I just acquired this Drake L-4b as the third owner and no nothing about its history. It puts out 400 watts with recommended Plate and grid currents (.56 amps, and 225Ma respectively). If overdriven (
1) Take out the Old, put in the New. 2) Let them warm up a few minutes 3) Enjoy! _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mail
Of course, the finals in the Amp are push pull configuration -2k PEP & 1K CW input watts. That is incorrect. The L4B (and L7) are parallel 3-500Z designs. If your "new" tubes come from Drake, they ar
One common suggestion is to run them first on the lower voltage CW setting but leave the key down long enough to get the anodized nice and red. Do this for several times and then use them normally in
Larry: Congrats on adding the L4B to your shack. I have owned both the L4 as well as the L4B. It sounds like the tubes in the amp are soft. You should see 600-700 watts out with 80 or more watts in f
Please accept apologies - I misspoke on being push pull - surely finals are in parallel - I was more focused on trying to explain simply and 'fingers did their thing' again, sorry for misspeaking. La
Seems odd that you say overdrive giving 100ma of grid but 400w with 225ma grid.. This is perhaps a tuning issue with mis adjusted loading. Are you using relative output and grid current to tune or tr
Better yet... How much drive are you putting into it? What radio are you using? Jim W7RY On 12/23/2022 6:36 PM, Curt Nixon wrote: Seems odd that you say overdrive giving 100ma of grid but 400w with 2
I didn't understand the original post, either. 800mA Ip is not overdriven if the Ig is below 300mA. 800mA is the rated Ip for two 3-500Zs, and they're rated for that under CCS (broadcast) conditions;
An extra good method, go to cw, run dots about 20 wpm and tune for max. Do a carrier (rtty), check meters, run load knob clockwise, drop power a few watts and watch Ig drop in half. Remember these am
Author: gudguyham--- via Amps <amps@contesting.com>
Date: Sat, 24 Dec 2022 02:04:08 +0000 (UTC)
Henry amplifies ran a pair of 3-500 tubes up to 2000 watts output. You simply cant over drive a pair of 3-500s with a Drake L4 amplifier unless you drive it with 125watts or more. That doesnt mean
<I just acquired this Drake L-4b as the third owner and no nothing about its history. It puts out <400 watts with recommended Plate and grid currents (.56 amps, and 225Ma respectively). If <overdrive
The author originating this discussion said that they had one 3-500Z that was the vertical thin fin plate, Eimac original, and one 3-500G that has the graphite anode presumably with the horizontal he
The original poster said they were in original Drake packaging. If they were in fact in original sealed Drake boxes I wouldn't worry about using them together as Drake would have sold them at differe
The Collins 828C1, and Continental 314R1 1kW medium wave transmitter used a single 3-500Z as a switch tube running at 70 KHz switching frequency for pulse width modulated AM. It was very picky of the