

I have been off radio for about 25 years now. Back in the day an amp would sell for a dollar a watt. I was told it is now .25 cents to .75 cents a watt. Anyone knows how much should i sell my Darke l-4b doing 2000 watts for. Someone has offerd me $1400.00 for it. Thank You

 

[nomadradio]

That's not a bad offer. Doing a fleabay search for that model clicking on "sold items only" would get you a ballpark of what people actually have paid.

Mileage is everything for an amplifier pushing 44 to 50 years of age. The easier the miles, the better the price, as a rule.

73

 

[TetroideTom]

Wow my old thread from years back. I wish I would have never sold that old glen renegade 2k. Oh well I now own two glen custom 2400b amps. But boy oh boy that Renegade would look nice next to them.

 

[linearone]

That's not a bad offer. Doing a fleabay search for that model clicking on "sold items only" would get you a ballpark of what people actually have paid.

Mileage is everything for an amplifier pushing 44 to 50 years of age. The easier the miles, the better the price, as a rule.

73

I only key my boxes on Sunday on the way to church. No deadkey, swing only. I keep the city miles low