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Re: [Amps] Hmmmm...Legal limit boiled the oil in the cantena

To: donroden@hiwaay.net
Subject: Re: [Amps] Hmmmm...Legal limit boiled the oil in the cantena
From: Gudguyham@aol.com
Date: Wed, 7 Apr 2010 03:20:11 EDT
List-post: <amps@contesting.com">mailto:amps@contesting.com>
These meets are called SHOOT-OUTS
 
 
In a message dated 4/6/2010 11:48:53 P.M. Eastern Daylight Time,  
donroden@hiwaay.net writes:

All I  can tell ya was that I had a couple of 3 1/8 inch coax Bird  
In-Line  sections with 50KW elements and they were asking if I had  
anything  bigger.

The area behind the second seat was all "open construction"  with a 2  
inch diameter antenna sticking out of the roof and looked  to be  
capacitivly coupled to the anode of the 4CX15,000 without the  benefit  
of any matching network.

maybe a half wave  vertical  ( ?? )


The guy said he had just been on a contest  held in Atlanta at a  
Mariott near Hartsfield International, and  someone from the airport  
"ran them all off", threatning to call the  FCC.

Some of the cars have remote keying and the "operator" can get  fifty  
or sixty feet away before turning on the juice.

They  say it's impressive on a humid night.


Don  WA4NPL






Quoting Roger  <sub1@rogerhalstead.com>:

> It's all for show.  They  don't need near that HP to run them, they  
> don't need nitrous  oxide.   More than likely the crank broke from  
> the  acceleration and extra power from the nitrous oxide.  Figure the   
> monstrous SWR from a mobile antenna being fed 75000 watts. It'd  look  
> like a lightning generator. But it's unlikely they can do  better  
> than 50% efficient with the setups. So given 150 KW  input they need  
> 201 hp plus change. Given the generators are  not 100% efficient AND  
> the output frequency will change with  RPM who knows what they get  
> out of  them.
>
>
> Carl wrote:
>>
>>> At 11:09  PM 4/5/2010 -0400, donroden@hiwaay.net  wrote:
>>>
>>>> peanut compared to some of the 11  METER MOBILE amps I have seen
>>>>
>>>> How bout  a 4CX15,000 powered by four 200 amp alternators in a  Suburba
>>>> with a big block 454.
>>>>
>  That sounds like they are actually using 48 volt alternators.    
> Figuring 60% efficiency gives  37,500 watts input. going   
> conservative means 37,500/800 amps = 46.8 volts which is close   
> enough to guess at the 48 volt alternators, which means over all  a  
> very inefficient system. OTOH even a 37KW, 240 generator  would only  
> take 49 HP plus change, neglecting losses so maybe  55 HP would be  
> needed.  They might have a problem fitting  that relatively small  
> generator under the hood though.   The setup described would have  
> power loss in the alternators,  loss in the inverters,
>>>     I  should be  able to drive that amplifier with my VW Beetle engine.
>>> It  should only take about 80 HP
> 80?
>>> where is all that  power going from
>>> the 454 bigblock with nitrous oxide  injection? A hundred hp would be
>>> a little less than  75kW.
>>>
> or about 45 KW output at 60% efficient.
>  Just remember these are for show, or they'd be coming from the  
>  shallow end of the gene pool.
> If they have to stick with 48V  alternators of less the systems are  
> going to be very  inefficient which means a lot of lost HP so far  
> more than what  we figure would be needed. OTOH it still doesn't come  
> to any  where near the amount they are using.
>>> Sounds stupid to  me.
>>>
>>> 73
>>> Bill  wa4lav
>>>
>>>
>> A cranks snout is its  weakest link and its not designed to be  
>> pulled on by a bank  of monster alternators. I dont know if the  
>> CBers are using  forged or cast cranks either but they do break.
>>
> My guess  is, that although the monster alternators don't present a  
>  tremendous load, what they do present along with the sudden  
>  acceleration does and would probably be the reason for breaking  
>  cranks.
>> Nitrous is stupid but probably the only viable option fo a  10  
>> second run. If done right it wont destroy the pistons.  A  
>> supercharger would be safer in the long run but thats in  operation  
>> all the time.
>>
> A super charger  or turbo can be hooked up with a bypass or pressure  
> relief  (waste gate) like they do with aircraft so over boost isn't a  
>  problem. With a manual waste gate they can be left in stand by  
>  except for the run.
>
> 73
>
> Roger  (K8RI)
>> Carl
>> KM1H  _______________________________________________
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>>
>>
>

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