|[AMRadio] Trouble brewing in the AM Window (or "Ghetto"|
ars.w5ami at gmail.com
Mon Dec 16 15:59:59 EST 2013
All this 20 to 30kw talk is just silly. If you think you need that much
overhead to last a "lifetime", then I say get a life. Sounds like CB talk
to me.... 'Nuf Said.
Brian / w5ami
PS: There is more to this story anyway, where did you come up with $14K
Billy? Thought your wife was begging for money on the internet just a few
years ago because y'all were broke? I could say more, but won't buddy.
On Mon, Dec 16, 2013 at 2:36 PM, Kim Elmore <cw_de_n5op at sbcglobal.net>wrote:
> That may not be the whole story. Yes, it's certainly possible to destroy a
> tube by pushing it beyond its design limits. But based on what I've read,
> what tends to do them in is power cycles on the filament: turning them on
> and off is a Very Bad Thing for big vacuum tubes. Thus, the tube in an amp
> or transmitter running a 4-1000 or, better yet, a 4CX15000 at significantly
> reduced output may still fail leaving the owner with a sizeable bill for
> replacement. In addition, if the glass envelope tubes run without color on
> the anode, the tube is not continuously gettered, which will also reduce
> usesble lifetime.
> Kim N5OP
> "People that make music together cannot be enemies, at least as long as
> the music lasts." -- Paul Hindemith
> On Dec 16, 2013, at 14:23, billy <kd5zla at swbell.net> wrote:
> > Here in Altus, OK 15 watts will give 1500 watts out and with just 3
> watts on AM will give me about 300 watts so the icom 706 will be happy
> there. I use to have Harris 103A that I modded to take a pair of 4-1000 to
> make it 50 OHM input It would do 1500 watts with 25 watts drive. So you ask
> why someone would want a amp that will do more than 1500 watts. Well look
> at it like this at 1500 watts the 10 k amp will run for ever and I will
> never have to worry about the tubes in it. You take any of the US made amps
> with the 3cx or 4cx tubes you are running those amps at 75% or more and you
> are going to have to replace the tubes and on AM they do not give you
> any head room and they will not be clean. You look back years ago Henry has
> the 5k, 8k, and 12k. But people wanted cheap. Just like today cheap sweep
> tube amps 811 or 572 and they are driven to the limits day in day out and
> they melt down the tubes.
> > On 12/16/2013 12:55 PM, W5AMI wrote:
> >> Where exactly are you planning to use this unit Billy?
> >> On Mon, Dec 16, 2013 at 11:57 AM, billy <kd5zla at swbell.net>
> >>> Just ordered the box with 2 GU78B's and got the auto tune network and
> he is building a antenna tuner for me as well total to my door was
> 14,225.00 I am now having to build antennas to take the power going to use
> number 4 copper clad and 7/8 in hardline for the delta loop and then going
> to gamma feed my 70ft tower
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