[Amps] Fwd: Re: Bill Orr comment

Fri Jul 25 08:56:49 EDT 2008

I go thru the same search Mike. Its seldom that I have to find one as 
usually the customer prefers to provide it. Often I could have saved him 
hundreds but you know how hams are sometimes (;

OK on the Ameritron choice, I wasnt aware of that. I did have to order 
several items from them the other day and just happened to see an 8877 for 
under $400 so figured it wasnt an Eimac!

Not sure why but Im getting a big increase in repair work the past 6 months 
or so. Must have been a lot of DXpeditions in action!

Carl
KM1H
6M amp conversions and repairs since 1964

----- Original Message ----- 
From: "Mike" <noddy1211 at sbcglobal.net>
To: "'Amps Reflector'" <amps at contesting.com>
Sent: Thursday, July 24, 2008 10:54 PM
Subject: Re: [Amps] Fwd: Re: Bill Orr comment

> Thanks Carl, sorry for getting your name spelling wrong.  I think I will
> take your advice and see if I can get a medical pull, I see them from time
> to time on eBay, unless you know of a better way to get the medical pulls.
> I just want to keep a spare in case of fatal failure in a contest.
>
> It looks like if you buy an amp from Ameritron they give you a choice 
> 8877's
> about 400 bucks cheaper for the import tube fitted.
>
> Thanks again,
>
> Mike
>
> -----Original Message-----
>
>
> Ive no experience with the Chinese version Mike but I believe that is what
> Ameritron uses now and sells direct at a much lower price.
>
> When needed for a job I stick with Eimac 3CPX or Y-xxx medical pulls of 
> near
>
> full output.
>
> Carl
> KM1H
>
>
> ----- Original Message ----- 
> From: "Mike" <noddy1211 at sbcglobal.net>
> To: "'Amps Reflector'" <amps at contesting.com>
> Sent: Thursday, July 24, 2008 10:04 PM
> Subject: Re: [Amps] Fwd: Re: Bill Orr comment
>
>
>>I know, just making a point that the tube will easily do more than 1500
>> watts, as the other guy stated.  I am more than happy having that tube
>> running at 1200 watts and hopefully lasting for a few years that way.
>>
>> I am sure the IMD plots would look wonderful at 2600 watts SSB:-) I would
>> be
>> the only station on 17 meters.
>>
>> By the way Karl, I was going to buy a spare tube and I see some for sale
>> for
>> around 600 bucks, but they are imports, I guess Chinese, are they as good
>> as
>> my Eimac 8877 original?
>>
>> Mike
>>
>> -----Original Message-----
>> From: Carl [mailto:km1h at jeremy.mv.com]
>>
>>
>> Not unusual since it is seriously overdriven. Id love to see the IMD plot
>> on
>>
>> SSB at the same power.
>>
>> Carl
>> KM1H
>>
>>
>>
>> ----- Original Message ----- 
>> From: "Mike" <noddy1211 at sbcglobal.net>
>> To: "'Amps Reflector'" <amps at contesting.com>
>> Sent: Thursday, July 24, 2008 9:16 PM
>> Subject: Re: [Amps] Fwd: Re: Bill Orr comment
>>
>>
>>> My Al-1500 (8877) will do 2,600 watts into a dummy load key down on 17
>>> meters with 100 watts of drive as measured on an LP-100.
>>>
>>> Mike
>>>
>>> -----Original Message-----
>>>
>>>
>>> Bill Orr was hardly a quack. Very knowledgeable and nice guy, met him
>>> several times over the years. An 8877 will get pretty darn close to 2 X.
>>> It
>>> was used in at least one 2.5 KW commercial FM transmitter that I know of
>>> and
>>>
>>> by FCC rule the transmitter had to be capable of 110% rated power
>>> (2750W).
>>> And that is CCS!
>>> 73's
>>> Chuck
>>> W6RD
>>> ----- Original Message ----- 
>>> From: <k9mk at flash.net>
>>> To: "Commander John" <crazytvjohn at yahoo.com>; <amps at contesting.com>
>>> Sent: Wednesday, July 23, 2008 11:01 AM
>>> Subject: Re: [Amps] Fwd: Re: Bill Orr comment
>>>
>>>
>>>>
>>>>     I can't speak to todays class of ceramic tubes but in the 70's I
>>>> built
>>>
>>>> a number of 3-1000Z amps.  The rule of thunb for a well designed AB amp
>>>> was 2:1, output power vs. dissipation.  So, yes I agree with the Orr's
>>>> "rule of thumb" here.  The 3-1000Z typically did 2:1 RF out 80m-15m but
>>>> it
>>>
>>>> did require a well thought out RF deck.  I will not name names here but
>>>> I
>>>> saw a dozens of what I call stressed 4-1000A amps that made it to the
>>>> 2.5:1 ouput ratio.
>>>>
>>>>    It is probably related to the manufacturers design but I have never
>>>> seen 3KW from an 8877 or even 1600W from a 3CX800...  Either something
>>>> is
>>>> being lost in translation or it kinda makes you wonder about the claims
>>>> surrounding our modern ceramic tubes...
>>>>
>>>> 73's    Mike  K9MK/5
>>>>
>>>>
>>>>
>>>>
>>>> -------------- Original message from Commander John
>>>> <crazytvjohn at yahoo.com>: -------------- 
>>>>
>>>>
>>>>>
>>>>> Commander John wrote: Date: Wed, 23 Jul 2008 10:23:38
>>>>> -0700 (PDT)
>>>>> From: Commander John
>>>>> Subject: Re: [Amps] Bill Orr comment
>>>>> To: Peter Voelpel
>>>>>
>>>>> Who is this "quack" guru?
>>>>> john w9zy
>>>>>
>>>>>
>>>>> ~~~~~~~~~~~~~~~~~~~~w9zy
>>>>>
>>>>> Peter Voelpel wrote:
>>>>> 2-2.5 times the dissipation is normal.
>>>>> Assume 1500 out, at 70% efficiency that is 643W dissipation,
>>>>> 1500/643=2.33.
>>>>> Eimac claims 75% efficiency on their 3CX3000A7 datasheet in AB2.
>>>>>
>>>>> 73
>>>>> Peter
>>>>>
>>>>> -----Original Message----- 
>>>>> From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com]
>>>>> On
>>>>> Behalf Of Gudguyham at aol.com
>>>>> Sent: Mittwoch, 23. Juli 2008 18:30
>>>>> To: amps at contesting.com
>>>>> Subject: [Amps] Bill Orr comment
>>>>>
>>>>> I was reading the Bill Orr handbook and on his section about 
>>>>> amplifiers
>>>>> he
>>>>> says.....A properly designed grounded grid amplifier should produce 2
>>>>> to
>>>>> 2.5
>>>>> times the plate dissapation of the tube in output. He did not put any
>>>>> limitations on the statement as to IMD or anything like that. He did
>>>>> not
>>>>> say if the tubes ratings would be surpassed (I am sure they would), 
>>>>> but
>>>>> I
>>>>> think what he was saying is that the tube should continue to make 
>>>>> power
>>>>> to 2
>>>>> to 2.5 times it's dissapation before it would not make any more power
>>>>> and
>>>>> flatten out.
>>>>>
>>>>> Upon speaking with an amp "Guru" about this subject, he procalimed 
>>>>> that
>>>>> Bill Orr was a "QUACK". The basis of his claim was that he was never
>>>>> able
>>>>> to build an amplifier that obtained that kind of results.
>>>>> What say you? Lou W1QJ
>>>>>
>>>>>
>>>>>
>>>>> **************Get fantasy football with free live scoring. Sign up for
>>>>> FanHouse Fantasy Football today.
>>>>> (http://www.fanhouse.com/fantasyaffair?ncid=aolspr00050000000020)
>>>>> _______________________________________________
>>>>> Amps mailing list
>>>>> Amps at contesting.com
>>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>>
>>>>> _______________________________________________
>>>>> Amps mailing list
>>>>> Amps at contesting.com
>>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> W9ZY
>>>>> .... Commander John ....
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> W9ZY
>>>>> .... Commander John ....
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Amps mailing list
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>>>>> http://lists.contesting.com/mailman/listinfo/amps
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>>
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